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Luz, câmera, ciência: uma análise crítica da representação da ciência em filmes de ficção científica
(Universidade Federal de São Carlos, 2018-07-30) Mattos, Celso Luiz; Pierson, Alice Helena Campos; https://lattes.cnpq.br/3749421379531019; https://lattes.cnpq.br/1712961992559004
This work brings the analysis of the science representation of a group of cinematographic works of the genre of science fiction. Cinema, as a cultural manifestation, conveys values and visions of the world. It is possible to imagine situations, objects, beings and diverse worlds. But in every story there is the human being interacting in the universe of the film, and this interaction has much to say. Looking at Science and the scientific activity contained in a given film makes it possible to perceive how it is being represented and what values and worldviews associated with it, in evidencing it is possible to reflect and question it. Thus, a literature review was carried out on the importance and potential of cinema in education and science fiction for science teaching. With this study it was possible to propose analyzes of four works, Gravity (2013), Operation Big Hero (2014), Ex_Machina (2015) and Lost on Mars (2015). We used the analysis tool proposed by Piassi (2007) that allowed us to identify in the works the counterfactual elements and thematic poles in relation to science perceptible in the literary genre of science fiction. When analyzing the films, it was possible to note that the identification of counterfactual elements evidences scientific phenomena and concepts, while the identification of thematic poles makes it possible to establish relations between Science, Technology and Society. In addition, the analysis instrument used has the potential to be used as a methodology in science teaching for the analysis of science fiction films. The analyzes were made in order to discuss elements that could contribute with the planning of didactic activities for the teaching of sciences that counts on cinematographic works and with a critical vision on the scientific activity. Intending to this end, a science teaching that offers new meanings about science and technology in its relations with the social, political, economic and cultural context. This study is relevant for discussing ways of analyzing science fiction films with the aim of developing a critical view of science. This study can help broaden the eyes on the nature of science and the process of scientific research for both teachers and science education.
Síntese de LiFePO4 em sistema hidrotermal assistido por micro-ondas, caracterização e testes como catodo de baterias de íons lítio
(Universidade Federal de São Carlos, 2018-07-30) Bezerra, Carlos André Gomes; Biaggio, Sonia Regina; https://lattes.cnpq.br/0418215244233120; https://lattes.cnpq.br/1696058789531459
Different routes for lithium iron phosphate (LiFePO4) synthesis were studied in a microwave-assisted hydrothermal system in order to reduce the time and temperature of synthesis in relation to the traditional methods of obtaining this compound. For the synthesis of LiFePO4 different mixtures of precursor materials were investigated maintaining the molar ratio Li: Fe: P = 3: 1: 1. In the step of time and synthesis temperature optimization, heating times of 5 to 40 min and temperatures of 100 to 200 °C were investigated. Based on the structural characterization results, by Fourier transform infrared spectroscopy and X-ray diffractometry, it was found that from 10 min at 200 °C it was possible to obtain pure and crystalline LiFePO4, with particle size of 57 to 165 nm, verified by scanning electron microscopy micrographs. Cyclic voltammetry for the five best samples showed the typical voltammetric profile of the LiFePO4 with good reversibility; three of the samples selected showed high electrochemical activity, which was reflected in good values of specific capacity. In the characterization by electrochemical impedance spectroscopy, an inversely proportional relation between total impedance and values of specific capacity was verified. The sample with the best electrochemical performance presented a value of 168 mA h g-1, at discharge rate of C/10, corresponding to 99% of the specific theoretical capacity of LiFePO4. A capacity retention of 74% was verified after 100 cycles of charge - discharge at C/2, which was related to the electrolyte contamination by water, attributed to the presence of moisture in the chamber where the electrochemical cells were assembled.
Análise térmica e energética do revestimento refratário de panelas de aço via modelos computacionais
(Universidade Federal de São Carlos, 2018-07-30) Santos, Matheus Felipe; Angélico, Ricardo Afonso; https://lattes.cnpq.br/4572583709143785; Pandolfelli, Victor Carlos; https://lattes.cnpq.br/7369376873984839; https://lattes.cnpq.br/9355348071028630
The secondary metallurgy is an energy-intensive step in the steelmaking process that requires an accurate adjustment of the composition and temperature of the molten metal during the ladle refining. In this context, the steel ladle lining plays an important role on the energy consumption of the ladle processes, as the refractory thermal properties are strictly related to the ladle ability to keep constant the molten metal temperature. Aiming to improve the energy efficiency, reducing both costs and the environmental impacts, a transient numerical analysis of the ladle processes was developed using temperature dependent refractory properties. The present work proposes a holistic view of the ladle operational cycle to help the refractory design of such installations, according to their saving energy capability. The finite element modeling (FEM) was developed using a commercial software (Abaqus) to simulate the ladle cycle (pre-heating, holding and waiting steps). The temperatures predicted by the model were compared with in situ temperature data from a steel ladle to validate the model and the comparison showed good agreement between those temperatures. The results point out how the configurations with lining insulation reduces the energy consumption, keeping the molten steel temperatures higher, although it is mostly effective on reducing the shell temperatures. The safety lining could be replaced by more advanced materials with suitable properties or had its thickness reduced for expanding the working capacity and also saving energy. The refractories for the working layer application should have low or none carbon content and advanced materials for higher savings should be investigated. Computational models could indicate possible material designs and configuration solutions for the steel and refractory industries. In general, these solutions depend on each steel plant requirements, but some trends can be highlighted for improving the steel ladle energy efficiency, considering the refractory design for avoiding heat losses.