Made available in DSpace on 2014-12-17T14:35:48Z (GMT). No. of bitstreams: 1 AnaliceAL.pdf: 947341 bytes, checksum: 966f1f4ed5e57c11e917c7d3f532de0a (MD5) Previous issue date: 2007-12-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In the past twenty years, there has been a significant increase of researches about teacher s professionalization. In that context, the investigations concerning teacher s knowledge represent an important contribution, as they aim to identify and to rescue the base of knowledge that sustains the teacher s profession. In particular, the reflections and propositions of Lee Shulman have been constitute a fundamental subsidy to the teacher s professionalization in the sense of harnessing the pedagogic knowledge to the content s knowledge, establishing the pedagogic knowledge of the content that characterizes and differentiates the teacher and the bachelor in a certain field of knowledge. Among the indispensable knowledge for the Chemistry teacher's professional practice, in this research we have pointed out the pertinence of the knowledge on the use of models in Chemistry classes in the middle and high school. Those knowledges regard the comprehension of students concerning the understanding and models elaborated in science and the models implemented in the Chemistry teaching, as well as the abilities to plan didactic situations that use models. In this research, we aimed to identify the contributions and barriers during the Chemistry teacher education, in UFRN, in relation to the construction of knowledge that subsidize training teachers in the elaboration of teaching activities that involve the use of models. The investigation was accomplished in UFRN, in the Course of Degree in Chemistry, along with 13 student teachers that studied the subject Practice of Chemistry Teaching. For this research, the following instruments were used: questionnaires with open and closed questions, elaboration of a plan of activities for the Chemistry teaching and an interview to answer the established study s questions. The data was analyzed in an established criteria, classified and tabled. The results showed that the student teachers representations regarding scientific knowledge contemplated, among other topics, the idea of a method for his/her construction. In some cases, the models role was emphasized in that construction, as well as the social dimension in the validation of that knowledge. The scientific models were highlighted by most of the student teachers, as a representation method to explain, understand and interpret the chemical phenomena. On the other hand, the didactic models stood out, in most of cases, as a method of aiding the Chemistry students of the Basic Education to understand the scientific models. The representations regarding those categories contemplated important aspects, although in a superficial way, reflecting the limitations of reflections during the formative process. In the elaboration of teaching activities that use models, difficulties were evidenced, in the process of plan construction, relative to the didactic structure and to the proposition of activities that contemplated models, although the student teachers have mobilized different elements regarding the pedagogic knowledge of the content. Such verifications evidence the urge for the teacher development programs to promote changes in the teacher education in order to propitiate, during this process, reflections, discussions and propositions of activities regarding categories highlighted in this research, contributing to the construction of initial elements regarding the pedagogic knowledge of the content that will be developed throughout teaching, therefore corroborating to the teacher s professionalization / Nos ?ltimos vinte anos, as pesquisas voltadas profissionaliza??o docente t?m crescido de modo expressivo. Nesse contexto, as investiga??es acerca dos saberes docentes representam uma importante contribui??o, visto que buscam identificar e resgatar a base de conhecimento que sustenta a profiss?o docente. Em particular, as reflex?es e proposi??es de Lee Shulman t?m constitu?do um subs?dio fundamental ? profissionaliza??o dos professores no sentido de atrelar os saberes pedag?gicos aos do conte?do, estabelecendo o conhecimento pedag?gico do conte?do que caracteriza e diferencia o professor e o bacharel em determinada ?rea de conhecimento. Entre os saberes imprescind?veis ao exerc?cio profissional do professor de Qu?mica, salientamos, nesta pesquisa, a pertin?ncia dos relativos ao uso de modelos nas aulas de Qu?mica nos ensinos fundamental e m?dio. Esses saberes s?o referentes ? compreens?o dos licenciandos acerca do conhecimento e modelos elaborados na ci?ncia e dos modelos adotados no ensino de Qu?mica, assim como as habilidades para planejar situa??es did?ticas que utilizem modelos. Nesta pesquisa, buscamos identificar as contribui??es e entraves, durante a forma??o inicial de professores de Qu?mica, na UFRN, em rela??o ? constru??o de saberes que subsidiem os licenciandos na elabora??o de atividades de ensino que envolvam a utiliza??o de modelos. A investiga??o foi realizada na UFRN, no Curso de Licenciatura em Qu?mica, junto a 13 licenciandos que cursavam a disciplina de Pr?tica de Ensino de Qu?mica. Para esta pesquisa, foram utilizados os seguintes instrumentos: question?rios com perguntas abertas e fechadas, elabora??o de um plano de atividades para o ensino de Qu?mica e entrevista de modo a responder as quest?es de estudo estabelecidas. Os dados obtidos foram analisados a partir de crit?rios estabelecidos, categorizados e tabelados. Os resultados sinalizam que as representa??es dos licenciandos referentes ao conhecimento cient?fico contemplavam, entre outras quest?es, a id?ia de um m?todo para a sua constru??o. Em alguns casos, foi ressaltado o papel dos modelos nessa constru??o, bem como a dimens?o social na valida??o desse conhecimento. Os modelos cient?ficos foram destacados, pela maioria dos licenciandos, como uma forma de representa??o com finalidade de explicar, compreender e interpretar os fen?menos