241 research outputs found

    Avaliação e qualificação das patologias das alvenarias de vedação nas edificações

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    Orientador : Mauro Lacerda Santos FilhoDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Construção Civil. Defesa: Curitiba, 20/04/2010Inclui bibliografiaÁrea de concentração : Ambiente construídoResumo: Este trabalho propõe um modelo de avaliação qualitativa das condições patológicas dos elementos de vedações verticais, executadas em blocos cerâmicos nas edificações, através de parâmetros de desempenho. O objetivo é desenvolver e propor uma ferramenta de auxílio na tomada de decisões entre as várias opções de patologias existentes, para escolher os métodos de reparo disponíveis. O estudo inicia-se com a revisão bibliográfica dos materiais cerâmicos empregados nas alvenarias de vedação e as principais manifestações patológicas e suas origens nas alvenarias de vedação e as profissionais qualificados. Sua eficiência é comprovada através da aplicação em estudos de casos, onde é avaliado o desempenho de vários painéis de vedação. Para patologias e severidades semelhantes as avaliações e procedimentos de intervenção tendem a serem próximas.Abstract: This work proposes a model for the evaluation of pathological conditions of the qualitative elements of vertical wall of ceramic bricks in the buildings through performance parameters. The goal is to provide a tool to aid in decision-making among the various options available. The study begins with a literature review of the ceramic materials employed in the masonry wall and the main pathological manifestations and their origins on the walls and the consequences that these entail. Here it is proposed the method of qualitative assessment of pathologies. The basis of assessment is through visual procedure done by qualified professionals. Their efficiency can be established by applying case studies, which assesses the performance of various panels of walls. For pathologies and severity similar assessments and intervention procedures tend to be close

    Formation of new crystal faces on TiO2 particles by treatment with aqueous HF solution or hot sulfuric acid

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    We have demonstrated that new crystal faces are generated on anatase and rutile TiO2 particles by means of chemical etching in aqueous hydrofluoric acid or hot sulfuric acid. In the treatment with aqueous hydrofluoric acid, the {112} face of anatase particles and the {021} face of rutile particles are newly formed. When treated with hot sulfuric acid, anatase particles exposed the {122} face and rutile particles exposed the {001}, {010}, {021} and {121} faces. In both cases, anatase particles are etched at a higher rate than rutile particles. The etched particles are expected to show photocatalytic properties unique to the crystal faces. For example, the {112} face of anatase particles is demonstrated to be active in the oxidation of Pb2+ ions

    Dusty ERO Search behind Two Massive Clusters

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    We performed deep K'-band imaging observations of 2 massive clusters, MS 0451.6-0305 at z = 0.55 and MS 0440.5+0204 at z = 0.19, for searching counterparts of the faint sub-mm sources behind these clusters, which would provide one of the deepest extremely red object(ERO) samples. Comparing our near-infrared images with optical images taken by the Hubble Space Telescope and by the Subaru Telescope, we identified 13 EROs in these fields. The sky distributions of EROs are consistent with the previous results, that there is a sign of strong clustering among detected EROs. Also, the surface density with corrected lensing amplification factors in both clusters are in good agreement with that derived from previous surveys. We found 7 EROs and 3 additional very red objects in a small area (\sim 0.6 arcmin^2) of the MS 0451.6-0305 field around an extended SCUBA source. Many of their optical and near-infrared colors are consistent with dusty star-forming galaxies at high redshifts(z \sim 1.0-4.0), and they may be constituting a cluster of dusty starburst galaxies and/or lensed star-forming galaxies at high redshift. Their red J-K' colors and faint optical magnitudes suggest they are relatively old massive stellar systems with ages(>300 Mega years) suffering from dust obscuration. We also found a surface-density enhancement of EROs around the SCUBA source in the MS 0440.5+0204 field.Comment: 19 pages, 11 figures, Latex(using pasj00.cls). To be published in PASJ vol 55, No. 4(Aug 2003

    High-Resolution Near-Infrared Imaging of the Powerful Radio Galaxy 3C 324 at z = 1.21 with the Subaru Telescope

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    We have obtained high-resolution K'-band images of the powerful z=1.206 radio galaxy 3C 324 with the Subaru telescope under seeing conditions of 0.3--0.4 arcsec. We clearly resolved the galaxy and directly compared it to the optical images obtained with the Hubble Space Telescope. The host galaxy of 3C 324 is revealed to be a moderately luminous elliptical galaxy with a smooth light profile. The effective radius of the galaxy, as determined by profile fitting, is 1.3+-0.1 arcsec (1.2 kpc), which is significantly smaller than the value of 2.2 arcsec, published in Best et al. (1998, MNRAS, 292, 758). The peak of the K'-band light coincides with the position of the radio core, which implies that the powerful AGN lies at the nucleus of the host galaxy. The peak also coincides with the gap in the optical knotty structures which may be a dust lane hiding the UV-optical emission of the AGN from our line of sight; it is very likely that we are seeing the obscuring structure almost edge-on. We clearly detected the `aligned component' in the K'-band image by subtracting a model elliptical galaxy from the observed image. The red R_F702W-K color of the outer region of the galaxy avoiding the aligned component indicates that the near infrared light of the host galaxy is dominated by an old stellar population.Comment: 21 pages (10 figures), accepted for publication in PAS
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