Papers by Author: Domingos Barbosa

Abstract: An analytical method, using High Performance Liquid Chromatography, was developed for quantification of atrazine in extracts obtained by supercritical extraction of contaminated soils. The method shows good linearity, for concentrations ranging from 0.1 mg/L to 200 mg/L, and reproducibility, giving deviations lower than 2%. The recovery of atrazine by SCE was in the range of 96 to 98%.

Abstract: In this work the use of Membrane Bioreactors to treat leachate effluents is discussed. The problem of membrane fouling is addressed, and some of the efforts being done to overcome this problem presented. The process optimization requires the reduction of other parameters, some directly related to mass transfer, such as the total amount of solids, the total dissolved solids and the total suspended solids. The preliminary results obtained show the high potential of this technique for the treatment of leachates, mainly for the reduction of solids in leachate streams.

Abstract: Research and applications of magnetically stabilized and fluidized beds begun several decades ago, and have maintained their rate of interest during all these years. During last years their applications was diversified, and the application of these beds in the processing of biological materials and in environmental issues has nowadays focused the main attention within this area. In this work we present a brief review of magnetically fluidized and stabilized beds, mainly concerning their theoretical background, heat and mass transfer topics, some industrial and laboratorial setups and applications.

Abstract: Constructing a new device we had to design some vapour-cooled current leads. This current leads are made of Low-Tc material connected with copper wires and some parts of High-Tc material. Its design is calculated keeping in mind the heat transfer by diffusion to a vapour-cooled stream that surrounds the conductive materials. The design and the calculations performed to achieve it, and also the background theory of the heat diffusion applied in this part of the device will be described.