Study of the solar signal in mean Central Europe temperature series from 1760 to 1998

We used a new series, highly reliable and representing the mean surface temperature of Central Europe for the period 1760-1998, to study Sun-Climate relationships. The results indicate that the influence of solar activity is evident only on a long time scale, in particular for the period 1860-present. On a short time scale it is not directly evident. From the spectral analysis we deduced that the strength of solar signal in the temperature series has an intermittent behaviour. We proposed a mechanism of resonance between the two non-linear systems, the Sun and Earth climate, to explain our results

Simulation of Shaking Table Tests to Study Soil-Structure Interaction by Means of Two Different Constitutive Models

The paper presents the main results of a FEM 3-D model reproducing a physical model subjected to shaking table tests. The tests, performed at the EERC laboratory of Bristol University, have been simulated by means of a new numerical model based on a recent constitutive model characterized by isotropic and kinematic hardening and devoted to granular soil. The shaking table tests have been performed using: a six-degree of freedom shaking table; a shear-stack; a scaled one-storey steel frame; the Leigthon Buzzard Sand. The tests have been characterized by 11 shaking runs. As regards the 3-D numerical modeling, the linear elastic material has been considered for the structure, instead the soil has been modeled both with a cap-hardening Drucker-Prager model, often implemented in commercial codes, and with the above mentioned new constitutive model, implemented in the utilized FEM code by the Research Group of Catania University. Thanks to the great quantity of experimental data, the power of the proposed numerical model in simulation/prediction of dynamic soil-structure interaction can be verified and compared with the capability of other numerical models based on simpler constitutive models

Experimental, Theoretical and Numerical Evaluation of the Stiffness of a Soil-Foundation Model by Shaking-Table Test

A well-controlled test was carried out on a Leighton Buzzard sand-shallow foundation system by means of the six-degree-of-freedom shaking table available at the University of Bristol. The foundation consists of a concrete block located into a flexible shear-stack (Taylor et al., 1994) filled up to 1.00 m with the sand. During the test the block was subjected to a centered vertical load and to one direction sine dwell-type acceleration applied at the base of the shear stack. The static and dynamic sand properties were evaluated through different laboratory tests, among them resonant column tests, cyclic and monotonic loading torsional shear tests were performed (Mazzarella, 1999). A comprehensive network of accelerometers and displacement transducers was used to check the static and dynamic soil-foundation interaction (Maugeri et al., 1999a). The impedance functions (Gazetas, 1991) were evaluated and then compared with the experimental results. Finally, the experimental results were compared with the numerical ones obtained by means of a FEM code (Massimino, 1999) developed at the University of Catania

Mathematical modelling of the landslide occurred at Gagliano Castelferrato (Italy)

International audienceShallow slopes in clayey colluvial covers are often involved in progressive downhill motion with discontinuous rate of movements, depending on fluctuations in pore-water pressure. In geotechnical engineering research on natural slopes, the main efforts have been concentrated on stability analysis, always with a rigid perfectly plastic body assumption. In case of slow slope movements, however, the notion of stability losses its sense, so the main question is not to evaluate a stability factor, but to model a velocity field and to define the kinematic and dynamic features of the movement (mobility analysis). Many authors, in their researches, deal with slow slope movements and for the complexity of the problem and the great number of parameters involved they agree about applying numerical techniques (FEM, FDM) and advanced material modelling (elastoviscoplasticity) and suggest to calibrate the involved parameters values with the help of ''back analyses'' of existing case histories. In this paper a mathematical model predicting the landslide body viscous deformations, is presented. The model has been implemented in a computer FDM code, and has been tested on some well known case histories. Here it is applied to the case of a landslide occurred at Gagliano Castelferrato (Sicily ? Italy), where a great number of field measurements was available

Reconstruction of daily pressure maps over Italy during some extreme events of the 19th Century

The quality and availability of daily meteorological data for the reconstruction of atmospheric circulation over Italy in the period between the Italian political Unity (1860) and the development of the Central Office for Meteorology (1879) is studied. Examples of atmospheric circulation reconstructed for some extreme events are presented

1961–1990 monthly high-resolution solar radiation climatologies for Italy

Abstract. We present a methodology for estimating solar radiation climatologies from a sparse network of global radiation and/or sunshine duration records: it allows to obtain high-resolution grids of monthly normal values for global radiation (and for the direct and diffuse components), atmospheric turbidity, and surface absorbed radiation. We discuss the application of the methodology to a preliminary version of an Italian global radiation and sunshine duration data set, which completion is still in progress and present the resulting 1961–1990 monthly radiation climatologies

Extreme summer temperatures in Western Europe

Abstract. We discuss the evolution of summer temperature extremes over Western Europe during 1961–2004 in the context of current climate warming. Using a parametric approach, we investigate the role of properties and changes in probability density functions of daily temperatures in modifying the frequency of severe, isolated events. In this perspective, the recent intensification of extremely warm events over Europe turns out to be well consistent with a pure, nonuniform shift of mean values, with no room for conjectures about increasing temperature variability

Radical photoinduced cationic frontal polymerization in porous media

Two different interpenetrating phase composites were produced using a radical photoinduced cationic frontal polymerization process. The composites were based on polyurethane (PU) and aluminium open-cell foams impregnated with a formulation of a cycloaliphatic epoxy with different concentrations of a cationic photoinitiator and a thermal initiator. The influence of both types of initiators on the frontal polymerization features was systematically evaluated for the PU foam. It was found to occur only when the concentration of both initiators was greater than 0.5 wt%, leading to full conversion of the epoxy in the whole volume of the 15 mm thick composite samples within less than 100 s. The maximum temperature reached by the propagation front was in the range 275–305 °C depending on the type of formulation, leading to pores in the epoxy phase and extensive degradation of the PU phase. In the case of the opaque aluminium foam, an additional layer of pure resin was required on the UV-exposed surface, which corresponded to a critical mass of a few grams to ensure sufficient heat generation and trigger the front propagation. © 2020 Society of Chemical Industry