qu?micos. J? os modelos did?ticos foram ressaltados, na maioria dos casos, como uma forma de auxiliar os alunos de Qu?mica da Educa??o B?sica a compreender os modelos cient?ficos. As representa??es referentes a essas categorias contemplaram aspectos importantes, embora de modo superficial, refletindo as limita??es de reflex?es nesse sentido durante o processo formativo. Na elabora??o de atividades de ensino que utilizam modelos, foram evidenciadas dificuldades, no processo de constru??o do plano, relativas ? estrutura did?tica e ? proposi??o de atividades que contemplassem modelos, embora os licenciandos tenham mobilizado diferentes elementos referentes ao conhecimento pedag?gico do conte?do. Tais constata??es evidenciam a necessidade de que a ag?ncia formadora possa promover mudan?as na forma??o inicial de modo a propiciar, ao longo desse processo, reflex?es, discuss?es e proposi??es de atividades relativas ?s categorias destacadas nesta pesquisa, contribuindo para a constru??o de elementos iniciais referentes ao conhecimento pedag?gico do conte?do que ser?o desenvolvidos no decorrer da doc?ncia, corroborando, dessa forma, para a profissionaliza??o docente

Made available in DSpace on 2014-12-17T14:36:30Z (GMT). No. of bitstreams: 1 JoseEP_TESE.pdf: 4599191 bytes, checksum: d2333069155f93ee6ff447f7f4254297 (MD5) Previous issue date: 2013-02-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / It has been remarkable among the Science Teaching debates the necessity that students do not learn only theories, laws and concepts, but also develop skills which allows them to act towards a critical citizenship. Therefore, some of the skills for the natural sciences learning must be taught consciously, intentionally and in a planned way, as component of a basic competence. Studies of the last twenty years have shown that students and teachers have plenty of difficulties about skills development and, among several, the skill of interpreting Cartesian graphics, essential for the comprehension of Natural Science. In that sense, the development of that type of professional knowledge during the initial education of future Chemistry teachers has become strategic, not only because they need to know how to use it, but also because they need to know how to teach it. This research has as its general objective the organization, development and study of a process of formation of the skill of interpreting Cartesian graphics as part of the teachers professional knowledge. It has been accomplished through a formative experience with six undergraduate students of the Teaching Degree Course of Chemistry of Universidade Federal do Rio Grande do Norte (UFRN Federal University of Rio Grande do Norte), in Brazil. In order to develop that skill, we have used as reference P. Ya. Galperin s Theory of the Stepwise Formation of Mental Actions and Concepts and its following qualitative indicators: action form, degree of generalization, degree of consciousness, degree of independence and degree of solidness. The research, in a qualitative approach, has prioritized as instruments of data collecting the registering of the activities of the undergraduate students, the observation, the questionnaire and the diagnosis tests. At the first moment, a teaching framework has been planned for the development of the skill of interpreting Cartesian graphics based on the presupposed conceptions and steps of Galperin s Theory. At the second moment, the referred framework has been applied and the process of the skill formation has been studied. The results have shown the possibility of develop the skill conscious about the invariant operation system, with a high degree of generalization and internalized the operational invariant in the mental plane. The students have attested the contributions at that type of formative experience. The research reveals the importance of going deeper about the teaching comprehension of the individualities tied to the process of internalization, according to Galperin s Theory, when the update of abilities as part of the teaching professional knowledge is the issue / ? not?ria nas discuss?es da ?rea de Did?tica das Ci?ncias a necessidade de que os estudantes n?o s? aprendam teorias, leis e conceitos, mas que tamb?m desenvolvam habilidades que lhes permitam o agir competente para a cidadania cr?tica. Nessa perspectiva, algumas das habilidades para a aprendizagem das ci?ncias naturais devem ser ensinadas de modo consciente, intencional e planejadas, como componente dessa compet?ncia b?sica. Estudos nos ?ltimos vinte anos t?m mostrado que estudantes e professores t?m diversas dificuldades no desenvolvimento de habilidades, dentre elas, a de interpretar gr?ficos cartesianos, essencial para a compreens?o das Ci?ncias Naturais. Nesse sentido, o desenvolvimento desse conhecimento profissional na forma??o inicial de futuros professores de Qu?mica passa a ser estrat?gico n?o apenas para saber utiliz?-lo, mas para saber ensin?-lo. Esta pesquisa teve como objetivo geral a organiza??o, o desenvolvimento e o estudo de um processo de forma??o da habilidade de interpretar gr?ficos cartesianos como parte do conhecimento profissional docente, a partir de uma experi?ncia formativa com seis estudantes do curso de Licenciatura em Qu?mica da Universidade Federal do Rio Grande do Norte (UFRN). Para o desenvolvimento dessa habilidade, utilizamos como referencial a Teoria da Forma??o por Etapas das A??es Mentais e dos Conceitos de P. Ya. Galperin e seus seguintes indicadores qualitativos: forma da a??o, grau de generaliza??o, grau de consci?ncia, grau de independ?ncia e grau de solidez. A pesquisa, de natureza qualitativa, privilegiou como instrumentos de coleta de dados o registro de atividades dos licenciandos, a observa??o, o question?rio e testes diagn?sticos. No primeiro momento, foi planejado um Sistema Did?tico para o desenvolvimento da habilidade de interpretar gr?ficos cartesianos, com base nos pressupostos e etapas da Teoria de Galperin. No segundo momento, o referido Sistema foi aplicado junto aos licenciandos e o processo de forma??o da habilidade foi desenvolvido. Os resultados mostraram a possibilidade de formar a habilidade com consci?ncia do sistema de opera??es invariante, com alto grau de generaliza??o e internalizada a invariante operacional no plano mental. Os estudantes manifestaram as contribui??es positivas desse tipo de experi?ncia formativa. A pesquisa, por sua vez, revela a import?ncia de se aprofundar na compreens?o did?tica das individualidades no processo de assimila??o, segundo a Teoria de Galperin, quando se trata da atualiza??o de habilidades como parte do conhecimento profissional docente

