Indagini archeometriche su alcuni pesi da telaio dalla 'Cisalpina' protostorica

This paper presents the preliminary results of an archaeometric analysis on 13 loom-weights from some protohistoric and pre-roman settlements of southern Veneto. The artefacts are dated to Final Bronze age and 1st Iron age (Mariconda di Melara, Frattesina, Villamarzana - Rovigo), 6th cent. b.C. (Oppeano - Verona) and 3rd-2nd cent. b.C. (Adria - Rovigo). The oldest artefacts from the Polesine area present an annular shape with sub-rounded or sub-quadrangular sections while those from Adria are bun shaped with a narrower inner hole. As regards the sample from Oppeano, it presents an end-pyramid shape with a small circular hole in the upper side. The minero-petrographic analysis by optical microscopy (OM) and X-ray powder diffraction (XRPD) has been addressed to the compositional characterization of these materials to better understand their technological and functional parameters, as well as to identify possible provenance markers useful to constrain local productions. The study has shown how these loom-weights are produced using mainly local raw materials helpful to create a reference group. The research has put the bases for the setting up of a minero-petrographic database on these type of ceramic class. The analysis could be also extended in future to other previous, contemporaneous as well as Roman sites

The Polychrome Sinopia of Roman Mosaic at Lod (Israel): Pigments Characterization and Microstratigraphic Study

This paper presents the results of the archaeometric study on the pigments and the painting techniques used to produce the polichrome sinopia found under the tesserae of the Roman mosaic at Lod (Israel). The red, yellow, green and black paints, laying on the sovranucleus of the preparation mortar under the mosaic, were studied by polarised light microscopy on disperse pigments (PLM), reflected light microscopy (RLM), scanning electron microscopy (SEM) and X-ray powder diffraction (XRPD). The palette comprises red and yellow ochre, cinnabar, green earth and carbon black. The microstratigraphic analysis shows the presence of a carbonation layer including the pigment particles on the top of the mortars, indicating that the pigments were laid on a fresh mortar, according to a fresco technique.Department of Geosciences, University of Padova, Via Gradenigo 6, 35131 Padova, Italy, Art Conservation Department, Israel Antiquities Authority

Network Structures from Selection Principles

We present an analysis of the topologies of a class of networks which are optimal in terms of the requirements of having as short a route as possible between any two nodes while yet keeping the congestion in the network as low as possible. Strikingly, we find a variety of distinct topologies and novel phase transitions between them on varying the number of links per node. Our results suggest that the emergence of the topologies observed in nature may arise both from growth mechanisms and the interplay of dynamical mechanisms with a selection process.Comment: 4 pages, 5 figure

Prescription-induced jump distributions in multiplicative Poisson processes

Generalized Langevin equations (GLE) with multiplicative white Poisson noise pose the usual prescription dilemma leading to different evolution equations (master equations) for the probability distribution. Contrary to the case of multiplicative gaussian white noise, the Stratonovich prescription does not correspond to the well known mid-point (or any other intermediate) prescription. By introducing an inertial term in the GLE we show that the Ito and Stratonovich prescriptions naturally arise depending on two time scales, the one induced by the inertial term and the other determined by the jump event. We also show that when the multiplicative noise is linear in the random variable one prescription can be made equivalent to the other by a suitable transformation in the jump probability distribution. We apply these results to a recently proposed stochastic model describing the dynamics of primary soil salinization, in which the salt mass balance within the soil root zone requires the analysis of different prescriptions arising from the resulting stochastic differential equation forced by multiplicative white Poisson noise whose features are tailored to the characters of the daily precipitation. A method is finally suggested to infer the most appropriate prescription from the data

Petrographic & microstratigraphic analysis of mortar-based building materials from the Temple of Venus, Pompeii.

Recipes for mortar-based building materials may change over time and differ in various construction and restoration phases. They normally reflect craftsmen’s knowledge, availability of raw materials, and also the importance of the building in which they are found. The present research focuses on mortar-based materials from several construction and renovation phases of the Temple of Venus, at Pompeii, Italy, in order to identify any changes over time in production recipes

Conformations of Proteins in Equilibrium

We introduce a simple theoretical approach for an equilibrium study of proteins with known native state structures. We test our approach with results on well-studied globular proteins, Chymotrypsin Inhibitor (2ci2), Barnase and the alpha spectrin SH3 domain and present evidence for a hierarchical onset of order on lowering the temperature with significant organization at the local level even at high temperatures. A further application to the folding process of HIV-1 protease shows that the model can be reliably used to identify key folding sites that are responsible for the development of drug resistance .Comment: 6 pages, 3 eps figure

Finite Size Scaling Analysis of Biased Diffusion on Fractals

Diffusion on a T fractal lattice under the influence of topological biasing fields is studied by finite size scaling methods. This allows to avoid proliferation and singularities which would arise in a renormalization group approach on infinite system as a consequence of logarithmic diffusion. Within the scheme, logarithmic diffusion is proved on the basis of an analysis of various temporal scales such as first passage time moments and survival probability characteristic time. This confirms and puts on firmer basis previous renormalization group results. A careful study of the asymptotic occupation probabilities of different kinds of lattice points allows to elucidate the mechanism of trapping into dangling ends, which is responsible of the logarithmic time dependence of average displacement.Comment: 17 pages TeX, 3 Postscript figure

Mapping of stones and their deterioration forms : the Clock Tower, Venice (Italy)

The HYPERION EU project aims to develop a Decision Support System to improve resilience and sustainable reconstruction of historic areas faced with climate change and extreme events. In this context, Venice presents an outstanding example of urban and architectural complexity and richness. The mapping of the ornamental stones of the facade of the Venice Clock Tower (Torre dell'Orologio) and their deterioration patterns acts as a milestone on which to build the knowledge-acquisition process of the system as regards stone artefacts and their decay products. The Clock Tower is an early Renaissance building (1499) in Lombardesque style and stands over the entrance to the Mercerie on the northern side of St. Mark's Square. Detailed surveys and mapping of both building materials (mainly stones) and deterioration patterns were carried out, the latter following the glossary of weathering forms, coupled with an easy-to-use scale of evaluation of their intensity. The data output consists of several monothematic maps which can be handled separately, each one focusing on precise lithological or specific deterioration aspects. This study also proposes a simple approach to summarizing the total state of deterioration of the building in the form of a Total Deterioration Rank (TDR) and its representation. The stones used in the facade are regional (Ammonitico Rosso and Scaglia Rossa) and extra-regional limestones (Istrian Stone), as well as Mediterranean white and coloured marbles and stones already used in antiquity (i.e., Fior di Pesco or marmor chalcidicum, lapis porphyrites, a volcanic rock from the Egyptian Eastern Desert, Proconnesian marble from the Island of Marmara, Pavonazzetto toscano and white Carrara marble from the Italian Apuan Alps). The most frequent forms of deterioration detected are black crusts, patinas, discoloration and patterns linked to erosion processes. The interrelation of different mappings led to a number of useful considerations concerning differences in the effectiveness of maintenance procedures between public and private management of the monument

Roundoff-induced Coalescence of Chaotic Trajectories

Numerical experiments recently discussed in the literature show that identical nonlinear chaotic systems linked by a common noise term (or signal) may synchronize after a finite time. We study the process of synchronization as function of precision of calculations. Two generic behaviors of the average coalescence time are identified: exponential or linear. In both cases no synchronization occurs if iterations are done with {\em infinite} precision.Comment: 6 pages, 3 postscript figures, to be published in Phys. Rev.