4,512 research outputs found

    Support for the value 5/2 for the spin glass lower critical dimension at zero magnetic field

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    We study numerically various properties of the free energy barriers in the Edwards-Anderson model of spin glasses in the low-temperature region both in three and four spatial dimensions. In particular, we investigated the dependence of height of free energy barriers on system size and on the distance between the initial and final states (i.e. the overlap distance). A related quantity is the distribution of large local fluctuations of the overlap in large three-dimensional samples at equilibrium. Our results for both quantities (barriers and large deviations) are in agreement with the prediction obtained in the framework of mean field theory. In addition, our result supports Dlc=2.5D_{lc}=2.5 as the lower critical dimension for the model.Comment: 11 pages, 4 figures. To appear in PNA

    Public libraries in the social accountability of local administrations

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    This work represents a first reflection with respect to certain issues such as: - the importance of social reporting, and in particular the use of the social accountability for public libraries Italian in order to communicate more effectively on the outside their values; being generally recognized the effectiveness of the balance for the purposes of reporting, there does not seem to be any reasons why libraries should not take advantage of such an instrument; - a higher visibility of public libraries, perceived not only by the professionals in the industry, but also by the public administrations, in order to make more significant component the local librarian within the administrations of reference, as agency for change in the community and therefore of necessary service; - analysis of best practices to recognized today, in order to highlight the methodologies and the main features of some excellent Italian examples; - Proposal for a methodology of investigation, through which retrieve the information necessary for the preparation of a social accountability, based on standard can also be used in scope librarian, as ISO 2789, 11620, 16489

    MIOCENE QUANTITATIVE CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY FROM SOUTHERN APENNINES FOREDEEP DEPOSITS AND MEDITERRANEAN DSDP SITE 372

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    A quantitative biostratigraphic study based on calcareous nannofossil assemblages was carried out in nine Miocene calcareous and siliciclastic foredeep sections, cropping out in the outer part of the Southern Apennines and generally ascribed to the external Irpinian units. Several biozonal events were recognised by means of quantitative analyses, according to the biostratigraphic schemes of Fornaciari & Rio (1996) and Fornaciari et al. (1996) for the lower and middle Miocene and of Theodoridis (1984) for the upper Miocene. In the lower and middle Miocene interval some biohorizons such as the first common occurrence of Helicosphaera walbersdorfensis and last common occurrence of Calcidiscus premacintyrei are not always detectable in the studied sections and the first common occurrence of Calcidiscus macintyrei appears to be a better biohorizon in the MNN6b/7 than the last common occurrence of C. premacintyrei. New data on abundance patterns of selected calcareous nannofossils have been collected, thus improving the biostratigraphic resolution of the zonal schemes: a paracme interval of small Reticulofenestra pseudoumbilicus was noted within Zone MNN4b and MNN5a; the beginning and the end of the paracme are useful events in the studied sections for stratigraphic correlations. Moreover the occurrence of R. pseudoumbilicus has been recorded from Zone MNN2b on upwards, fairly below the FCO of the species that defines the base of Zone MNN6b. The distributions observed in the on-land sections are consistent with those recognised in DSDP Site 372 located in the western Mediterranean Sea, confirming their potential biostratigraphic utility within the Mediterranean region.&nbsp
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