Made available in DSpace on 2015-03-13T17:08:17Z (GMT). No. of bitstreams: 1 IvaldoRT.pdf: 3649445 bytes, checksum: 624c427ba32cfc36890765f50db5140c (MD5) Previous issue date: 2000-05-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Great part of the gold mineralizations are associated with shearing zones through which circulate a great volume of fluids, that interact with the host rocks, originating leaching or precipitation of chemical elements, including gold. The studied mineralizations are inserted in the Serid? Belt. The tungsten mineralization in Breju? Mine is hosted in calcsilicate rocks from Jucurutu Formation. The S?o Francisco auriferous mineralization has as host rocks mica-schists from Serid? Formation, while the Ponta da Serra and Fazenda Simp?tico mineralizations are hosted in orthogneisses of this fold belt basement. The research conducted on these mineralizations had the purpose of integrate the data of chemical elements behavior during the shearing/mineralizing event, and its influence on the isotopic systems Rb-Sr and Sm-Nd. The studies of chemical mobility in the auriferous mineralizations showed that elements that during the shearing displayed in general an immobile behavior were Al, Ti and Zr. Among the elements that were mobilized during the event, K and Rb showed mass gain in ali belts of transformed rocks, while the elements Ca, Na and Sr normally lost mass. Petrographic studies showed that the minerais biotite and plagioclase, in all investigated mineralizations, played an important role in the chemical reactions occurred in the transformed rocks to the generation of muscovite, cordierite and sillimanite, justifying the input of K to the formation of muscovite, and the release of Na and Ca from plagioclase to the fluid phase. In the S?o Francisco auriferous mineralization, the results of the Rb-Sr isotopic analysis yielded ages of 645 ? 19 Ma and 596 ? 17 Ma, with both samples, from original and transformed rocks. Two ages, 569 ? 20 Ma. and 554 ? 19 Ma., were obtained with samples frem the transformed rocks domain. These ages suggest that there were two metamorphic pulses during the emplacement of the mineralized shearing zone. The Sm-Nd data yielded TDM ages of 1,31 Ga and 1,26 Ga with 3Nd (0,6 Ga) of -0,26 e -0,40 for the original and final transformed rocks, respectively. In case of the orthogneisses of Caic? Complex, e.g. the Ponta da Serra and Fazenda Simp?tico mineralizations, the Rb-Sr data did not yield ages with geological significance. In the Ponta da Serra mineralization, the Sm-Nd isotopic data yielded T DM ages of 2,56 Ga and 2,63 Ga to the original rocks and of 2,71 Ga to the mineralized sheared rock, and values of 3Nd (2,0 Ga) between -3,70 e -5,42 to the original and sheared rock, respectively. In the Fazenda Simp?tico, Sm-Nd data yielded TDM between 2,65 and 2,69 Ga with values of 3Nd (2,0 Ga) between -5,25 e -5,52. Considering the Sm-Nd data, the TDM ages may be admitted as the age of the parental magma extraction, producer of the protoliths of the orthogneisses from Ponta da Serra and Fazenda Simp?tico mineralizations. The chemical mobility studies showed that in the basement hosted mineralizations, Rb achieved mass while Sr lost mass, as Sm as well as Nd were strongly mobilized. The Sm/Nd ratio remained constant, however, confirming the isochemical character of those elements. In the basement mineralizations, Rb-Sr ages are destituted of geological significance, because of the partial opening of the isotopic system during the tectono-metamorphic transformations. In the tungsten mineralization, the diagram Sm-Nd constructed with the whole-rock data of calcsilicatic and the high-temperature paragenesis (garnet, diopside and iron-pargasitic hornblende) indicated an 631 ? 24 Ma age, while with the whole-rock data and low-temperature paragenesis (vesuvianite, epidote and calcite), a 537 ? 107 Ma age was obtained. These ages, associated with the petrographic observations, suggest that there was a time gap among the hydrothernal events responsible by the formation of the high and low temperature paragenesis in the calcsilicatic rocks mineralized in scheelite / As mineraliza??es estudadas est?o inseridas na Faixa de dobramento Serid?. A scheelit?fera de Breju? est? hospedada em rochas calciossilic?ticas da Forma??o Jucurutu. A mineraliza??o aur?fera de S?o Francisco tem como hospedeiros micaxistos da Forma??o Serid?, enquanto que as mineraliza??es de Ponta da Serra e da Fazenda Simp?tico est?o hospedadas em ortognaisses do embasamento desta faixa de dobramentos. Grande parte das mineraliza??es de ouro est?o associadas ? zonas de cisalhamento que funcionam como conduto para a circula??o de um grande volume de fluidos, que interagem com as rochas hospedeiras provocando lixivia??o ou precipita??o de elementos qu?micos, incluindo o ouro. Estas foram algumas das principais caracter?sticas observadas nas mineraliza??es aqui estudadas. A pesquisa realizada nas mineraliza??es de ouro teve a finalidade de integrar os dados do comportamento de elementos qu?micos durante o evento cisalhamento/mineralizante, e sua influ?ncia nos sistemas isot?picos Rb-Sr e Sm-Nd. Os estudos de mobilidade qu?mica mostraram que os elementos, que durante o cisalhamento, de uma forma geral apresentaram um coportamento im?vel, foram o AI, Ti e Zr. Dentre os elementos que foram mobilizados durante o evento, o K e o Rb mostraram ganho de massa em todas as faixas de rochas transformadas, enquanto que os elementos Ca, Na e o Sr normalmente perderam massa. Os elementos Sm e Nd na mineraliza??o de S?o Francisco se comportaram como im?veis e em Ponta da Serra e Fazenda Simp?tico perderam massa. Os estudos petrogr?ficos mostraram que os minerais biotita e plagiocl?sio, em todas as mineraliza??es estudadas, tiveram papel importante nas rea??es qu?mica ocorridas nas rochas transformadas para a gera??o de muscovita, cordierita e silimanita, justificando a entrada do K para forma??o da muscovita e da libera??o de Na e Ca do plagiocl?sio para a fase fluida. Na mineraliza??o aur?fera de S?o Francisco, os resultados das an?lises isot?picas de Rb e Sr, forneceram idades de 645 ? 