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História da educação agrícola do sul de Minas Gerais : a Escola Agrícola de Muzambinho (1948-1985)
(Universidade Federal de São Carlos, 2016-05-24) Vieira, Lívia Carolina; Ferreira Junior, Amarilio; https://lattes.cnpq.br/0748545841167046; https://lattes.cnpq.br/0765100136177086
This research lies in the field of history of school institutions and has as its object of study the Agricultural School of Muzambinho, with the objective of analyzing the process of is creation and the formation offered to students. This study also assists in the understanding of the goals and directions of the institutions of agricultural education in Southern Minas Gerais, important region for agricultural production in the time frame chosen for the analysis: 1948 to 1985.The choice of the period has since the early initiatives for school creation until the end of the period of military dictatorship in Brazil to analyze the implementation of the model school - farm, a result of the relations between the United States and Brazil. The primary documents were the main basis of research, among them the reports of management; student identification cards; enrollment maps; academic contents lists; school subjects lists and table of content; letters with requests from students and teachers to the school secretary; newspapers; laws and decrees relating to the period, opinions, resolutions, messages of the governors, reports of the President of the Province; pictures of the school and the city. Were also carried out interviews with former students and school personnel. The method chosen to make such analyzes is dialectical and historical materialism, which investigates the intimate connection between the way in which society produces its material existence and the school institution that creates. As a reference we chose authors who investigate the history of school institutions as Magalhães (1998), Saviani (2007), Araújo (2007) (2000) and Buffa; Nosela (2013). The results indicated the connection of the school with the need for training of rural workers and the modernization of the field, driven by the influence of the United States after 1960. These actions promote changes in national production and the agricultural education based on the implementation of the school-farm model.
Deposição de nanocristais coloidais: da síntese à aplicação na fotoeletroquímica da oxidação da água
(Universidade Federal de São Carlos, 2016-05-24) Gonçalves, Ricardo Henrique; Mallouk, Thomas E.; Leite, Edson Roberto; https://lattes.cnpq.br/1025598529469393; https://lattes.cnpq.br/2385127856921005
An excellent and potentially efficient route towards storing solar energy is to convert light into chemical energy in the form of chemical bonds, which is a form of artificial photosynthesis. Considering the abundance of H2O on the planet, water splitting is a natural pathway for artificial photosynthesis. Hematite is an n-type semiconductor with high chemical stability in alkaline media and promising material for photoelectrochemical water splitting. This Thesis describes critical parameters involved in the Colloidal Nanocrystals Deposition (CND) process to produce hematite photoanodes with high efficiency for solar-to-hydrogen conversion. In chapter 2, a fundamental study reveals that the interface solid-solid is a parameter that has strong influence on the performance of the photoanode. The gap between the FTO substrate and hematite thin film was observed by HRTEM image and it can be overcome during a sintering stage. In the same chapter, the solid-solid interface analysis was correlated with the photoresponse and it has showed that hematite thin film treated at 1000 oC also improved the response of this photoande. This result was explained based on the grain growth and associated with the mass distribution on the FTO surface. In chapter 3, the CND process was improved using the magnet to assist the nanocrystals deposition and also oxidation of magnetite (Fe3O4) to maghemite (γ- Fe2O3) to avoid the presence of Fe2+. In this approach, Sn4+ was used as a doping element and has showed a significant improve on the photoresponse of the hematite. The STEM-EDS analysis has showed that Sn has ability to segregate on the hematite grain boundary during sintering process, blocking grain growth process. The results showed in chapter 4 were essential to understand the thickness effect on the photocurrent of thin film produced by CND process. In this case, changing the nanocrystals concentration has direct effect on the thickness of the hematite thin film. The FTO roughness also showed significant influence on the orientation of hematite grain along the direction <110>. In this study, it was possible to calculate the maximum theoretical efficiency for the hematite photoanode obtained by this method. The thickness control and homogeneity of the thin film give a great perspective for technological application of this process. The in situ heating TEM demonstrated that nanocrystals has abnormal grain growth and also a superplastic phenomenon, as revealed in chapter 5. In this chapter, Sn was deposited on γ-Fe2O3 impeding atom dislocation on the grain boundary and consequently inhibits the growth process. This experiment was an approach to simulate the sintering process performed in the CND process. The electrocatalyst described in chapter 6, showed low overpotential for OER. The strategy to use a Prussian blue analogue to deposit a thin layer of nickel-iron hexacyanoferrate and convert into oxyhydroxide achieved excellent homogeneity and low overpotential for OER. This result is comparable with IrO2 and RuO2 that are electrocatalysts with high electrochemical performance. Catalyst supports were also evaluated, such as FTO, palladium and PGS. The PGS substrate showed an excellent performance as catalytic support for OER, with similar results of palladium foil.
Mapeamento geoestatístico tridimensional do teor de umidade e caracterização energética em pilhas de cavacos de madeira
(Universidade Federal de São Carlos, 2016-05-24) Valentim, Larissa Benassi; Pádua, Franciane Andrade de; https://lattes.cnpq.br/2945447364979913; https://lattes.cnpq.br/6654011118796928
The execution of this work aimed at the use of geostatistics to predict the spatial pattern of variation of moisture content in piles of eucalyptus wood chips intended for energy production to generate subsidies to adequate sampling and handling of the material. For this, piles wood chips were installed for evaluation in three different storage periods, these rings being made by the newly cut material in seven, thirty and sixty days of storage. Sampling occurred in both axial positions (top, middle and base) side, so that all samples were georeferenced in relation to the distance from the ground and the center of the pile. The moisture content of the wood chips in each sample point was determined by gravimetric method recommended by NBR 14929 (ABNT, 2003). In addition, samples were subjected to analysis bulk density, particle size distribution, chemical analysis and determination of its calorific value, aiming at energy material characterization. The humidity values were submitted to geostatistical analysis and kriging. Our results confirmed the spatial dependence of the moisture content over the piles stored at seven and thirty days, confirming that the use of geostatistics is a useful tool to support the creation of sampling protocols and assist moisture content distribution studies over the pile. The effect of rain was crucial to reduce the spatial dependence on pile sixty days of storage, indicating that the wood chips stored in the form of piles are subject to wetting even in inner parts of the pile. In general, Eucalyptus grandis wood chips showed satisfactory technological characteristics for energy production.