Potential of municipal solid waste (MSW) as a source of energy in São Paulo: Its impact on CO2 balance

Energy generation is needed in São Paulo and MSW represents a promising alternative, although it is more expensive than hydroelectric power. About 14 900 t/day of MSW is generated, of which 8433 t/day is domestic and commercial MSW. From this amount, 1800 t will be destined to generate 30 MW of power. The eco-balance of CO2 has been considered for incineration and recycling. The recycling program of plastics, metals, paper and glass would represent a significant reduction in energy and CO2 emission. The total CO2 released is 3.34 x 10(5) t/yr without recycling. and is 1.25 x 10(5) t/yr with a recycling program. Most of the CO2 comes from plastics and paper production. Economic aspects could probably favor Incineration with energy production as the best option. (C) 1998 Published by Elsevier B.V. Ltd. All rights reserved.

The generation and utilization of a cancer-oriented representation of the human transcriptome by using expressed sequence tags

Whereas genome sequencing defines the genetic potential of an organism, transcript sequencing defines the utilization of this potential and links the genome with most areas of biology. To exploit the information within the human genome in the fight against cancer, we have deposited some two million expressed sequence tags (ESTs) from human tumors and their corresponding normal tissues in the public databases. The data currently define approximate to23,500 genes, of which only approximate to1,250 are still represented only by ESTs. Examination of the EST coverage of known cancer-related (CR) genes reveals that <1% do not have corresponding ESTs, indicating that the representation of genes associated with commonly studied tumors is high. The careful recording of the origin of all ESTs we have produced has enabled detailed definition of where the genes they represent are expressed in the human body. More than 100,000 ESTs are available for seven tissues, indicating a surprising variability of gene usage that has led to the discovery of a significant number of genes with restricted expression, and that may thus be therapeutically useful. The ESTs also reveal novel nonsynonymous germline variants (although the one-pass nature of the data necessitates careful validation) and many alternatively spliced transcripts. Although widely exploited by the scientific community, vindicating our totally open source policy, the EST data generated still provide extensive information that remains to be systematically explored, and that may further facilitate progress toward both the understanding and treatment of human cancers.

Conservation genetics of the endangered Pampas deer (Ozotoceros bezoarticus)

The Pampas deer (Ozotoceros bezoarticus L. 1758) is the most endangered neotropical cervid, and in the past occupied a wide range of open habitats including grassland, pampas, savanna, and cerrado (Brazil) from 5 degrees to 41 degrees S. To better understand the effect of habitat fragmentation on gene flow and genetic variation, and to uncover genetic units for conservation, we examined DNA sequences from the mitochondrial control region of 54 individuals from six localities distributed throughout the present geographical range of the Pampas deer. Our results suggest that the control region of the Pampas deer is one of the most polymorphic of any mammal. This remarkably high variability probably reflects large historic population sizes of millions of individuals in contrast to numbers of fewer than 80 000 today. Gene flow between populations is generally close to one migrant per generation and, with the exception of two populations from Argentina, all populations are significantly differentiated. The degree of gene flow was correlated with geographical distance between populations, a result consistent with limited dispersal being the primary determinant of genetic differentiation between populations. The molecular genetic results provide a mandate for habitat restoration and reintroduction of Pampas deer so that levels of genetic variation can be preserved and historic patterns of abundance can be reconstructed. However, the source of individuals for reintroduction generally should be from populations geographically closest to those now in danger of extinction.

Multiwavelength visible and white light generation by upconversion emission in Ho/Tm/Yb triply doped fluorogermanate glass-ceramic

Energy transfer excited multiwavelength visible upconversion emission and white light generation is described in a single sample of PbGeO(3)-PbF(2)-CdF(2) glass-ceramic triply doped With Ho/Tm/Yb under single infrared laser excitation. Blue (475 nm), green (540 mn), and red (650 nm), upconversion luminescence signals are generated, and the emissions are assigned, respectively, to thulium ((1)G(4)-(3)H(6)), and holmium ((5)S(2);(5)F(4)) -> (5)I(8), (5)F(5) -> (5)I(8)) ions transitions, both excited via successive energy transfers from ytterbium ions. It is experimentally shown that with a proper combination of the rare earth ions contents, white light may be produced, with the simultaneous generation of fluorescence with controllable intensities at the wavelengths of the three primary colours in a single sample and using a single near-infrared excitation source.

