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Preparação e caracterização das propriedades luminescentes de blendas de poli(3-ácidotiofenoacético) com acetato de celulose ou poli(vinil álcool)
(Universidade Federal de São Carlos, 2010-11-19) Bergamaski, Franciele de Oliveira Freitas; Souza, Ernesto Chaves Pereira de; https://lattes.cnpq.br/1505400360366643; https://lattes.cnpq.br/1192013631012905
We have studied the optical properties of Poly(3-Thiopheneacetic Acid) (PTAA) by absorption, emission, and infrared measurements. We have observed, on the contrary of what broadly reported in the literature, that the intensity of the PTAA luminescence increased with time exposition of the Laser beam. The results have been shown that luminescence was highly dependent of the power of Laser beam excitation and of the polymeric (blends) film thickness. To evaluate the chemical changes in the course of luminescence increasing, absorption measurements in the infrared range were done. A decrease in the band of 1560 cm-1 was observed after Laser beam irradiation, what could be related with a decrease in the number of C=C bonds, and it is a possible explanation for the luminescence intensification. The PTAA photoluminescence was studied under high vacuum showing that the increase of luminescence was not dependent of oxygen presence in the polymeric film. Besides, we have done photoluminescence measurements at temperature of 10 K and compared with that at room temperature, 298 K. In the irradiation of the films at 10 K it was observed a suppressing effect that could be related to conformational changes in the polymer structure. Finally, we have measured the time resolved photoluminescence (TRPL) of PTAA and AC/PTAA blends in picoseconds in two temperatures regime. It was investigated the TRPL transients for different samples of PTAA in several solvents and for blends with cellulose acetate (AC) or poly(vinyl alcohol) (PVA). In all samples (the pure polymer and in the blends) the PL transients have presented behavior mono- and biexponentials. However, the mono-exponential model, in most cases, was not sufficient to describe adequately all PL decays. So, it was used a function in the form of two exponentials sum.
A caracterização da produção de materiais didáticoeducativos audiovisuais para educação superior a distância na UFSCar
(Universidade Federal de São Carlos, 2010-11-19) Montanaro, Paulo Roberto; Santiago, Glauber Lúcio Alves; https://lattes.cnpq.br/9385173410103898; https://lattes.cnpq.br/9722367900588242
This survey aims to collect data on the production of audiovisual content intended for undergraduate courses in e-learning mode. Mapped Thus, each of the elements produced, their production system and the actors who work directly or indirectly in the construction of these materials. Therefore, we attempted to trace a brief history of the development of several other audiovisual productions over the years that have passed, so that they know the way political, aesthetic and linguistic achievements they had so far. Likewise, it also draws a picture on the understanding of the system applied in the university, through the project called Universidade Aberta do Brasil, known by the acronym UAB, as well as its structure around a specific department, the Secretaria Geral de Educação a Distância, or SEaD, within the Universidade Federal de São Carlos - UFSCar - which is also critical to understand that one can macroscopically pedagogical issues, techniques and systematic material produced there. Thus, the creation of an audiovisual team within the structure of this department is essential for the project shows that the process of teaching and learning for the proposed project, since the use of multiple media is the basic assumption in this system. The evolution of team formation, their training and the duties performed by each of its elements are extremely important for understanding the intentions of undergraduate courses created and there is part of this research, as well as developments in its production process, procedures and results. That said, means the audiovisual production focused on e-learning as part of a larger system and complex content and instructional materials were defined and delimited by the collaboration between the different actors involved in the process, as well as limitations and technical characteristics of the process, production time and internal policies of the political-pedagogical project of the institution and the course as a whole.
Transformações na matéria orgânica nos sedimentos e águas eutrofizados da Represa Ibirité (Ibirité-Sarzedo, MG) tratados com nitrato de cálcio em microcosmos
(Universidade Federal de São Carlos, 2010-11-19) Colzato, Marina; Mozeto, Antonio Aparecido; https://lattes.cnpq.br/6594211224864538; https://lattes.cnpq.br/1359688001544183
Due to the growing concern with the environment and the welfare of future generations the search for the restoration of degraded areas and the reestablishment of equilibrium between the anthropogenic and natural environments are nowadays highlighted. The Ibirité Reservoir (Ibirité-Sarzedo, MG) is an example of water body impacted by the disorganized urbanization and strong industrial development in the metropolitan Belo Horizonte, MG, SE Brazil. The reservoir, built by the REGAP-Petrobras in the sixties to supply water to its industrial processes, is a eutrophic water body due to the continuous contribution of urban sewage (external loading) and the consequent internal loading of nutrients (mainly of phosphorus), the primary element responsible for the eutrophication process. Among the existing technologies for the treatment of eutrophic sediment focusing on the P immobilization is the artificial supply of nitrate as an electron acceptor to the stimulation of the natural denitrification process. In this stimulation process, the different geochemical forms of reduced iron are oxidized to iron (III) oxi-hidroxides that adsorbs the phosphorus present in the sediment pore water. In addition to that, the metallic sulfides and the organic matter are oxidized as well. This work aimed at the development of laboratory experiments in a bench scale (microcosms) in which sediments and water of the Ibirité reservoir were treated with nitrate addition in order to evaluate the organic matter transformations from caused this treatment. The results indicate that there was, in the treatment microcosms, an increase in the redox potential, an almost complete abatement of the acid volatile sulfide (AVS) of the sediments, and a significant reduction of available phosphorus in the water. The UVvis spectroscopy indicated differences in the spectral profiles between the control and treatment microcosms, but uniform trends along the experiment were not identified. The elemental analysis showed agreement with the results of AVS and nitrogen species in sediment pore water data, with the reduction of sulphur and nitrogen contents.