Modélisation de l’atténuation au sol de la concentration des émissions d’une centrale thermique diesel

A ground level diesel power plant pollutants mitigation modelA three steps environmental mitigation model is investigated as a way of controlling the emission rates of a 44 MW diesel electric power plant located in downtown Ouagadougou. First of all, an environmental audit finds it necessary to rehabilitate the plant in order to improve its performances. To be effective however, the upper limit of the plant fuel consumption should not exceed 229 g/kWh. Finally, dispersion diagrams are obtained from a simplified dispersion-advection submodel, capable of predicting the plant stack high for which, the ground level pollutant concentrations must compley with the ambient air quality standards. Thus, the results of this model may be utilized to control and regulate air pollution

Informational spillovers in the pre-1914 London Sovereign Debt Market

We document a novel type of international financial contagion whose driving force is shared financial intermediation. In the London peripheral sovereign debt market during pre-1914 period financial intermediation played a major informational role to investors, most likely because of the absence of international monitoring agencies and the substantial agency costs. Using two events of financial distress – the Brazilian Funding Loan of 1898 and the Greek Funding Loan of 1893 – as quasi-natural experiments, we document that, following the crises, the bond prices of countries with no meaningful economic links to the distressed countries, but shared the same financial intermediary, suffered a reduction relative to the rest of the market. This result is true for the mean, median and the whole distribution of bond prices, and robust to an extensive sensitivity analysis. We interpret this as evidence that the identity of the financial intermediary was informative, i.e, investors extracted information about the soundness of a debtor based on the performance of her financial intermediary. This spillover, informational in essence, arises as the flip-side of the relational lending coin: contagion arises for the same reason why relational finance (in this case, underwriting) helps alleviate informational and incentive problems,

Enlightening the structure and dynamics of Abell 1942

We present a dynamical analysis of the galaxy cluster Abell 1942 based on a set of 128 velocities obtained at the European Southern Observatory. Data on individual galaxies are presented and the accuracy of the determined velocities is discussed as well as some properties of the cluster. We have also made use of publicly available Chandra X-ray data. We obtained an improved mean redshift value z = 0.22513 \pm 0.0008 and velocity dispersion sigma = 908^{+147}_{-139} km/s. Our analysis indicates that inside a radius of ~1.5 h_{70}^{-1} Mpc (~7 arcmin) the cluster is well relaxed, without any remarkable feature and the X-ray emission traces fairly well the galaxy distribution. Two possible optical substructures are seen at ~5 arcmin from the centre towards the Northwest and the Southwest direction, but are not confirmed by the velocity field. These clumps are however, kinematically bound to the main structure of Abell 1942. X-ray spectroscopic analysis of Chandra data resulted in a temperature kT = 5.5 \pm 0.5 keV and metal abundance Z = 0.33 \pm 0.15 Z_odot. The velocity dispersion corresponding to this temperature using the T_X-sigma scaling relation is in good agreement with the measured galaxies velocities. Our photometric redshift analysis suggests that the weak lensing signal observed at the south of the cluster and previously attributed to a "dark clump", is produced by background sources, possibly distributed as a filamentary structure.Comment: Accepted for publication in Astronomy & Astrophysics, 15 pages, 15 figures, table w/ positions, photometric data and redshift

Discrepâncias entre resultados de reações de Guerreiro-Machado executadas em diferentes laboratórios

Reações de fixação de complemento feitas em três laboratórios, usando basicamente a mesma técnica, apresentaram resultados discrepantes com soros chagásicos. Somente 16 soros de um lote de 26 pacientes em fase aguda de infecção tiveram resultados positivos nos três laboratórios, embora nenhum deles fosse unanimente negativo. Quando 224 soros de casos parasitologicamente comprovados de doença de Chagas foram examinados, resultados positivos foram obtidos em 95% deles em um laboratório, 89% em outro e apenas 64% no terceiro. Os resultados mostraram que as discrepãncias observadas dependiam da qualidade dos antígenos usados, dando ênfase à necessidade não só da padronização dos preparados antigênicos, como também da metodologia do teste, a fim de se poder ter resultados comparáveis quanto à sensibilidade e especificidade da reação de Guerreiro-Machado.Complement-fixation tests performed in three laborarories, using basically the same tecnique, presented discrepant results with Chagasic sera. Only 16 sera from a lot of 26 in the acute phase of the infection had positive tests in the three laboratories, although none of them presented a consensus of negative tests. When 224 sera from parasitologically proven cases of Chagas disease were tested, positive results were obtained in 95% of them in one laboratory, 89% in the second one and only 64% in the other. The results showed that the discrepancies observeddependedof the quality of the antigens used, stressing the necessity of the standardization not only of the antigen preparations but also of the methodology of the tests, in order to have comparable results in the Guerreiro-Machado tests, in sensitivity and specificity

