Ensino de ciências e matemática, VI: ensino de química

Organizado por João José Caluzi e Silvia Regina Quijadas Aro Zuliani, este livro traz uma série de estudos nos quais os autores procuram discutir o ensino da Química à luz da História da Ciência e das metodologias científicas consagradas pelas instituições de ensino brasileiras na disseminação dos conhecimentos sobre a matéria, sempre com um viés analítico e por vezes bastante crítico. A coletânea aborda desde uma proposta de integração da Filosofia da Química no currículo e na didática da matéria até a prevenção de acidentes na execução de experimentos de Química no ensino médio, passando por um balanço crítico sobre as obras de Química adotadas no Programa Nacional do Livro Didático para o Ensino Médio e da utilização e avaliação dos objetos de aprendizagem por professores de Química nas salas de aula brasileiras. A obra também fala do ensino da Química do ponto de vista mais específico, como nos artigos que discutem os pressupostos históricos e filosóficos sobre o princípio da incerteza, a tentativa de uma leitura kuhniana do conceito de substância e o estudo do termo densidade como obstáculo verbal à compreensão dos conceitos.

Measurement of Radiant Energy using Pyroelectric Polymer/Ceramic Composite

Monitoring non-ionizing radiant energy is increasingly demanded for many applications such as automobile, biomedical and security system. Thermal type infrared (IR) sensors can operate at room temperature and pyroelectric materials have high sensitivity and accuracy for that application. Working as thermal transducer pyroelectric sensor converts the non-quantified thermal flux into the output measurable quantity of electrical charge, voltage or current. In the present study the composite made of poly(vinylidene fluoride) -PVDF and lead zirconate titanate (PZT) partially recovered with polyaniline (PAni) conductor polymer has been used as sensor element. The pyroelectric coefficient p(T) was obtained by measuring the pyroelectric reversible current, i.e., measuring the thermally stimulated depolarization current (TSDC) after removing all irreversible contribution to the current such as injected charge during polarization of the sample. To analyze the sensing property of the pyroelectric material, the sensor is irradiated by a high power light source (halogen lamp of 250 W) that is chopped providing a modulated radiation. A device assembled in the laboratory is used to change the light intensity sensor, an aluminum strip having openings with diameters ranging from 1 to 10 mm incremented by one millimeter. The sensor element is assembled between two electrodes while its frontal surface is painted black ink to maximize the light absorption. The signal from the sensor is measured by a Lock-In amplifier model SR530 -Stanford Research Systems. The behavior of the output voltage for an input power at several frequencies for PZT-PAni/PVDF (30/ 70 vol%) composite follows the inverse power law (1/ f) and the linearity can be observed in the frequency range used.

O Ensino de Acústica nos livros didáticos de Física recomendados pelo PNLEM: análise das ligações entre a física e o mundo do som eda música

This paper presents an analysis of the content in acoustics present in physics textbooks recommended by PNLEM, which used the same criteria of evaluation from used by experts in the analysis of such books. In this way, we observed that such texts have evolved little in comparison with the textual presentations reviewed in 1998 and published in the journal Science and Education [1], which were analyzed ten physics textbooks for high school, among which the most commom, at the time, in Brazilian schools. Although we identified the inclusion of some aspects of the culture of sound and music, there are still several conceptual and historical distortions, besides the little importance has been given to links CTSA, among them, studies of soundscapes that, even, are mentioned.

Elementos sociais para a compreensão do prestígio científico e de seus riscos

Natural sciences have an enormous status in public opinion. Their achievements, which become known mostly by means of technology, give to them social credibility, unconditional support and positive social expectances. Further, their social images, generated by the success of their products, tend to lead people to develop only favorable ideas about scientists and about how science works, which are even more reinforced in the schools. By another side, the history of science has been allowed us to comprehend the internal and external social relations concerning to science, showing it as a field of disputes, interests and contradictions as many other fields which comprise human relations. Therefore, the objective of this text is to present social elements of the construction and impacts of natural science, aiming at putting in evidence the importance of the social studies of the scientific world for the courses of education of science teachers.

