178 research outputs found

    Interpolation of bilinear operators and compactness

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    The behavior of bilinear operators acting on interpolation of Banach spaces for the ρ\rho method in relation to the compactness is analyzed. Similar results of Lions-Peetre, Hayakawa and Person's compactness theorems are obtained for the bilinear case and the ρ\rho method.Comment: This work was published at "Nonlinear Analysis: Theory, Methods and Applications, Volume 73, Issue 2, 2010, Pages 526-537". Since there are some gaps in the original proof of Theorem 4.3, Here we give a new proof. For this, we change the Lemma 4.

    Finite-size scaling in unbiased translocation dynamics

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    Finite-size scaling arguments naturally lead us to introduce a coordinate-dependent diffusion coefficient in a Fokker-Planck description of the late stage dynamics of unbiased polymer translocation through a membrane pore. The solution for the probability density function of the chemical coordinate matches the initial-stage subdiffusive regime and takes into account the equilibrium entropic drive. Precise scaling relations connect the subdiffusion exponent to the divergence with the polymer length of the translocation time, and also to the singularity of the probability density function at the absorbing boundaries. Quantitative comparisons with numerical simulation data in d=2d=2 strongly support the validity of the model and of the predicted scalings.Comment: Text revision. Supplemental Material adde

    Hausdorff Measures of Noncompactness and Interpolation Spaces

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    2000 Mathematics Subject Classification: 46B50, 46B70, 46G12.A new measure of noncompactness on Banach spaces is defined from the Hausdorff measure of noncompactness, giving a quantitative version of a classical result by R. S. Phillips. From the main result, classical results are obtained now as corollaries and we have an application to interpolation theory of Banach spaces

    UTCI field measurements in an urban park in Florence (Italy)

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    The aim of this study is to evaluate human thermal comfort in different green area settings in the city of Florence by using the Universal Thermal Climate Index (UTCI). Field measurements of air temperature, solar radiation, relative humidity, wind speed and black globe thermometer were collected during hot summer days in various parts of Cascine Park, the biggest urban park in Florence (Italy). UTCI was evaluated over different surfaces (asphalt, gravel and grass) completely exposed to the sun or shaded by a large lime tree (Tilia × europaea). The results showed strong differences in UTCI values depending on the exposure to tree shade, while no significant difference was found among ground-cover materials when all surfaces were equally exposed to solar radiation. Future studies are needed to investigate the microclimatic effects of different tree species on UTCI

    CO2 adsorption on different organo-­‐modified SBA-­‐15 silicas: a multidisciplinary study on the effects of basic surface groups

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    Hybrid organic–inorganic SBA-15 silicas functionalized with increasing amounts of amino groups were studied in this work aiming to evaluate the effects of their physico-chemical properties on CO2 capture ability. Three different amino-silane species were used: 3-aminopropyltriethoxysilane (APTS), 3-(2-aminoethyl)- aminopropyltrimethoxysilane (EAPTS) and 3-[2-(2-aminoethyl)aminoethyl] aminopropyltrimethoxysilane (PAPTS). More specifically, samples were prepared by using two methods, following a post-synthesis grafting procedure and a one-pot preparation method. Experimental and computational techniques were used to study the structural and textural properties of the obtained samples and their surface species in relation to the adopted preparation method. For the most reactive samples, additional hints on the interactions of organosilane species with the silica surface were obtained by a combination of IR and SS-NMR spectroscopy, with particular emphasis on the effects of the silane chain length on the mobility of the organic species. Advanced complementary solid-state NMR techniques provided deeper information on the interactions of organosilane species with the silica surface. Finally, the amount of CO2 adsorbed was estimated by comparing the classical microcalorimetric analysis method with a new type of screening test, the Zero Length Column analysis, which is able to evaluate small amounts of samples in a very short time and the adsorption properties of the adsorbents. The reactivity of the amino-modified silica samples is deeply influenced by both the preparation route and by the type of organosilane used for the functionalization of the materials. In particular, samples prepared by the post-synthesis grafting procedure and containing higher amount of amino groups in the chain are more reactive, following the order PAPTS 4 EAPTS 4 APTS
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