19 Ma e de 596 ? 17 Ma com amostras das rochas originais e transformadas juntas. Duas idades, 569 ? 20 Ma e 554 ? 19 Ma foram obtidas com as amostras do dom?nio das rochas transformadas. Estas idades s?o sugestivas de que houve dois pulsos metam?rficos durante a instala??o da zona de cisalhamento mineralizada. Os dados Sm-Nd forneceram idades TDM de 1,31 Ga e de 1,26 Ga com 3Nd (0,6 Ga) de -0,26 e -0,40 respectivamente para a rocha original e transformada final. Para os ortognaisses do Complexo Caic?, caso da mineraliza??o de Ponta da Serra e da Fazenda Simp?tico, os dados Rb-Sr n?o forneceram idades com significado geol?gico. Na mineraliza??o de Ponta da Serra, os dados isot?picos Sm-Nd forneceram idades T DM de 2,56 Ga e 2,63 Ga para as rochas originais e de 2,71 Ga para a rocha cisalhada, mineral?zada e valores de 3Nd (2,0 Ga) entre -3,70 e -5,42 para rocha original e cisalhada respectivamente. Na Fazenda Simp?tico os dados de Sm-Nd forneceram as idades T DM ficaram entre 2,65 e 2,69 Ga com valores de 3Nd (2,0 Ga) entre -5,25 e -5,52. Quanto aos dados Sm-Nd as idades T DM podem ser admitidas como a idade de extra??o do magma parental formador dos prot?l?tos dos ortognaisses das mineraliza??es Ponta da Serra e da Fazenda Simp?tico. Os valores de 3Nd baixos e negativos sugerem uma fonte crustal, ou a participa??o de duas fontes (mantocrosta) . Os estudos de mobilidade qu?mica mostraram que nas mineraliza??es hospedadas no embasamento, o Rb ganhou massa enquanto o Sr perdeu massa e tanto o Sm quanto o Nd, foram fortemente mobilizados. As raz?es Sm/Nd entretanto se mantiveram constantes, confirmando o car?ter isoqu?mico destes elementos. Nas mineraliza??es do embasamento, idades pelo m?todo Rb-Sr s?o desprovidas de significado geol?gico, em fun??o da abertura parcial do sistema isot?pico durante as transforma??es tectonometam?rficas. Na mineraliza??o scheelit?fera foi realizado um estudo geocronol?gico Sm-Nd com o intuito de se obter as idades das parag?neses formadas durante os eventos hidrotermais sofridos pelas rochas calciossilic?ticas mineralizadas. O diagrama Sm-Nd constru?do com os dados de rocha total e parag?nese de alta temperatura (granada, diops?dio e hornblenda ferropargas?tica) forneceu uma idade de 631 ? 24 Ma, e com os dados de rocha total e parag?nese de baixa temperatura (vesuvianita, epidoto e calcita), foi obtida uma idade de 537 ? 107 Ma. Estas idades associadas com as observa??es petrogr?ficas sugerem que houve um lapso de tempo entre os eventos hidrotermais respons?veis pelas forma??es das parag?neses de alta e de baixa temperatura nas rochas calciossilic?ticas mineralizadas em scheelita

Made available in DSpace on 2014-12-17T14:58:03Z (GMT). No. of bitstreams: 1 JoaoBSC_DISSERT_1-40.pdf: 4020421 bytes, checksum: 0d899aaf278ef09b1ceedc1d8064ebc4 (MD5) Previous issue date: 2010-08-27 / In this work a solar drying system for food dehydration was developed. It is a direct exposition drying apparatus that uses solar energy to heat the circulating air. First, the construction and assembly of this apparatus was described, in which was used scrap wraps of used tires for thermal insulation, allowing the reuse of solid waste, being an ecologically correct recycling option. After, the results obtained in experiments for cashew drying showed the thermal and economical feasibility of the proposed solar drying system, focusing on the process of flour production and in its chemical characterization. It was also demonstrated the social importance of this production for socially excluded people, since the value added to this fruit, in relation to its in nature form, may represent an option for job and income generation. The main features of the proposed dryer are its low cost and its easy fabrication and assembly process. After cashew drying, the obtained product was processed into flour by using a knife mill and it was added crushed rapadura to reduce the rancid taste caused by tannin / Apresenta-se um sistema de secagem solar para a desidrata??o de alimentos utilizando um secador de exposi??o direta que trabalha em regime de circula??o natural. Abordam-se os processos de constru??o e montagem desse secador que utiliza isolante t?rmico de raspa de pneu, permitindo a reutiliza??o de materiais, constituindo-se numa op??o ambientalmente correta de reciclagem. O trabalho apresenta resultados de testes realizados para a secagem do caju que atestam as viabilidades t?rmicas e econ?micas do sistema de secagem solar proposto enfocando o processo de produ??o da farinha e an?lises qu?micas para caracteriz?-la. Ser? tamb?m demonstrada a import?ncia social que essa produ??o representa para a popula??o mais exclu?da uma vez que o valor agregado a essa fruta, em rela??o ao in natura, pode representar uma op??o de gera??o de emprego e renda. As principais caracter?sticas do secador proposto s?o seu baixo custo e simples processo de fabrica??o e montagem. Ap?s seco o caju foi transformado em farinha por meio de um moinho de faca, e posteriormente, foi adicionada rapadura triturada para amenizar o sabor ran?oso provocado pelo tanino