Influence of light curing source on microhardness of composite resins of different shades

Introduction: The evolution of light curing units can be noticed by the different systems recently introduced. The technology of LED units promises longer lifetime, without heating and with production of specific light for activation of camphorquinone. However, further studies are still required to check the real curing effectiveness of these units. Purpose: This study evaluated the microhardness of 4 shades (B-0.5, B-1, B-2 and B-3) of composite resin Filtek Z-250 (3M ESPE) after light curing with 4 light sources, being one halogen (Ultralux - Dabi Atlante) and three LED (Ultraled - Dabi Atlante, Ultrablue - DMC and Elipar Freelight - 3M ESPE). Methods: 192 specimens were distributed into 16 groups, and materials were inserted in a single increment in cylindrical templates measuring 4mm x 4mm and light cured as recommended by the manufacturer. Then, they were submitted to microhardness test on the top and bottom aspects of the cylinders. Results: The hardness values achieved were submitted to analysis of variance and to Tukey test at 5% confidence level. It was observed that microhardness of specimens varied according to the shade of the material and light sources employed. The LED appliance emitting greater light intensity provided the highest hardness values with shade B-0.5, allowing the best curing. On the other hand, appliances with low light intensity were the least effective. It was also observed that the bottom of specimens was more sensitive to changes in shade. Conclusion: Light intensity of LED light curing units is fundamental for their good functioning, especially when applied in resins with darker shades.

Nonlinear effects generation in suspended core chalcogenide fibre

In this work we report our achievements in the elaboration and optical characterizations of low-losses suspended core optical fibers elaborated from As2S3 glass. For preforms elaboration, alternatively to other processes like the stack and draw or extrusion, we use a process based on mechanical drilling. The drawing of these drilled performs into fibers allows reaching a suspended core geometry, in which a 2 μm diameter core is linked to the fiber clad region by three supporting struts. The different fibers that have been drawn show losses close to 0.9 dB/m at 1.55 μm. The suspended core waveguide geometry has also an efficient influence on the chromatic dispersion and allows its management. Indeed, the zero dispersion wavelength, which is around 5 μm in the bulk glass, is calculated to be shifted towards around 2μm in our suspended core fibers. In order to qualify their nonlinearity we have pumped them at 1.995 μm with the help of a fibered ns source. We have observed a strong non linear response with evidence of spontaneous Raman scattering and strong spectral broadening. © 2011 SPIE.

Optimal allocation of distributed generators providing reactive power support ancillary service

Problems as voltage increase at the end of a feeder, demand supply unbalance in a fault condition, power quality decline, increase of power losses, and reduction of reliability levels may occur if Distributed Generators (DGs) are not properly allocated. For this reason, researchers have been employed several solution techniques to solve the problem of optimal allocation of DGs. This work is focused on the ancillary service of reactive power support provided by DGs. The main objective is to price this service by determining the costs in which a DG incurs when it loses sales opportunity of active power, i.e, by determining the Loss of Opportunity Costs (LOC). The LOC will be determined for different allocation alternatives of DGs as a result of a multi-objective optimization process, aiming the minimization of losses in the lines of the system and costs of active power generation from DGs, and the maximization of the static voltage stability margin of the system. The effectiveness of the proposed methodology in improving the goals outlined was demonstrated using the IEEE 34 bus distribution test feeder with two DGs cosidered to be allocated. © 2011 IEEE.

Baccharis dracunculifolia, the main source of green propolis, exhibits potent antioxidant activity and prevents oxidative mitochondrial damage

Baccharis dracunculifolia DC (Asteraceae) is the main botanical source used by honeybees to produce Brazilian green propolis whose hepatoprotective properties have been already described. In this work we investigated the protective effects of the glycolic extract of B. dracunculifolia (GEBd) against oxidative stress in isolated rat liver mitochondria (RLM). The GEBd was prepared by fractionated percolation using propylene glycol as solvent. The total phenols and flavonoids, which are substances with recognized antioxidant action, were quantified in GEBd and the phytochemical analysis was carried out by HPLC. GEBd exhibited significant scavenger activity towards DPPH radicals and superoxide anions in a concentration-dependent manner, and also a Fe 2+ chelating activity. GEBd decreased the basal H 2O 2 generation and the Fe 2+- or t-BuOOH-induced ROS production in isolated mitochondria. Lipid oxidation of mitochondrial membranes, protein thiol groups and GSH oxidation were also prevented by GEBd. This shows that B. dracunculifolia exhibit potent antioxidant activity protecting liver mitochondria against oxidative damage and such action probably contribute to the antioxidant and hepatoprotective effects of green propolis. © 2011 Elsevier Ltd.

Mobile application as a tool for urban traffic data collection and generation to advanced traveler information systems using Wi-Fi networks available in urban centers

This paper presents an Advanced Traveler Information System (ATIS) developed on Android platform, which is open source and free. The developed application has as its main objective the free use of a Vehicle-to- Infrastructure (V2I) communication through the wireless network access points available in urban centers. In addition to providing the necessary information for an Intelligent Transportation System (ITS) to a central server, the application also receives the traffic data close to the vehicle. Once obtained this traffic information, the application displays them to the driver in a clear and efficient way, allowing the user to make decisions about his route in real time. The application was tested in a real environment and the results are presented in the article. In conclusion we present the benefits of this application. © 2012 IEEE.

