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Especiação redox de crômio em amostras de solos contaminados
(Universidade Federal de São Carlos, 2012-03-21) Canevari, Natália Tostes; Pereira Filho, Edenir Rodrigues; https://lattes.cnpq.br/3394181280355442; https://lattes.cnpq.br/7309684456090159
Chromium and its compounds are employed in various industrial processes, and these activities are responsible for the disposal of significant amounts of materials containing this element in the environment. Due to the known toxic feature of Cr(VI) in biological systems, the determination of chromium species has acquired great importance in environmental chemistry. In this study three analytical strategies were combined, X-ray absorption spectroscopy, flame atomic absorption spectrometry and UV-Vis molecular absorption spectrophotometry, in order to identify and determine Cr(III) and (VI) in contaminated soil samples. The samples were collected around the Comandante Ferraz Antarctic Station, a Brazilian scientific station in Antarctica. For the pseudototal chromium analysis, acid digestion was employed for sample preparation and determinations were performed using a flame atomic absorption spectrometer. Na2CO3 0.28 mol L-1 - NaOH 0.5 mol L-1 extractor solution and heating were used for Cr(VI) extraction in the samples, and preliminary identification of this specie was performed using XANES and EXAFS techniques at the Brazilian Synchrotron Light Laboratory. For Cr(VI) determination, NaOH 0.1 mol L-1 and heating were employed for the extraction of the specie, and determinations were based on the reaction of Cr(VI) with the colorimetric reagent diphenylcarbazide in acid medium, using a flow injection analysis system coupled to a molecular absorption spectrophotometer. The quantification of Cr(III) was carried out by subtraction between the pseudototal chromium concentration and Cr(VI) concentration. Results obtained were compared with those calculated from the determination of Cr(VI) with diphenylcarbazide in batch mode. Chromium (VI) concentrations determined in soil samples using both methods were discordant, and these differences were originated from problems occurred in the developed flow injection analysis system.
Transformações na indústria sucroalcooleira brasileira no início do século XXI: das famílias aos acionistas
(Universidade Federal de São Carlos, 2012-03-21) Mundo Neto, Martin; Grün, Roberto; https://lattes.cnpq.br/6028266827740491; https://lattes.cnpq.br/8118489647547095
Over the last years, many companies have joined the Brazilian capital market. This movement would be said to have unfolded the institutional changes that occurred in Brazil during the last decade of the twentieth century, especially, the privatization process of a set of large Brazilian State-owned enterprises, the new law of public corporations and the new rules adopted in the Sao Paulo Stock Exchange Market. Concomitantly, the Brazilian sugarcane industry has undergone several transformations. If until the decade of 1990, the hegemony was characterized by national groups under the control of traditional families, the intensification of the mergers and acquisitions operations with a significant participation of international investors has, however, modified this space. The empirical data point out the capital concentration in the industry, notably by means of mergers and acquisitions as well as the business restructuring anchored on the notion of shareholder value and corporate governance. This process could also be understood as part of the financialization process which has been diffused in the Brazilian society. Here, our focus will be highlighted on the participation of the representatives from the risk-capital industry, notably the BNDES Participations, a subsidiary of the National Development Bank (BNDES), which has played a major role in the diffusion of a new control conception for the Brazilian industries in general. Among the main Sugarcane groups considered, a significant increase could be observed on the part of international investors as well as huge national economic groups that were not previously present in the industry.
O conceito de desenvolvimento segundo Hegel: a progressão da consciência
(Universidade Federal de São Carlos, 2012-03-21) Malinski, Tania Alexandra; Santos, Paulo Roberto Licht dos; https://lattes.cnpq.br/1681044854219924
The present thesis defends that Hegel´s dialectic can be understood as a process of development, both from the standpoint of pure reason and from a perspective based on historical and political factors. The dialectic of the concept is a development of the consciousness of being with relation to an object so as to comprehend the universal content of the object. The preservation of what is in opposition in the dialectical synthesis is the nucleus of the idea of development and what gives it a positive, constructive and directional character as philosophical and historical process. From a strictly rational point of view, development is the progression of consciousness. From a historical perspective, development is the progressive manifestation of spirit, or Geist. Both means of development consolidate themselves with the enunciation of the concept, which envelops an internal and subjective determination as well as a normative element. The philosophical law contained in the concept reveals its intrinsic value and its comprehension becomes a constitutive part of being. The determination in terms of rule of law and moral values is the absolute determination towards which is driven the national spirit.
Metátese de fechamento de anéis de derivados da R-(-)- Carvona
(Universidade Federal de São Carlos, 2012-03-21) Desiderá, André Luiz; Brocksom, Timothy John; https://lattes.cnpq.br/7055452150201902; https://lattes.cnpq.br/4748593313421958
In this work was developed a new synthetic route to obtain cicloeptenone not conjugated selectively, through a faster and simpler methodology, and in accordance with good practices of green chemistry. By experimental techniques of nuclear magnetic ressonance (NMR) were assigned the stereochemistry of two diastereoisomeric pairs. Intermediate compounds were synthesized for the synthesis of sesquiterpenes guaianes (a), nor-guaianes (b) and pseudo-guaianes (c). To react the mono-allylated to form bis-alilados products with and without replacement, for further formation of compounds containing ring-type spiro[4.6]undecane. It was also developed a new methodology for formation of tensioned spiro rings (d) derivatives from (R)-carvone, using the reaction of ring closure metathesis. Using this methodology allylation, obtained was a precursor for a new way to reach the system bicyclo [5.3.0] decane (e). In total, 18 compounds were synthesized, of which 7 are unpublished.