6,131 research outputs found

    Coarse graining scale and effectiveness of hydrodynamic modeling

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    Some basic questions about the hydrodynamical approach to relativistic heavy ion collisions are discussed aiming to clarify how far we can go with such an approach to extract useful information on the properties and dynamics of the QCD matter created. We emphasize the importance of the coarse-graining scale required for the hydrodynamic modeling which determines the space-time resolution and the associated limitations of collective flow observables. We show that certain kinds of observables can indicate the degree of inhomogeneity of the initial condition under less stringent condition than the local thermal equilibrium subjected to the coarse-graining scale compatible to the scenario.Comment: 12 pages, 4 figures, Quark Matter 201

    Effect of lipids on biomass development in anaerobic fixed-bed reactors treating a synthetic dairy waste

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    The aim of this work was to follow the evolution in quantity and quality of the biomass developed during the operation of two anaerobic fixed bed reactors treating a synthetic dairy waste with different lipid contents. The feasibility of a special reactor design that allowed the biomass withdrawal with minimum operation disturbances was tested. The HRT was maintained at 1.5 days and the influent concentration was gradually increased from 3 to 12 g COD/l. Initially, one reactor was loaded with skim milk and the other one with whole milk, with equal organic loading rates (OLR). The effect of lipids was evaluated in terms of reactor performance, total, adhered and entrapped biomass and evolution of biomass quality determined in batch assays by: (i) measuring of potential specific methanogenic activity against direct (acetate, H2/CO2) and indirect (propionate and butyrate) substrates; (ii) measuring of the resistance of acetoclastic bacteria to the presence of sodium oleate. The lipids reduced the adhered fraction of biomass. The methanogenic activity against butyrate was enhanced in the presence of lipids, but no significant effect was detected on the other measured activities. The biomass taken from the reactor fed with lipids was more susceptible to the presence of sodium oleate, but, over the operation period, this susceptibility was reduced

    A note on the large-angle anisotropies in the WMAP cut-sky maps

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    Recent analyses of the WMAP data seem to indicate the possible presence of large-angle anisotropy in the Universe. If confirmed, these can have important consequences for our understanding of the Universe. A number of attempts have recently been made to establish the reality and nature of such anisotropies in the CMB data. Among these is a directional indicator recently proposed by the authors. A distinctive feature of this indicator is that it can be used to generate a sky map of the large-scale anisotropies of the CMB maps. Applying this indicator to full-sky temperature maps we found a statistically significant preferred direction. The full-sky maps used in these analyses are known to have residual foreground contamination as well as complicated noise properties. Thus, here we performed the same analysis for a map where regions with high foreground contamination were removed. We find that the main feature of the full-sky analysis, namely the presence of a significant axis of asymmetry, is robust with respect to this masking procedure. Other subtler anomalies of the full-sky are on the other hand no longer present.Comment: 10 pages, 3 figeres. We performed a similar analysis of arXiv:astro-ph/0511666 by considering the LILC map with a Kp2 sky cut, and find that the presence of a significant axis of asymmetry is robust with respect to this masking procedur

    Determinants of risk reporting by portuguese and spanish non-finance companies

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    Purpose – The paper seeks to assess the risk reporting practices across two European Latin countries (Portugal and Spain). Moreover, drawn on elements of agency, legitimacy, resources-based perspectives, and institutional theory this study also intends to assess if the influence of corporate governance mechanisms on risk reporting is mediated by strategic/institutional legitimacy interests. Design/methodology/approach – From a sample of 60 non-finance Portuguese and Spanish companies with securities traded on the Euronext Lisbon stock exchange market and on the Madrid stock exchange market, respectively, at December, 2011, the Corporate Governance reports and the “risk/risk management” sections of the Management reports included on consolidated annual reports for 2011 were manually content analyzed, according to prior literature. Further, multiple linear regressions were used to assess the potential relationships between corporate governance mechanisms and risk reporting. Findings – Results indicate that visible companies, operating in a country with a weaker legal environment, and during periods of financial distress disclose more discretionary RRD, basically to contextualize their negative outcomes. Some corporate governance mechanisms were crucial to improve risk information. Originality – The paper goes beyond prior literature work and assesses if the theoretical framework grounded on agency, legitimacy, resources-based perspective, and institutional theory is suitable in explaining RRD in an under-researched setting (European Latin countries, such as Portugal and Spain with low agency costs and different corporate governance models). Moreover, the analysis embraces a wider and homogeneous range of internal and external corporate governance mechanisms and uses a period in which both countries were severely affected by a sovereign debt crisis with negative impacts on company’s liquidity and financial risks. A research setting like this has not been studied hitherto.info:eu-repo/semantics/acceptedVersio
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