Ação comunicativa na organização do primeiro encontro de ex-alunos de licenciatura em física

In this paper, we aim to understand the discourses of public school teachers who were former students of an Undergraduate Physics Education course, when they are perceived as actors speakers a public sphere concerned about teacher eduaction. So, we focused virtual dialogues occurred between these former students and a professor of the same course during the organization of the First Meeting of Ex-students inserted in an annual event called Meeting of the Teaching Practice in Physics of Ilha Solteira (ENPEFIS). Thus, we analyze these dialogues according to concepts of public sphere, communicative action and teachers as intellectuals according to elements of the content analysis of these virtual dialogues. Therefore, we envision in this work an important discussion for science teaching , since it reflects briefly on Physics Education committed to discussing science teaching in order to overcome the dogmatic and instrumental science education.

Agrotóxicos - toxidade versus custos: uma experiência na formação de professores com as questões sociocientíficas no ensino de ciências

In this paper, we propose the socio-scientific issues (SSI) as an effective part of the curriculum of the ideals of the STSE movement in education. Furthermore, we have developed in a secondary school, in a rural community in the state of São Paulo, activities of continuing education for teachers in the discussions of SSI in the classroom. To understand and reflect on the situations resulting from these practices, we considered the participant research and the content analysis from the audio records of the weekly meetings between the teachers of this school and graduate students from a nearby university.Given this,we could understand how these issues should be part of people's lives, teachers must present motivation for the work, they need information,exposition of the arguments involved, mustrelate content and curricula, but, all this,aiming at the necessary critics of the aspects that can make this an instrumentalized practice. At the end of this clipping of our doctoral research, we were able to consider evidences on how teachers were inserted in the training process, with their involvement in the discussions and practices with the ISS.

A constituição de uma questão sociocientífica em um grupo de professores: um processo polifônico de desvelamento da realidade concreta

This article presents part of a broader research and seeks to elucidate the process of setting up a Socio-scientific Issue in a group of teachers at a public school. Assuming that a Socioscientific Issue must aggregate those involved in the educational process in situations of dialogue, argumentation and construction of a positioning, we understand that the recognition of the controversy or of the legitimacy of the theme in the context at stake is crucial to achieving the desired goals. Thus, starting from subsidies from the Critical Theory of Society, we characterize the process of setting up a Socio-scientific Issue among teachers as an exercise of unveiling the concrete reality, listing problematic, controversial and open to criticism aspects of Science and Technology. Thus, the Socio-scientific Issue is listed out in the group as soon as it is established a polyphonic dialogue where all participants stand, recognize the fertility of the themefor the intendededucational context and can speak of it with propriety.

Uma proposta de formação continuada de professores de ciências e matemática na interface do agir comunicativo e das questões sociocientíficas

The objective of this paper is to present a theoretical proposal for the training of teachers of mathematics and science at the interface of communicative action and socio-scientific issues. In this paper we argue for the need for a continuous training of teachers if we are to be interested in developing the scientific training of students from the public school system. To form communicatively competent students, by the end of schooling, becomes necessary the training of argumentatively competent teachers. Therefore, we believe that the theory of communicative action by Jurgen Habermas, will cooperate to this end.

Possibilidades e limitações da prática do professor na experiência com a temática energia e desenvolvimento humano no ensino de ciências

Reflections on the Movement STSE, in basic education, have pointed to the introduction of discussions involving the socio-scientific issues, as a way of organization and development of forming processes in science classes. In this sense, the research that we developed sought to bring to physics classes of basic education, the discussions surrounding the relationship between science, technology, society and environment issues related to production and access to electricity and human development. In order to interpret formative aspects of this approach was achieved through a short course. Thus, we discuss in this paper, the discourse of students and a professor of physics who participated in this short course. Therefore, we seek in discourse analysis, reflection on this practice, which has limitations such as lack of recognition of this type of training status by the students as well as possibilities represented by the establishment of training spaces that contribute to the discussion of socio-scientific issues.

