Multi-scale Visualization of Remote Sensing and Topographic Data of the Amazon Rain Forest

PETROBRAS (the Brazilian national oil company) built a pipeline to transport crude oil from the Urucu River region to a terminal in the vicinities of Coari, a city located in the right margin of the Solimoes River. The oil is then shipped by tankers to another terminal in Manaus, capital city of the Amazonas state. At the city of Coari, changes in water level between dry and wet seasons reach up to 14 meters. This strong seasonal character of the Amazonian climate gives rise to four distinct scenarios in the annual hydrological cycle: low water, high water, receding water, and rising water. These scenarios constitute the main reference for the definition of oil spill response planning in the region, since flooded forests and flooded vegetation are the most sensitive fluvial environments to oil spills. This study focuses on improving information about oil spill environmental sensitivity in Western Amazon by using 3D visualization techniques to help the analysis and interpretation of remote sensing and digital topographic data, as follows: (a) 1995 low flood and 1996 high flood JERS-1 SAR mosaics, band LHH, 100m pixel; (b) 2000 low flood and 2001 high flood RADARSAT-1 W1 images, band CHH, 30m pixel; (c) 2002 high flood airborne SAR images from the SIVAM project (System for Surveillance of the Amazon), band LHH, 3m pixel and band XHH, 6m pixel; (d) GTOPO30 digital elevation model, 30\u27 resolution; (e) Digital elevation model derived from topographic information acquired during seismic surveys, 25m resolution; (f) panoramic views obtained from low altitude helicopter flights. The methodology applied includes image processing, cartographic conversion and generation of value-added product using 3D visualization. A semivariogram textural classification was applied to the SAR images in order to identify areas of flooded forest and flooded vegetation. The digital elevation models were color shaded to highlight subtle topographic features. Both datasets were then converted to the same cartographic projection and inserted into the Fledermaus 3D visualization environment. 3D visualization proved to be an important aid in understanding the spatial distribution pattern of the environmentally sensitive vegetation cover. The dynamics of the hydrological cycle was depicted in a basin-wide scale, revealing new geomorphic information relevant to assess the environmental risk of oil spills. Results demonstrate that pipelines constitute an environmentally saver option for oil transportation in the region when compared to fluvial tanker routes

Engineering Analysis with Boundary Elements

Texto completo: acesso restrito. p. 1296–1300Stress concentration is one of the most common problems related to automotive components and numerical analysis can be of great interest to deal with such problems. The boundary element method (BEM) is a technique which can be used in stress analysis and it is specifically applied to the design of a car component here. This work presents the efficacy of the application of a procedure based on BEM sub-model for stress analysis in a proposed design change of a front bumper fascia. The results confirm the consistency of the proposed procedure compared to the finite element method (FEM), a consolidated method for stress analysis in the automotive industry

Journal of Supercritical Fluids

Texto completo: acesso restrito. p. 1-8In this work a new method to predict upper crossover pressure based on equations of state is developed and applied to systems containing supercritical CO2 and Annatto (Bixa orellana) pigments. The calculation of the solubility of bixin in supercritical carbon dioxide is done using the Peng–Robinson–LCVM–UNIFAC equation of state and the effect of any uncertainty of some solid pure component properties on the upper crossover pressure is also investigated. The calculation of the solubility of norbixin in supercritical CO2 is also done but in a completely predictive way using only solubility parameter data and group contribution since no experimental data of solubility is available. For both systems pure component parameters are initially estimated by group contribution and subsequently tuned by the model. It is also shown that the slope of sublimation pressure curve plays a major role in the accuracy of the upper crossover pressure determination. Furthermore, the present method can be used for upper crossover pressure analysis regardless of the equation of state and mixing rules adopted to calculate the fugacity coefficient of solid solute in the fluid phase. The results for solubility and crossover pressure calculated with this method are in good agreement with experimental data for CO2–bixin available in literature. The method described here can be useful to any solid–fluid system of interest in supercritical fluid extraction process synthesis

Journal of Supercritical Fluids

Texto completo: acesso restrito. p.107–117The research reported in this study is focused on modeling high-pressure phase behavior for CO2–limonene and CO2–linalool. A modified Peng–Robinson equation of state was applied to calculate vapor–liquid equilibrium using five different mixing rules obtained by incorporating activity coefficient models. The methodologies proposed by Heidemann–Kokal, Wong–Sandler and LCVM were used coupled with NRTL, UNIQUAC and UNIFAC models. A comparative analysis of the generated models was done for the binary systems and the best model was chosen to describe phase behavior of the system CO2–limonene–linalool. An isothermal flash calculation was applied to investigate selectivity and yield simultaneously for this ternary system in order to understand better the process parameters governing supercritical CO2 deterpenation of citrus peel oil. The results showed that to obtain good separation between limonene and linalool at 50°C and pressures from 80 to 90 bar a high CO2/oil ratio is needed. As this ratio decreases, the process can be operated at 60 and 70°C over the same pressure range with equivalent performance

Fuel Processing Technology

Texto completo. Acesso restrito. p. 102–107The transesterification of waste frying oil (WFO) with methanol and ethanol was studied in a batch reactor using a zinc aluminate catalyst prepared by the combustion reaction method. The reaction runs were carried out for 2 hours, using alcohol:oil molar ratio of 40:1, temperature range of 60–200 °C, catalyst ratio of 1–10% wt., under 700 rpm stirring. The catalyst was characterized by XRD, EDX, TG, FTIR, N2 physisorption, NH3- and CO2-TPD. The catalyst showed a normal spinel structure and acid character (Lewis acid), in spite of the presence of both strong acid and base sites. Methyl and ethyl esters yields higher than 95% were obtained at 150 and 200 °C and the catalyst was recovered and reused in 3 reaction cycles, without significant loss of activity.Salvado