L. de Oliveira

Solar photocatalytic water detoxification of paper mill effluents

To implement solar photocatalytic water detoxification in industrial processes, problems have to be identified. The effluents from paper mills contain non-biodegradable substances like polyphenolic polymer lignin. Photocatalysis is a suitable method to degrade this class of substances. Especially in good solar regions, like Brazil, solar radiation should be ideally used for that process. The German Aerospace Center and the Federal University of Uberlândia-MG, Brazil are cooperating in a project funded by the German International Bureau of the Federal Ministry of Education and Science and CNPq, Brazil to implement solar photocatalysis in the treatment of paper mill effluents. Therefore, the following tasks are worked on: model compounds for the contaminants have been identified and compared to the real effluents. Different photocatalysts and oxidizing agents were tested to shape the degradation process for use in an industrial application. Tests were carried out in lamp reactors as well as in solar reactors to determine the influence of the reactor on the degradation. The kinetic of the degradation was also determined. The test results have shown that the non-biodegradable substances can be very effectively degraded by photocatalytic treatment. Especially in solar reactors like the CPC type reactor, degradation takes place very fast. Total mineralization of the contaminants can be reached. The paper describes the project as well as the test results and will provide an outlook to the implementation of solar photocatalytic detoxification technology in Brazil.

The SOAR integral field unit spectrograph optical design and IFU implementation

SIFS is a lenslet/fiber Integral Field Unit Spectrograph which has just been delivered to the SOAR 4.1m telescope in Chile. The instrument was designed and constructed by the National Laboratory of Astrophysics (MCT/LNA) in collaboration with the Department of Astronomy of the Institute of Astronomy, Geophysics and Atmospheric Sciences of the University of Sao Paulo (IAG/USP). It is designed to operate at both the raw Nasmyth and the SAM (the SOAR Adaptive Optics Module) which delivers GLAO-corrected images in optical wave-bands longward of 500nm. The lenslets have a 1mm pitch feeding a set of 1,300 fibres in a 26-by-50 format. Sets of deployable fore-optics convert the f/16.5 input beam to give samplings between ~0.1 and 0.3 arcsec. The fiber output is in the form of a curved, pupil-centric, long-slit which is fed into a bench-mounted spectrograph. An off-axis Maksutov collimates the beam onto a set of VPH gratings and thence imaged by an f/3 refractive camera onto a 2-by-1 mosaic of 2k-by-4k E2V CCDs. The camera is articulated over a >90 deg. angle to allow the grating/camera combination to operate in a transmission Littrow configuration. The wavelength range is limited by the CCDs to the 350 to 1000nm range with spectral resolution maxima of ~20,000. The paper will review the optical design of the spectrograph and the methods used to fabricate the lenslet/fiber IFU.

Solar-Driven Continuous Methane Reforming Reactor

In this paper we describe a novel receiver-reactor concept for continuous thermochemical fuel production powered by concentrated solar energy. The novelty of the receiver-reactor is a dual use of solar power. While half of the receiver-reactor is used to conduct an endothermic reaction producing solar fuels, the other half of the reactor has a heat exchanger characteristic. Through this heat exchanger part, energy can be transferred to a heat storage during daytime operation. During nighttime operation, the energy from the storage can be brought back into the reactor.

Chemical Composition of Essential Oil from Leaves of Stemodia foliosa Growing Wild in a Fragment of the Atlantic Forest of Pernambuco, Brazil

The genus Stemodia Linnaeus (Scrophulariaceae) comprises approximately 50 species with pantropical distribution in the Americas, Africa, Asia, and Australia [1]. This genus was transferred to the family Plantaginaceae based on phylogenetic studies involving molecular data [2]. Plants of this family are herbs and bushes that grow easily in open areas with high moisture content in the soil. Among the 30 species found in the Americas, 14 occur in Brazil, with broad distribution in the northeastern region of the country [1]. In the state of Pernambuco, the common name for Stemodia foliosa is meladinha, and this plant is used in rural communities as a folk remedy for the treatment of respiratory tract infections [3]. A previous chemical investigation of the ethanol extract of the shoots of S. foliosa revealed the presence of esters [4] and diterpenes of the class of labdanes, which demonstrated important antimicrobial activity against Mycobacteirum tuberculosis [5], thereby confirming the property attributed to this plant by practitioners of folk medicine. However, no studies have yet been conducted on the chemical characterization of the essential oil from S. foliosa. As part of an ongoing chemical investigation into essential oils from aromatic plants that occur in the Atlantic Forest in the state of Pernambuco, Brazil, the aim of this work was to determine the chemical composition of the essential oil from the leaves of S. foliosa.