Sensibilização da audição e educação sonora nos exercícios de limpeza de ouvidos: uma incursão na Educação Matemática

The teaching of acoustics has been characterized by a banking model that little contributes to the ideal training of citizens capable of understanding and acting to improve their environment soundscapes. Equally distant from the world of sound and musical culture, audio technology and acoustic environment, it is disconnected from the ever-increasing effort to raise awareness on hearing and sound education, as defended by the Canadian educator Prof. Raymond Murray Schafer. In order to provide elements for reflection on how Mathematics can be itself a language to compete in a sound education, we developed, in a dialogical and problematizing method applied to the technological and cultural world, one further research and teaching with Math students of UNEMAT in Barra do Bugres. This study pointed to the feasibility of educating consciences capable of of improving their acoustic environment, modifying the landscapes where we live, under our responsibility.

La cuestión sociocientífica del Diagnóstico preimplantación genética (DPG) como posibilidad para una comprensión social de la ciencia por parte de futuros profesores

El presente trabajo hace parte de una investigación más amplia y para efectos de este artículo se consideró la pregunta problema ¿Cuáles comprensiones sobre ciencia se van construyendo por parte de los licenciandos al abordar la polémica del Diagnóstico preimplantación genética (DPG)? Y como objetivo se planteó analizar dichas comprensiones en la perspectiva de la formación de profesores. El grupo participante correspondió a 14 estudiantes de licenciatura de una universidad colombiana que participaron de un seminario sobre la polémica del DPG, a través de lecturas de noticias de periódicos nacionales, presentaciones y debates. Algunos resultados indican comprensiones tales como la relación del desarrollo científico con aspectos éticos y la comprensión sobre la ciencia como factor de poder; las cuales posibilitan mayor entendimiento de la NdC con aspectos políticos y éticos necesarios para pensar la formación de profesores.

O tratamento de questões sociocientíficas na formação de futuros professores de ciências: possibilidades e desafios nas vozes dos licenciandos

The perspective STSE (Science-Technology-Society-Environment) was recently implemented in the training courses for science teachers in Brazil, and proposes greater coordination of scientific knowledge with subjective questions that constitute the science, enables discussion of the nature of science and its implications for social and environmental issues. The present work aims to contribute to training of science teachers that approximates the current demands of contemporary society. Having as theoretical reasons the implications of STSE Movement in science teaching, we bring some considerations on pedagogical practices of undergraduates in Biological Sciences held within its Supervised. Through content analysis of the speeches of undergraduates, we can identify contributions and limitations that treatment of socio-scientific issues (SSI) revealed in the process, putting to discuss some aspects that are tangent training teachers committed to a contextualized view of science and scientific training. It discusses, among them, the relationship theory and practice in supervised training of future teachers’ conceptions about the implications of the STSE perspective in science teaching and science teacher positioning ahead controversial themes.

HEV infection in swine from Eastern Brazilian Amazon: Evidence of co-infection by different subtypes

Hepatitis E virus (HEV) is a fecal-orally transmitted member of the genus Hepevirus that causes acute hepatitis in humans and is widely distributed throughout the world. Pigs have been reported as the main source of genotypes 3 and 4 infection to humans in non-endemic areas. To investigate HEV infection in pigs from different regions of Para state (Eastern Brazilian Amazon), we performed serological and molecular analyses of serum, fecal and liver samples from 151 adult pigs slaughtered between April and October 2010 in slaughterhouses in the metropolitan region of Belem, Para. Among the animals tested, 8.6% (13/151) were positive for anti-HEV IgG but not for anti-HEV IgM. HEV RNA was detected in 4.8% (22/453) of the samples analyzed and 9.9% (15/151) of the animals had at least one positive sample. Phylogenetic analysis showed that all sequences belonged to genotype 3 that were related to human isolates from other non-endemic regions, suggesting that the isolates had zoonotic potential. Subtypes 3c and 3f were simultaneously detected in some pigs, suggesting co-infection by more than one strain and/or the presence of a recombinant virus. These results constitute the first molecular and serologic evidence of swine HEV circulation in the Eastern Brazilian Amazon. (C) 2012 Elsevier Ltd. All rights reserved.