Made available in DSpace on 2014-12-17T15:01:45Z (GMT). No. of bitstreams: 1 IranML.pdf: 679853 bytes, checksum: 41b8ab13f1034bf3dbc30705bfdf84e4 (MD5) Previous issue date: 2008-04-14 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The objective of this scientific article is to introduce the opportunities of implementation of cleaner production (CP) in a shrimp culture farm. The methodology used for this was exploratory research implemented in a production unit located in the Northeast Brazil. The scientific article approaches since generic aspects of the technique about the management to use water, energy and the effluent characterization of this productive activity. It discusses quantitative aspects, environmental questions and chances of P+L during the productive process phases. The results points to input economy in the form of feed, soil correctives, medicines, and energy applied to the process, which range from 4% to 27%, emphasizing the small profit should be viewed as a source of considerable environment return. The authors conclude for the adoption property of this technique in this agribusiness segment, point out to the management importance of the input dosage in the quality of the final effluent, besides the adoption of a physical-chemistry remediation mechanism to the residual of Sodium metabissulphite used in the process of shrimp caught / O objetivo do trabalho ? apresentar uma estrat?gia de implementa??o da produ??o mais limpa (P+L) em uma fazenda de cultivo de camar?es. A metodologia utilizada foi pesquisa explorat?ria, realizada pela investiga??o via estudo de caso, implementada em uma unidade produtiva localizada no nordeste do Brasil. O trabalho aborda desde aspectos gen?ricos da t?cnica no que diz respeito ao gerenciamento do uso da ?gua, energia, e da caracteriza??o do efluente desta atividade produtiva. Discute aspectos quantitativos, considera??es ambientais, e oportunidades de P+L nas fases do processo produtivo. Os resultados apontam para economias de insumos sob a forma de alimentos, corretivos de solo, medicamentos, e energia aplicados ao processo, que variam de 4 a 27%, ressaltando-se que o pequeno ganho financeiro, deve ser encarado como uma fonte de consider?vel benef?cio ambiental. Os autores concluem pela propriedade da ado??o da t?cnica neste segmento do agroneg?cio, ressaltando a import?ncia do gerenciamento da dosagem de insumos na qualidade do efluente final, al?m da ado??o de um mecanismo de remedia??o f?sico-qu?mica para o residual de metabissulfito de s?dio utilizado na despesca

Made available in DSpace on 2014-12-17T15:05:04Z (GMT). No. of bitstreams: 1 RogerioGA_DISSERT.pdf: 8092447 bytes, checksum: 8092c9fc8e1a9696dd331b3c086d01ac (MD5) Previous issue date: 2013-09-05 / The National Program of Professional Education Integration with Basic Education for Youngsters and Adults (PROEJA) Technical Professional Education Ensino M?dio has opened a new chapter in the history of education in Brazil, making possible the integration of basic education and professional education. This new form of education, which is still in its early implementation, presents a series of challenges to be overcome. Specifically about the teaching of Chemistry, didactic material to match PROEJA s specific needs is practically inexistent. Thus, this work has the purpose of developing didactic material for the teaching of Chemistry for Professional and Technological Education of Youngsters and Adults in the courses of Electronics, Technical Electronics and Maintenance and Support for Computing at Instituto Federal de Educa??o,Ci?ncia e Tecnologia do Rio Grande do Norte. This material aims at working chemical concepts of oxi-reduction reactions through a theme approach following Freire s conceptions for the teaching of Youngsters and Adults / O Programa Nacional de Integra??o da Educa??o Profissional com a Educa??o B?sica na Modalidade de Educa??o de Jovens e Adultos - Educa??o Profissional T?cnica de N?vel M?dio / Ensino M?dio (PROEJA) abriu um novo cap?tulo na hist?ria da educa??o de jovens e adultos, possibilitando a integra??o da educa??o profissional ? educa??o b?sica. Essa modalidade de educa??o, que ainda se encontra em fase inicial de implementa??o, apresenta uma s?rie de desafios a serem superados. No caso espec?fico de ensino de Qu?mica, ? praticamente inexistente material did?tico elaborado para atender ?s especificidades dos alunos do PROEJA. Nesse sentido, tivemos como prop?sito, no presente trabalho, o desenvolvimento de um material did?tico para o ensino de Qu?mica na Educa??o Profissional e Tecnol?gica de Jovens e Adultos nos cursos de eletr?nica, eletrot?cnica e manuten??o e suporte em inform?tica oferecidos pelo Instituto Federal de Educa??o,Ci?ncia e Tecnologia do Rio Grande do Norte. Esse material did?tico tem como objetivo trabalhar o conceito qu?mico de rea??es de oxirredu??o atrav?s de uma abordagem tem?tica seguindo as concep??es freireanas para Educa??o de Jovens e Adultos

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-10-25T23:47:12Z No. of bitstreams: 1 LuisVictorDosSantosLima_DISSERT.pdf: 1575562 bytes, checksum: 761fdb9d280d0bb7891a692f3c67f049 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-12-16T22:06:21Z (GMT) No. of bitstreams: 1 LuisVictorDosSantosLima_DISSERT.pdf: 1575562 bytes, checksum: 761fdb9d280d0bb7891a692f3c67f049 (MD5) / Made available in DSpace on 2016-12-16T22:06:21Z (GMT). No. of bitstreams: 1 LuisVictorDosSantosLima_DISSERT.pdf: 1575562 bytes, checksum: 761fdb9d280d0bb7891a692f3c67f049 (MD5) Previous issue date: 2016-04-11 / A disserta??o ? fruto de uma investiga??o realizada com professores e estudantes do ensino m?dio sobre suas concep??es de g?nero e natureza da ci?ncia. Com base em referenciais e estudos que tratam das rela??es de g?nero na ci?ncia, quest?es foram levantadas, pesquisadas e discutidas neste trabalho visando promover reflex?es a cerca das consequ?ncias que vis?es distorcidas e ing?nuas podem causar no ensino de ci?ncias. Perante um p?blico participante constitu?do por 91 estudantes e 4 professores do ensino m?dio, realizamos uma pesquisa-a??o no intento de explorar como compreendem ci?ncia e g?nero assim como a rela??o desses campos. Por meio de dois instrumentos de pesquisa, um question?rio e um roteiro de entrevista semiestruturado, as concep??es desses indiv?duos foram coletadas, tratadas e discutidas mediante uso da an?lise de conte?do. Os resultados indicam que quase todos os