Distributed generators as providers of reactive power support - A market approach

Traditionally, ancillary services are supplied by large conventional generators. However, with the huge penetration of distributed generators (DGs) as a result of the growing interest in satisfying energy requirements, and considering the benefits that they can bring along to the electrical system and to the environment, it appears reasonable to assume that ancillary services could also be provided by DGs in an economical and efficient way. In this paper, a settlement procedure for a reactive power market for DGs in distribution systems is proposed. Attention is directed to wind turbines connected to the network through synchronous generators with permanent magnets and doubly-fed induction generators. The generation uncertainty of this kind of DG is reduced by running a multi-objective optimization algorithm in multiple probabilistic scenarios through the Monte Carlo method and by representing the active power generated by the DGs through Markov models. The objectives to be minimized are the payments of the distribution system operator to the DGs for reactive power, the curtailment of transactions committed in an active power market previously settled, the losses in the lines of the network, and a voltage profile index. The proposed methodology was tested using a modified IEEE 37-bus distribution test system. © 1969-2012 IEEE.

Improving the grid operation and reliability cost of distribution systems with dispersed generation

In this work, a mathematical model to analyze the impact of the installation and operation of dispersed generation units in power distribution systems is proposed. The main focus is to determine the trade-off between the reliability and operational costs of distribution networks when the operation of isolated areas is allowed. In order to increase the system operator revenue, an optimal power flow makes use of the different energy prices offered by the dispersed generation connected to the grid. Simultaneously, the type and location of the protective devices initially installed on the protection system are reconfigured in order to minimize the interruption and expenditure of adjusting the protection system to conditions imposed by the operation of dispersed units. The interruption cost regards the unsupplied energy to customers in secure systems but affected by the normal tripping of protective devices. Therefore, the tripping of fuses, reclosers, and overcurrent relays aims to protect the system against both temporary and permanent fault types. Additionally, in order to reduce the average duration of the system interruption experienced by customers, the isolated operation of dispersed generation is allowed by installing directional overcurrent relays with synchronized reclose capabilities. A 135-bus real distribution system is used in order to show the advantages of using the mathematical model proposed. © 1969-2012 IEEE.

Three-dimensional modeling and highly refined mesh generation of the aorta artery and its tunics

This paper describes strategies and techniques to perform modeling and automatic mesh generation of the aorta artery and its tunics (adventitia, media and intima walls), using open source codes. The models were constructed in the Blender package and Python scripts were used to export the data necessary for the mesh generation in TetGen. The strategies proposed are able to provide meshes of complicated and irregular volumes, with a large number of mesh elements involved (12,000,000 tetrahedrons approximately). These meshes can be used to perform computational simulations by Finite Element Method (FEM). © Published under licence by IOP Publishing Ltd.

Free tools and strategies for the generation of 3D finite element meshes: Modeling of the cardiac structures

The Finite Element Method is a well-known technique, being extensively applied in different areas. Studies using the Finite Element Method (FEM) are targeted to improve cardiac ablation procedures. For such simulations, the finite element meshes should consider the size and histological features of the target structures. However, it is possible to verify that some methods or tools used to generate meshes of human body structures are still limited, due to nondetailed models, nontrivial preprocessing, or mainly limitation in the use condition. In this paper, alternatives are demonstrated to solid modeling and automatic generation of highly refined tetrahedral meshes, with quality compatible with other studies focused on mesh generation. The innovations presented here are strategies to integrate Open Source Software (OSS). The chosen techniques and strategies are presented and discussed, considering cardiac structures as a first application context. © 2013 E. Pavarino et al.

Evaluation of Rice Bran Extract as a Nitrogen Source for Improved Hemicellulosic Ethanol Production from Sugarcane Bagasse by New Xylose-Fermenting Yeast Strains Isolated from Brazilian Forests

Xylose is the main sugar in hemicellulosic hydrolysates and its fermentation into ethanol by microorganisms is influenced by nutritional factors, such as nitrogen source, vitamins and other elements. Rice bran extract (RBE) is an inexpensive nitrogen source primarily consisting of high amount of protein. This study evaluates the potential of RBE as a nitrogen source for the hemicellulosic ethanol production from sugarcane bagasse dilute acid hydrolysate by novel yeast strains Scheffersomyces shehatae (syn. Candida shehatae) CG8-8BY and Spathaspora arborariae UFMG-HM19.1A, isolated from Brazilian forests. Two different media formulations were used for inoculum preparation and production medium, using yeast extract and RBE as nitrogen sources. S. shehatae CG8-8BY showed ethanol production of 17.0 g/l with the ethanol yield (0.33 g/g) and fermentation efficiency (64 %) from medium supplemented with RBE. On the other hand, S. arborariae presented 5.4 g/l of ethanol production with ethanol yield (0.14 g/g) and fermentation efficiency (21 %) in a fermentation medium supplemented with RBE. Appropriate media formulation is an important parameter to increase the productivity of bioconversion process and RBE proved to be an efficient and inexpensive nitrogen source to supplement sugarcane bagasse hemicellulosic hydrolysate for second generation ethanol production. © 2013 Society for Sugar Research & Promotion.

Produção científica docente em tratamento temático da informação no Brasil: uma abordagem métrica como subsídio para a análise do domínio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)