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Exergia e serviços ecossistêmicos de duas bacias hidrográficas do estado de São Paulo, Brasil
(Universidade Federal de São Carlos, 2016-09-23) Periotto, Natalia Andricioli; Tundisi, José Galizia; https://lattes.cnpq.br/5730659239785432; https://lattes.cnpq.br/1566592373309531
Eco-exergy is an innovative approach to evaluate ecosystem services, since it encompasses all possible ecosystem functions and processes in a single estimate. In this study, eco-exergy values of wetlands and native vegetation areas of Jacaré-Guaçu and Jacaré-Pepira Watersheds were estimated. The obtained values (average of 3,389 GJ.ha.ano-1, wetlands; average of 5,810 GJ.ha.ano- 1, native vegetation) are consistent with reference values showed by Jørgensen [Jørgensen, S.E. 2010. Ecosystem services, sustainability and thermodynamic indicators. Ecological Complexity, vol. 7, p. 311-313]. From a perspective of the ecoexergy concept, management practices of native vegetation and wetlands in both watersheds should consider not only quantity of vegetation conserved or restored, but also biodiversity of vegetation species. Consequently, multiple ecosystems services would be guaranteed for human well-being and for selfregulation of these ecosystems.
Investigação da corrosão do aço carbono AISI 1020 em soluções de NaCl utilizando microscopia óptica in situ
(Universidade Federal de São Carlos, 2016-09-23) Santos, Rapher Donizete Moreira; Souza, Ernesto Chaves Pereira de; https://lattes.cnpq.br/1505400360366643; https://lattes.cnpq.br/1113005994646562
According to recent information from the World Corrosion Organization, annually, approximately 2.2 trillion of global GDP is spent on corrosion-related damage. These expenses are almost the GDP of the seventh world economy in 2015, India. Corrosion-related problems occur in different materials and in various industrial sectors such as automobile, shipbuilding, petrochemical, oil companies. One important source of corrosion in the industry is presence of chloride in aqueous solutions. This work presents a study of the corrosion of carbon steel AISI 1020 in aqueous NaCl solution from 0.1 and 0.25 mol/L at temperatures of 25° and 45° C. The steel corrosion was investigated using open circuit potential measurements (Eoc), and polarization curves (PC) coupled to optical microscopy in situ. Thus, the influence of these two factors was evaluated by the interpretation of the effects using a factorial design. From the images of the temporal series obtained by optical microscopy in situ carried during the polarization curves, it was possible to analyze the behavior and characteristics of the corrosion process, such as the average corrosion potential, corrosion rate, eroded fraction, and quantifying the maximum diameter of the pits. Through the obtained results, it is possible to observe the direct influence of concentration and temperature of the corrosion process in the carbon steel AISI 1020, with the increase in the amount of corroded pits and the eroded fraction. It is possible to observe that the corrosion process starts by individual pits, which is converted to mass propagated pits known as pit colony. The development of individual pits was relatively fast, with less than 200 seconds and a maximum diameter up to 600 μm containing area of around 2 x 10^5 μm^2.