estudantes e alguns professores compreendem a ci?ncia numa perspectiva neutra, salvacionista, positivista, em que a figura masculina de cientista como protagonista ? predominante. Partindo desse diagn?stico foi constru?da uma sequ?ncia did?tica para o conte?do ?Lei de Conserva??o das Massas? em que buscou-se evidenciar o car?ter cooperativo da atividade cient?fica, mediante a exposi??o da colabora??o de outros cientistas para o estabelecimento dessa lei. O uso da hist?ria da ci?ncia no ensino de qu?mica, e demais ?reas das ci?ncias naturais, pode contribuir para que os estudantes tenham uma compreens?o mais humanizada da cultura cient?fica, possibilitando discuss?es e debates pertinentes ? rela??o ?tica e social. / This dissertation is the result of research conducted with high school teachers and students about their conceptions of gender and nature of science. Based on references and studies dealing with gender relations in science, questions have been raised, researched and discussed in this work, to promote reflections on the possible consequences of distorted and naive visions can cause in science education. In Brazilian educational documents, there are recommendations for addressing the nature of science in high school, present constructivist character, however, which is widespread, both in the discourse of some teachers and in teaching materials is far from what is proposed. It is necessary to promote increased scientific literacy of students - not only understanding and mastery of codes and concepts of science, but the understanding of aspects related to scientific culture. With 91 students and 3 teachers and a high school teacher, we conducted a survey in an attempt to investigate how they understand science and gender as well as the relationship between these fields. Through two research instruments, a questionnaire and a semistructured interview guide, the views of these individuals were collected, treated and discussed by using content analysis. The results indicate that almost all students and some teachers understand science as neutral, Salvationists, positivistic, in which the male figure scientist protagonist is predominant; the students and the teachers, there is no knowledge of women scientists in the history of science; as the reasons for the small number of women in the sciences courses, the public assigns founded justifications mainly in biological determinism and essentialism. Based on this diagnosis, it was built a didactic sequence consisting of 4 classes which sought to highlight the cooperative nature of scientific activity through collaboration exposure of other scientists, including women. For each class has produced a text support making use of the history of science in chemistry education and other areas of the natural sciences. The use of history of science assumes that it can help students to have a more human understanding of scientific culture, enabling discussions and debates relevant to ethics and social relationship. The application of this teaching sequence allowed a better understanding of issues surrounding the nature of science, deconstructing myths that were diagnosed at baseline, as well as allowed the discussion of relevant chemical concepts in this level of education. It is necessary that the school curriculum, through the approach of its contents, provides the training of students for citizenship critically. We need to discuss various social issues such as gender, race, ethnicity, with a view to exploring the diversity, in an attempt to promote new learning.

Made available in DSpace on 2014-12-17T15:42:28Z (GMT). No. of bitstreams: 1 MariaJFC_TESE.pdf: 4007652 bytes, checksum: 7bb363c54641679d79bbff5c76de539f (MD5) Previous issue date: 2013-06-03 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The processing of heavy oil produced in Brazil is an emergency action and a strategic plan to obtain self-sufficiency and economic surpluses. Seen in these terms, it is indispensable to invest in research to obtain new catalysts for obtaining light fraction of hydrocarbons from heavy fractions of petroleum. This dissertation for the degree of Doctor of Philosophy reports the materials preparation that combine the high catalytic activity of zeolites with the greater accessibility of the mesoporosity, more particularly the HZSM-5/MCM-41 hybrid, done by synthesis processes with less environmental impact than conventional ones. Innovative methodologies were developed for the synthesis of micro-mesoporous hybrid material by dual templating mechanism and from crystalline zeolitic aluminosilicate in the absence of organic template. The synthesis of hybrid with pore bimodal distribution took place from one-single organic directing agent aimed to eliminate the use of organic templates, acids of any kind or organic solvents like templating agent of crystalline zeolitic aluminosilicate together with temperature-programmed microwave-assisted, making the experimental procedures of preparation most practical and easy, with good reproducibility and low cost. The study about crystalline zeolitic aluminosilicate in the absence of organic template, especially MFI type, is based on use of H2O and Na+ cation playing a structural directing role in place of an organic template. Advanced characterization techniques such as X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Highresolution Transmission Electron Microscopy (HRTEM), Adsorption of N2 and CO2, kinetic studies by Thermogravimetric Analysis (TGA) and Pyrolysis coupled to Gas Chromatography/Mass Spectrometry (Pyrolysis-GC/MS) were employed in order to evaluate the synthesized materials. Achieve the proposed objectives, has made available a set of new methodologies for the synthesis of zeolite and hybrid micro-mesoporous material, these suitable for catalytic pyrolysis of heavy oils aimed at producing light fraction / O processamento do petr?leo pesado produzido no Pa?s ? uma a??o emergencial e estrat?gica para obter a auto-sufici?ncia e super?vits econ?micos. Neste sentido, ? indispens?vel o investimento em pesquisas de novos catalisadores