Shrinking of Cluster Ellipticals: a Tidal Stripping explanation and Implications for the Intra-Cluster Light

We look for evidence of tidal stripping in elliptical galaxies through the analysis of homogeneous CCD data corresponding to a sample of 228 elliptical galaxies belonging to 24 clusters of galaxies at $0.015<z<0.080$. We investigate departures from the standard magnitude-isophotal size relation, as a function of environmental (cluster-centric distance, local galaxy density) and structural (cluster velocity dispersion, Bautz-Morgan type) properties. We find that, for any particular galaxy luminosity, the ellipticals in the inner and denser regions of the clusters are about 5% smaller than those in the outer regions, which is in good agreement with the finding of Strom & Strom (1978) based on photographic photometry. The null hypothesis (ie., galaxy sizes are independent of the cluster-centric distance or density) is rejected at a significance level of better than 99.7%. Numericals models of Aguilar & White (1986) predict that tidal stripping can lead to changes in the whole structure of ellipticals producing shrinkage and brightening of the galaxy, qualitatively consistent with our measurements and also with the findings of Trujillo et al. (2002), that more centrally concentrated ellipticals populate denser regions. Our observational results can be interpreted as evidence for stripping of stars from ellipticals in the central/denser regions of clusters, contributing to the intra-cluster light observed in these structures.Comment: AJ Accepted, 15 pages, 9 figure

Projecto para a creação de universidades no Brazil

Acima do título: Publicações do "Brazil-medico"

Structure and dynamics of the Shapley Supercluster

We present results of our wide-field redshift survey of galaxies in a 285 square degree region of the Shapley Supercluster (SSC), based on a set of 10529 velocity measurements (including 1201 new ones) on 8632 galaxies obtained from various telescopes and from the literature. Our data reveal that the main plane of the SSC (v~ 14500 km/s) extends further than previous estimates, filling the whole extent of our survey region of 12~degrees by 30~degrees on the sky (30 x 75~h-1 Mpc). There is also a connecting structure associated with the slightly nearer Abell~3571 cluster complex (v~ 12000km/s. These galaxies seem to link two previously identified sheets of galaxies and establish a connection with a third one at V= 15000 km/s near R.A.= 13h. They also tend to fill the gap of galaxies between the foreground Hydra-Centaurus region and the more distant SSC. In the velocity range of the Shapley Supercluster (9000 km/s < cz < 18000 km/s), we found redshift-space overdensities with b\_j < 17.5 of ~5.4 over the 225 square degree central region and ~3.8 in a 192 square degree region excluding rich clusters. Over the large region of our survey, we find that the intercluster galaxies make up 48 per cent of the observed galaxies in the SSC region and, accounting for the different completeness, may contribute nearly twice as much mass as the cluster galaxies. In this paper, we discuss the completeness of the velocity catalogue, the morphology of the supercluster, the global overdensity, and some properties of the individual galaxy clusters in the Supercluster.Comment: Accepted for publication in Astronomy and Astrophysic

Luís Saia e a formação de uma geração

By analysing Luis Saia’s trajectory in addition to his work in the preservation and restoration of historical heritage in São Paulo, this paper attempted to place it within the broader framework of his generation. From this understanding, it was possible to discuss his contribution to the formative years of architecture students from the 50s, with the creation of the School of Architecture and Planning in the University of São Paulo (FAU-USP), recognizing the device of the journey as an formative experience, for both generations.Mediante el análisis de la trayectoria de Luís Saia, además de su trabajo en la preservación y restauración del patrimonio histórico en São Paulo, el presente trabajo intenta colocarlo en el marco más amplio de su generación. A partir de este entendimiento, fue posible para hablar de su contribución a los años de formación de estudiantes de arquitectura de los años 50, con la creación de la Escuela de Arquitectura y Urbanismo de la Universidad de São Paulo (FAU-USP), reconociendo el dispositivo de la viaje como una experiencia formativa, para las dos generaciones.Ao mapear o campo de atuação de Luís Saia para além de seus trabalhos junto de preservação e restauração do patrimônio histórico em São Paulo, o artigo procurou situá-lo dentro do quadro mais amplo de sua geração. A partir deste entendimento, foi possível discorrer sobre sua contribuição na formação do novos arquitetos a partir dos anos 50, com a criação da Faculdade de Arquitetura e Urbanismo da Universidade de São Paulo (FAU- USP), reconhecendo o dispositivo da viagem como uma experiência formativa fundamental, tanto para a nova quanto para sua geração