983 resultados para Acanthoica quattrospina flux


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L’attrait des compagnies pharmaceutiques pour des structures cycliques possédant des propriétés biologiques intéressantes par les compagnies pharmaceutiques a orienté les projets décrits dans ce mémoire. La synthèse rapide, efficace, verte et économique de ces structures suscite de plus en plus d’attention dans la littérature en raison des cibles biologiques visées qui deviennent de plus en plus complexes. Ce mémoire se divise en deux projets ciblant la synthèse de deux structures aromatiques importantes dans le monde de la chimie médicinale. Dans un premier temps, l’amélioration de la synthèse de dérivés phénoliques a été réalisée. L’apport de la chimie en flux continu dans le développement de voies synthétiques plus vertes et efficaces sera tout d’abord discuté. Ensuite, une revue des antécédents concernant l’hydroxylation d’halogénure d’aryle sera effectuée. Finalement, le développement d’une nouvelle approche rapide de synthèse des phénols utilisant la chimie en flux continu sera présenté, suivi d’un survol de ses avantages et ses limitations. Dans un deuxième temps, le développement d’une nouvelle méthodologie pour la formation de 3-aminoindazoles a été réalisé. Tout d’abord, un résumé de la littérature sur la synthèse de différents indazoles sera présenté. Ensuite, une présentation de deux méthodes efficaces d’activation de liens sera effectuée, soit l’activation d’amides par l’anhydride triflique et l’activation de liens C–H catalysée par des métaux de transition. Finalement, le développement d’une nouvelle méthodologie pour la synthèse de 3-aminoindazole utilisant ces deux approches sera discuté.

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The need for reliable predictions of the solar activity cycle motivates the development of dynamo models incorporating a representation of surface processes sufficiently detailed to allow assimilation of magnetographic data. In this series of papers we present one such dynamo model, and document its behavior and properties. This first paper focuses on one of the model's key components, namely surface magnetic flux evolution. Using a genetic algorithm, we obtain best-fit parameters of the transport model by least-squares minimization of the differences between the associated synthetic synoptic magnetogram and real magnetographic data for activity cycle 21. Our fitting procedure also returns Monte Carlo-like error estimates. We show that the range of acceptable surface meridional flow profiles is in good agreement with Doppler measurements, even though the latter are not used in the fitting process. Using a synthetic database of bipolar magnetic region (BMR) emergences reproducing the statistical properties of observed emergences, we also ascertain the sensitivity of global cycle properties, such as the strength of the dipole moment and timing of polarity reversal, to distinct realizations of BMR emergence, and on this basis argue that this stochasticity represents a primary source of uncertainty for predicting solar cycle characteristics.

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Two-sided flux decoration experiments indicate that threading dislocation lines (TDLs), which cross the entire film, are sometimes trapped in metastable states. We calculate the elastic energy associated with the meanderings of a TDL. The TDL behaves as an anisotropic and dispersive string with thermal fluctuations largely along its Burgers vector. These fluctuations also modify the structure factor of the vortex solid. Both effects can, in principle, be used to estimate the elastic moduli of the material.

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Anàlisi del flux de manterials que travessen el sector de la fusta a Catalunya durant l’any 2005 calculant els balanços de matèria i els indicadors derivats, de cara a avaluar la gestió dels boscos a Catalunya

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Les consultes d’infermeria contribueixen com una porta d’entrada normalitzada en el sistema d’Atenció Primària, oferint resposta a la demanda habitual d’un número important de ciutadans. Una expectativa és reduir els cost i el volum de treball dels metges, sempre que es mantingui la qualitat de l’atenció al ciutadà. La millora organitzativa vers l’accessibilitat al Centre de Salut millora la satisfacció de ciutadans i professionals.

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Most parameterizations for precipitating convection in use today are bulk schemes, in which an ensemble of cumulus elements with different properties is modelled as a single, representative entraining-detraining plume. We review the underpinning mathematical model for such parameterizations, in particular by comparing it with spectral models in which elements are not combined into the representative plume. The chief merit of a bulk model is that the representative plume can be described by an equation set with the same structure as that which describes each element in a spectral model. The equivalence relies on an ansatz for detrained condensate introduced by Yanai et al. (1973) and on a simplified microphysics. There are also conceptual differences in the closure of bulk and spectral parameterizations. In particular, we show that the convective quasi-equilibrium closure of Arakawa and Schubert (1974) for spectral parameterizations cannot be carried over to a bulk parameterization in a straightforward way. Quasi-equilibrium of the cloud work function assumes a timescale separation between a slow forcing process and a rapid convective response. But, for the natural bulk analogue to the cloud-work function (the dilute CAPE), the relevant forcing is characterised by a different timescale, and so its quasi-equilibrium entails a different physical constraint. Closures of bulk parameterization that use the non-entraining parcel value of CAPE do not suffer from this timescale issue. However, the Yanai et al. (1973) ansatz must be invoked as a necessary ingredient of those closures.

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In this paper we pledge that physically based equations should be combined with remote sensing techniques to enable a more theoretically rigorous estimation of area-average soil heat flux, G. A standard physical equation (i.e. the analytical or exact method) for the estimation of G, in combination with a simple, but theoretically derived, equation for soil thermal inertia (F), provides the basis for a more transparent and readily interpretable method for the estimation of G; without the requirement for in situ instrumentation. Moreover, such an approach ensures a more universally applicable method than those derived from purely empirical studies (employing vegetation indices and albedo, for example). Hence, a new equation for the estimation of Gamma(for homogeneous soils) is discussed in this paper which only requires knowledge of soil type, which is readily obtainable from extant soil databases and surveys, in combination with a coarse estimate of moisture status. This approach can be used to obtain area-averaged estimates of Gamma(and thus G, as explained in paper II) which is important for large-scale energy balance studies that employ aircraft or satellite data. Furthermore, this method also relaxes the instrumental demand for studies at the plot and field scale (no requirement for in situ soil temperature sensors, soil heat flux plates and/or thermal conductivity sensors). In addition, this equation can be incorporated in soil-vegetation-atmosphere-transfer models that use the force restore method to update surface temperatures (such as the well-known ISBA model), to replace the thermal inertia coefficient.

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For vegetated surfaces, calculation of soil heat flux, G, with the Exact or Analytical method requires a harmonic analysis of below-canopy soil surface temperature, to obtain the shape of the diurnal course of G. When determining G with remote sensing methods, only composite (vegetation plus soil) radiometric brightness temperature is available. This paper presents a simple equation that relates the sum of the harmonic terms derived for the composite radiometric surface temperature to that of belowcanopy soil surface temperature. The thermal inertia, Gamma(,) for which a simple equation has been presented in a companion paper, paper I, is used to set the magnitude of G. To assess the success of the method proposed in this paper for the estimation of the diurnal shape of G, a comparison was made between 'remote' and in situ calculated values from described field sites. This indicated that the proposed method was suitable for the estimation of the shape of G for a variety of vegetation types and densities. The approach outlined in paper I, to obtain Gamma, was then combined with the estimated harmonic terms to predict estimates of G, which were compared to values predicted by empirical remote methods found in the literature. This indicated that the method proposed in the combination of papers I and II gave reliable estimates of G, which, in comparison to the other methods, resulted in more realistic predictions for vegetated surfaces. This set of equations can also be used for bare and sparsely vegetated soils, making it a universally applicable method. (C) 2007 Elsevier B.V. All rights reserved.