para obten??o de derivados leves a partir de fra??es pesadas do petr?leo. O trabalho de doutorado aqui reportado dedicouse ? prepara??o de materiais que combinem, numa ?nica estrutura, a elevada atividade catal?tica de ze?litas, com melhor acessibilidade de materiais mesoporosos, como a estrutura h?brida HZSM-5/MCM-41, utilizando processos de s?ntese com menor impacto ambiental que os convencionais. Metodologias inovadoras foram desenvolvidas para a s?ntese do catalisador h?brido micro-mesoporoso ou ze?lito-mesoporoso por mecanismo de direcionamento estrutural via duplo agente diretor org?nico e tamb?m a partir de estrutura zeol?tica sintetizada na aus?ncia total de direcionador org?nico. Esse ?ltimo, tamb?m chamado de s?ntese do h?brido com distribui??o bimodal de poros a partir de um ?nico agente diretor org?nico, visou eliminar o uso dos direcionadores org?nicos, ?cidos de qualquer natureza ou solventes org?nicos como molde estrutural da estrutura zeol?tica em conjunto com o m?todo hidrot?rmico assistido por irradia??o via micro-ondas, tornando o procedimento experimental de prepara??o pr?tico e simples, com boa reprodutibilidade e menor custo. A metodologia de prepara??o da ze?lita MFI do tipo ZSM-5 utiliza H2O e c?tions Na+ no papel de direcionamento estrutural e compensa??o de cargas na estrutura. T?cnicas relevantes de caracteriza??o, como Difra??o de Raios-X (XRD), Espectroscopia no Infravermelho com Transformada de Fourier (FTIR), Microscopia Eletr?nica de Varredura (SEM), Microscopia Eletr?nica de Transmiss?o de Alta Resolu??o (HRTEM), Adsor??o de N2 e CO2, estudos cin?ticos via An?lises Termogravim?tricas (TGA) e Pir?lise acoplada ? Cromatografia Gasosa/Espectrometria de Massas (Pyrolysis-GC/MS), foram empregadas no intuito de avaliar os materiais sintetizados. Alcan?ados os objetivos propostos, disponibilizou-se um conjunto de novas metodologias para s?ntese de catalisadores zeol?ticos e h?bridos micromesoporosos, estes adequados para pir?lise catal?tica de ?leos pesados visando ? produ??o de derivados leves

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-11-09T17:58:22Z No. of bitstreams: 1 2017 - Mariana de Albuquerque Almeida.pdf: 2619920 bytes, checksum: 48c00262629bac9a7779fc4ea9ec94a6 (MD5) / Made available in DSpace on 2017-11-09T17:58:22Z (GMT). No. of bitstreams: 1 2017 - Mariana de Albuquerque Almeida.pdf: 2619920 bytes, checksum: 48c00262629bac9a7779fc4ea9ec94a6 (MD5) Previous issue date: 2017-05-10 / CAPES / This dissertation presents the evaluation of four thiosemicarbazones, from extracts of species of vegetables Talinum triangulare, Physalis angulata e Theobroma cacao L. besides formulation obtained from the combination extract of thiosemicarbazones vegetables as corrosion inhibitor in the presence of carbon steel AISI 1020. Thiosemicarbazones were obtained with good level of purity, satisfactory throughput and identified by NMR of 1H and 13C. The watery extract of Talinum triangulare was obtained using ultrasound device. The extracts of Physalis angulata species were obtained by maceration in water and the other one in ethyl acetate. The watery extracts of Theobroma cacao L. species were obtained using ultrasound device and decoction and hydroalcoholic extract was obtained by maceration in ethanol:water (80:20). The thiosemicarbazones, the vegetable extracts and their formulation were tested in the presence of corrosion of carbon steel AISI 1020 in solution 1 mol. L-1 of HCl. For this evaluation it was used the gravimetric techinique of weight loss and electrochemical techiniques of potentiodynamic polarization and electrochemical impedance spectroscopy. The results showed that the presence of thiosemicarbazones, as well as, the formulation increased significantly the resistence of carbon steel AISI 1020 in acidic medium. The results obtained in different used essays (weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy) show that these techniques are complementary in relation to the evaluation of corrosion inhibition. The best anti-corrosion efficiency was observed for thiosemicarbazone chloro and hydroxy-substituted and its formulations with the extract of T. triangulare achieving 88% and 87% of efficiency, by electrochemical impedance spectroscopy, respectively. / Nesta Tese ? apresentada a avalia??o de quatro tiossemicarbazonas, dos extratos das esp?cies vegetais Talinum triangulare, Physalis angulata e Theobroma cacao L., al?m de formula??es obtidas pela combina??o extrato vegetal:tiossemicarbazonas, como inibidores de corros?o frente ao a?o carbono AISI 1020 em meio de ?cido cloridr?co. As tiossemicarbazonas foram obtidas com bom grau de pureza, em rendimentos satisfat?rios e, caracterizadas por IV, RMN de ^1H e ^13C. O extrato aquoso de Talinum triangulare foi obtido em aparelho de ultrassom, os extratos da esp?cie Physalis angulata, foram obtidos sob macera??o em ?gua e o outro em acetato de etila; j? os extratos aquosos da esp?cie Theobroma cacao L. foram obtidos em aparelho de ultrassom e decoc??o e, finalmente, o extrato hidroalco?lico foi obtido por macera??o em etanol:?gua (80:20). As tiossemicarbazonas, os extratos vegetais e suas formula??es foram testadas frente ? corros?o de a?o carbono AISI 1020 em solu??o 1mol.L-1 de HCl. Para tal avalia??o foi utilizada a t?cnica gravim?trica de Perda de Massa e as t?cnicas eletroqu?micas de Polariza??o Potenciodin?mica e Espectroscopia de Imped?ncia Eletroqu?mica. Os resultados mostraram que a presen?a de tiossemicarbazonas, bem como, das formula??es aumentam significativamente a resist?ncia do a?o carbono AISI 1020 em ?cido. Os resultados obtidos nos diferentes ensaios utilizados (Perda de Massa, Polariza??o Potenciodin?mica e Espectroscopia de Imped?ncia Eletroqu?mica) mostraram que estas t?cnicas s?o complementares quanto a avalia??o da inibi??o da corros?o. A melhor efici?ncia anticorrosiva foi observada para as tiossemicarbazonas cloro e hidroxi-substitu?das e, para suas formula??es com o extrato da T. triangulare obtendo-se 88% e 87% de efici?ncia por espectroscopia de imped?ncia eletroqu?mica, respectivamente.

