15,086 research outputs found

    Hemispherical power asymmetries in the WMAP 7-year low-resolution temperature and polarization maps

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    We test the hemispherical power asymmetry of the WMAP 7-year low-resolution temperature and polarization maps. We consider two natural estimators for such an asymmetry and exploit our implementation of an optimal angular power spectrum estimator for all the six CMB spectra. By scanning the whole sky through a sample of 24 directions, we search for asymmetries in the power spectra of the two hemispheres, comparing the results with Monte Carlo simulations drawn from the WMAP 7-year best-fit model. Our analysis extends previous results to the polarization sector. The level of asymmetry on the ILC temperature map is found to be compatible with previous results, whereas no significant asymmetry on the polarized spectra is detected. Moreover, we show that our results are only weakly affected by the a posteriori choice of the maximum multipole considered for the analysis. We also forecast the capability to detect dipole modulation by our methodology at Planck sensitivity.Comment: 7 pages, 9 figures. Accepted for publication in MNRA

    Assessing the influence of the carbon oxidation-reduction state on organic pollutant biodegradation in algal-bacterial photobioreactors

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    The influence of the carbon oxidation-reduction state (CORS) of organic pollutants on their biodegradation in enclosed algal-bacterial photobioreactors was evaluated using a consortium of enriched wild-type methanotrophic bacteria and microalgae. Methane, methanol and glucose (with CORS -4, -2 and 0, respectively) were chosen as model organic pollutants. In the absence of external oxygen supply, microalgal photosynthesis was not capable of supporting a significant methane and methanol biodegradation due to their high oxygen demands per carbon unit, while glucose was fully oxidized by photosynthetic oxygenation. When bicarbonate was added, removal efficiencies of 37¿±¿4% (20 days), 65¿±¿4% (11 days) and 100% (2 days) were recorded for CH(4,) CH(3)OH and C(6)H(12)O(6), respectively due to the additional oxygen generated from photosynthetic bicarbonate assimilation. The use of NO(3)(-) instead of NH(4)(+) as nitrogen source (N oxidation-reduction state of +5 vs. -3) resulted in an increase in CH(4) degradation from 0 to 33¿±¿3% in the absence of bicarbonate and from 37¿±¿4% to 100% in the presence of bicarbonate, likely due to a decrease in the stoichiometric oxygen requirements and the higher photosynthetic oxygen production. Hypothetically, the CORS of the substrates might affect the CORS of the microalgal biomass composition (higher lipid content). However, the total lipid content of the algal-bacterial biomass was 19¿±¿7% in the absence and 16¿±¿2% in the presence of bicarbonat

    The effect of the environment on the Faber Jackson relation

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    We investigate the effect of the environment on the Faber Jackson (FJ) relation, using a sample of 384 nearby elliptical galaxies and estimating objectively their environment on the typical scale of galaxy clusters. We show that the intrinsic scatter of the FJ is significantly reduced when ellipticals in high density environments are compared to ellipticals in low density ones. This result, which holds on a limited range of overdensities, is likely to provide an important observational link between scaling relations and formation mechanisms in galaxies.Comment: accepted by Ap

    Hadronic decays of the tau lepton into K K pion modes within Resonance Chiral Theory

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    Tau decays into hadrons have a twofold interest: On the one hand, they are a clean environment for studying the hadronization of the left-handed current of QCD, while, on the other side, provide relevant dynamical information of the resonances that mediate these processes. Within an effective field theory-like framework, namely Resonance Chiral Theory, we analyse the decays ot the tau into K K pion modes and compare the results with CLEO and BaBar data. In this way, we provide bounds on the couplings entering our Lagrangian and predict the corresponding spectral functions. As a main result -and contrary to the bulk of theoretical studies and experimental analyses- we find vector current dominance on these decays.Comment: 7 pages, 1 figure, Prepared for the conference QCD@Work07 in Martina Franca, Bari, Italy. To appear in the Proceeding

    Água-de-coco: métodos de conservação.

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    Atualmente, a cocoicultura e considerada a segunda cultura frutifera de importancia economica na regiao Nordeste brasileira, tendo os Tabuleiros Costeiros como maiores produtores. Em meados de 1990, ocorreu uma busca acirrada por produtos de coco oriundos ded paises africanos e asiaticos que trabalham com culturas subsidiadas (Sri Lanka, Costa do Marfin, Indonesia e Felipinas). O preco atrativo nao permitia a concorrencia com os produtos de origem nacional, levando os produtos de coco da regiao a situacoes de inviabilizacao de suas culturas. (...) Atualmente, a agua de coco verde consiste em um grande ramo de comercializacao de cocos da variedade anã verde, com acessos notadamente a mercados distantes dos produtores.bitstream/CNPAT-2010/4873/1/Dc-037.pd

    Variáveis relacionadas ao rendimento da incubação de ovos em matrizes de frangos de corte.

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    bitstream/item/58383/1/CUsersPiazzonDocuments246.pdfAcesso em: 13 jun. 2007
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