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Condutividade elétrica da solução sólida céria-zircônia dopada com ítrio e gadolínio
(Universidade Federal de São Carlos, 2009-09-10) Antunes, Fábio Coutinho; Souza, Dulcina Maria Pinatti Ferreira de; https://lattes.cnpq.br/4100119317525940; https://lattes.cnpq.br/9066668470271550
Rare earth doped ceria has a great potential to be used as electrolyte in temperatures around 800 °C in fuel cells due to its higher electrical conductivity than YSZ. However, the reduction of Ce+4 to Ce+3 in low oxygen partial pressure has introduced limitations for using doped ceria electrolyte due to electronic conduction. Among the several ceria solid solutions, CeO2-ZrO2-Y2O3 attracts attention because its stability at temperatures around 800 °C and oxygen partial pressures up 10-18 atm. On the other hand, ceria solid solutions are very sensitive to the purity of the raw material. For these reason, it is common to find secondary phase along the grain boundary blocking the electrical conduction. For these electrolytes, impurities control the grain boundary conductivity. In this work, powders (Ce0,9-xYx)Zr0,1 and (Ce0,9-xGdx)Zr0,1 with 0.10 ≤ x ≤ 0.24 were prepared by oxides mixing. The effect of successive calcinations and the addition La2O3 was evaluated. Samples obtained by isostatic pressing, were sintered between 1450 and 1600 ° C with two hours of soaking time. Sintered samples were characterized by density measurements, X rays diffraction, scanning electron microscopy and impedance spectroscopy. Among all samples, those doped with 12 mol% of co-dopant aliovalente (Y2O3 ou Gd2O3) showed similar electrical behavior. For these samples it was observed a large increase of grain boundary electrical conductivity for calcined compositions and doped with La2O3 resulting a total electrical conductivity of 4,4x10-4 S.cm-1 at 450 °C in the same order of magnitude of electrolytes Z8Y prepared for this work. Compositions containing Y+3 and La2O3 showed higher electrolytic domain compared to the other investigated compositions.
Avaliação do grau de gelificação de formulações de PVC rígido utilizando o método de ultrassom
(Universidade Federal de São Carlos, 2009-09-10) Finocchio, Henrique; Hage Júnior, Elias; https://lattes.cnpq.br/1240692926327687; https://lattes.cnpq.br/4221003986826298
The determination of the gelation degree is an important tool for predicting the properties of final products made of rigid PVC compounds. Thus, it is evident the need of a quick and effective test method that can be applied during the manufacturing process of products for quality control. In order to attend this need the ultrasound method has been applied in this work. Four rigid PVC compounds have been prepared and tested in a torque rheometer with different temperatures and times. The samples obtained, presenting different gelation degrees, have been then compression molded to obtain cubic specimens. To quantify their gelation degree the differential scanning calorimetry (DSC) technique has been applied. These specimens have been also submitted to an ultrasound testing to get their elastic constants, including the elastic modulus (E). The values of elastic modulus obtained by ultrasound have been correlated with the gelation degree obtained by DSC. In conclusion, specimens with higher gelation degrees, in general, showed higher modulus of elasticity. Therefore, it is believed that the ultrasound method may be a promising technique for evaluating PVC compounds degree of gelation and to determine their stiffness properties.
O cinema que nos dá o que pensar em Gilles Deleuze
(Universidade Federal de São Carlos, 2009-09-10) Oliveira, Claudia Silene Pereira de; Marques, Silene Torres; https://lattes.cnpq.br/4822141288006918; https://lattes.cnpq.br/9654361092283589
SADP: arquitetura de sites dirigida por personalização
(Universidade Federal de São Carlos, 2009-09-10) Blanco, Juliano Zanuzzio; Prado, Antonio Francisco do; https://lattes.cnpq.br/2668568143800755; https://lattes.cnpq.br/7759806751523441
Web sites in different areas are accessed by users with the many purposes. Several strategies have been developed and employed to improve and facilitate website access and navigation. Among these strategies there are those used to grant competitive advantages over concurrent sites, based on services of content personalization. Today, with the growth of computer networks and the emergence of ubiquitous computing, this personalization must take into account that the content of the sites can also be accessed through mobile devices. Motivated by these ideas, in this project it was developed a process in which site architectures are driven by personalization and personalized content is delivered to site users. This process, called SADP (Site Personalization by Driven Architecture), is based not only on navigation history and preferences expressed or detected by the users, but also on context information, device and network types and the site content itself. The SADP uses profiles contain information about user preferences, networks and devices used to site access. The information used to build profiles are obtained through implicit metrics, and treated using a Fuzzy Ontology. A module of Fuzzy Inference over Ontology is used to extend the user preferences. A framework for content adaptation is used to generate a site architecture based on profiles. The differential of the SADP process is that it drives the architecture of site content pages aiming to provide personalized services to the users.
Tecendo a política. Itinerários de participação política de mulheres em movimentos sociais contemporâneos na Argentina
(Universidade Federal de São Carlos, 2009-09-10) Bogado, Adriana Marcela; Silva, Maria Aparecida de Moraes; https://lattes.cnpq.br/6792025643983370; https://lattes.cnpq.br/7628617298030269
This thesis is dedicated to the study of women‟s political participation in contemporary social movements in Argentina, by the means of the reconstruction of their course of life, from the perspective of their experiences and memories. In a context of crisis, as consequence of the neoliberal model implemented, the social movements present themselves as key areas of political struggle and, at the same time, as spaces of construction of cultural, social, political and economic alternatives. In relation with these organizations, the paths of political participation are developed and/or enhanced, however, we identify a process in which women participation becomes invisible. In this research we analyzed the mentioned participation with the aim to understand the factors and practices that generate exclusion and that which encourages its development, identifying the existence of limits and the different possibilities for women‟s political activities. We also situated the political participation within the theoretical and methodological universe of empowerment and gender relationships, in order to contribute to understand women‟s situation in the current social, political, economic and cultural panorama. The field work was developed with participants and leaders of Movimiento de Mujeres en Lucha (MML), in General Roca (Río Negro) and Rosario (Santa Fe); and with participants and leaders of the first pickets in the rural areas of Argentina and in the state of Buenos Aires, the Corriente Clasista Combativa (CCC, Zona Norte). Using the methodology of Oral History and the Participant Observation we rebuild the course of life of six women, presented in the form of biographical portraits (portraits). Each one of the portraits describes the processes of political engagement, the current involvement and future prospects, pointing out the connections with family, social and professional dimensions. Although feeling "forced" to leave in order to fight, these women have found recognition in the struggle. They also strengthened their networks of sociability, found courage to draw their own process of empowerment and they are still learning about politics in the dialectic of their course of life.