Made available in DSpace on 2014-12-17T15:41:45Z (GMT). No. of bitstreams: 1 MariaJFCpdf.pdf: 4931245 bytes, checksum: 45a7ea893d17f478c73adf56787579aa (MD5) Previous issue date: 2008-12-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present work reports the study of nanoporous structures, aiming at their use in research directed to the current demand of the petroleum industry to value heavy oil. Initially, two ways were chosen for the synthesis of porous structures from the molecular sieves of type Si-MCM-41. In the first way, the structure MCM-41 is precursory for heteroatom substitutes of silicon, generating catalyst of the type Al-MCM-41 from two different methods of incorporation of the metal. This variation of the incorporation method of Aluminum in the structure of Si-MCM-41 was carried out through the conventional procedure, where the aluminum source was incorporated to the gel of synthesis, and the procedure post-synthesis, where the Aluminum source was incorporated in catalyst after the synthesis of Si-MCM-41. In the second way, the MCM-41 acts as a support for growth of nanocrystals of zeolite embedded in their mesoporous, resulting in hybrid MCM-41/ZSM-5 catalyst. A comparative analysis was carried through characterizations by XRD, FTIR, measures of acidity through n-butylamine adsorption for TGA, SEM-XRF and N2 adsorption. Also crystalline aluminosilicate with zeolitic structure MFI of type ZSM-5 was synthesized without using organic templates. Methodologies to the preparation of these materials are related by literature using conventionally reactants that supply oxides of necessary silicon and aluminum, as well as a template agent, and in some cases co-template. The search for new routes of preparation for the ZSM-5 aimed at, above all, the optimization of the same as for the time and the temperature of synthesis, and mainly the elimination of the use of organic templates, that are material of high cost and generally very toxic. The current study is based on the use of the H2O and Na+ cations playing the role of structural template and charge compensation in the structure. Characterizations by XRD, FTIR, SEM-XRF and N2 adsorption were also conducted for this material in order to compare the samples of ZSM-5 synthesized in the absence of template and those used industrially and synthesized using structuring / O presente trabalho relata o estudo de estruturas nanoporosas, visando o uso em pesquisas que atendam a atual demanda da ind?stria do petr?leo, de valorizar ?leos pesados. Inicialmente, optou-se por duas vertentes para a s?ntese de estruturas porosas a partir da peneira molecular do tipo Si-MCM-41. Na primeira vertente, a estrutura MCM-41 ? precursora para hetero?tomos substituintes do sil?cio, gerando catalisadores do tipo Al-MCM-41 a partir de dois diferentes m?todos de incorpora??o do metal. Essa varia??o do m?todo de incorpora??o do Alum?nio na estrutura do Si-MCM-41 se deu atrav?s do procedimento convencional, no qual a fonte de alum?nio foi incorporada ao gel de s?ntese e do procedimento p?s-s?ntese, no qual a fonte de Alum?nio foi incorporada ao catalisador ap?s a s?ntese do Si-MCM-41. Na segunda vertente, o MCM-41 age como suporte para o crescimento de nanocristais de ze?lita embutidos nos seus mesoporos, resultando no catalisador h?brido MCM-41/ZSM-5. Uma an?lise comparativa foi realizada atrav?s de caracteriza??es por XRD, FTIR, medidas de acidez atrav?s de dessor??o de n-butilamina por TGA, SEM-XRF e Adsor??o de N2. Tamb?m foi sintetizado um aluminossilicato cristalino com estrutura zeol?tica MFI do tipo ZSM-5, na aus?ncia total de direcionador org?nico. Metodologias relacionadas ? prepara??o desses materiais s?o relatadas pela literatura utilizando-se convencionalmente reagentes que forne?am os ?xidos de sil?cio e de alum?nio necess?rios, bem como um agente direcionador, e em alguns casos at? co-direcionadores. A busca por novas rotas de prepara??o para a ZSM-5 visou, sobretudo, a otimiza??o da mesma no que se refere ao tempo e ? temperatura de s?ntese, e principalmente a elimina??o do uso dos direcionadores org?nicos, que s?o materiais de alto custo e geralmente muito t?xicos. O atual estudo se baseia na utiliza??o da H2O e dos c?tions Na+ desempenhando o papel de direcionamento estrutural e compensa??o de cargas na estrutura. Caracteriza??es por XRD, FTIR, SEM-XRF e Adsor??o de N2 tamb?m foram realizadas para esse material, a fim de comparar as amostras de ZSM-5 sintetizadas na aus?ncia do direcionador e aquelas utilizadas industrialmente e sintetizadas utilizando estruturantes