Seismic Vulnerability of the Italian Roadway Bridge Stock

This study focuses on the seismic vulnerability evaluation of the Italian roadway bridge stock, within the framework of a Civil Protection sponsored project. A comprehensive database of existing bridges (17,000 bridges with different level of knowledge) was implemented. At the core of the study stands a procedure for automatically carrying out state-of-the-art analytical evaluation of fragility curves for two performance levels – damage and collapse – on an individual bridge basis. A webGIS was developed to handle data and results. The main outputs are maps of bridge seismic risk (from the fragilities and the hazard maps) at the national level and real-time scenario damage-probability maps (from the fragilities and the scenario shake maps). In the latter case the webGIS also performs network analysis to identify routes to be followed by rescue teams. Consistency of the fragility derivation over the entire bridge stock is regarded as a major advantage of the adopted approach

A comparison of seismic risk maps for Italy

National seismic risk maps are an important risk mitigation tool as they can be used for the prioritization of regions within a country where retrofitting of the building stock or other risk mitigation measures should take place. The production of a seismic risk map involves the convolution of seismic hazard data, vulnerability predictions for the building stock and exposure data. The seismic risk maps produced in Italy over the past 10 years are compared in this paper with recent proposals for seismic risk maps based on state-of-the-art seismic hazard data and mechanics-based vulnerability assessment procedures. The aim of the paper is to open the discussion for the way in which future seismic risk maps could be produced, making use of the most up-to-date information in the fields of seismic hazard evaluation and vulnerability assessment

Mappe di rischio sismico a scala nazionale con dati aggiornati sulla pericolosità sismica di base e locale

Le mappe di rischio sismico nazionale rappresentano un importante strumento per la sua mitigazione e possono essere utilizzate nella valutazione delle priorità di intervento per la messa in sicurezza degli edifici. La realizzazione di queste mappe è possibile valutando la pericolosità sismica, la vulnerabilità per le diverse classi di edifici presenti sul territorio italiano e l’esposizione. In questo articolo, oltre a presentare le nuove mappe di rischio sismico per l’Italia si vuole analizzare l’influenza del fattore di amplificazione litostratigrafica sui risultati ottenuti, mettendo a confronto le mappe di rischio che sono state sviluppate utilizzando sia i fattori di amplificazione litostratigrafica previsti dall’OPCM n°3274 che quelli previsti dalle NTC08. Inoltre, in modo innovativo rispetto agli studi condotti in Italia negli ultimi 10 anni, vengono considerate curve analitiche di vulnerabilità e valori di pericolosità sismica basati sugli spettri di accelerazione

Basal and IL-1β enhanced chondrocyte chemotactic activity on monocytes are co-dependent on both IKKα and IKKβ NF-κB activating kinases

IKKα and IKKβ are essential kinases for activating NF-κB transcription factors that regulate cellular differentiation and inflammation. By virtue of their small size, chemokines support the crosstalk between cartilage and other joint compartments and contribute to immune cell chemotaxis in osteoarthritis (OA). Here we employed shRNA retroviruses to stably and efficiently ablate the expression of each IKK in primary OA chondrocytes to determine their individual contributions for monocyte chemotaxis in response to chondrocyte conditioned media. Both IKKα and IKKβ KDs blunted both the monocyte chemotactic potential and the protein levels of CCL2/MCP-1, the chemokine with the highest concentration and the strongest association with monocyte chemotaxis. These findings were mirrored by gene expression analysis indicating that the lowest levels of CCL2/MCP-1 and other monocyte-active chemokines were in IKKαKD cells under both basal and IL-1β stimulated conditions. We find that in their response to IL-1β stimulation IKKαKD primary OA chondrocytes have reduced levels of phosphorylated NFkappaB p65pSer536 and H3pSer10. Confocal microscopy analysis revealed co-localized p65 and H3pSer10 nuclear signals in agreement with our findings that IKKαKD effectively blunts their basal level and IL-1β dependent increases. Our results suggest that IKKα could be a novel OA disease target

MICROZONATION STUDY FOR AN INDUSTRIAL SITE IN SOUTHERN ITALY

A microzonation study for an industrial area located in Sicily (southern Italy) has been carried out through anintegrated approach using GIS and modelling tools for subsurface geology, together with procedures for soilresponse estimation. The seismic input was provided by an updated seismic hazard analysis aimed at betterdefining and characterizing the seismogenic sources active in the region. The approach involved thedevelopment of a model of the subsurface geology through the interpretation of several borehole data comingfrom industrial or private wells records. The lithologies described in the borehole logs were reclassified according to main litotechnical units for which seismological properties were available from previous studies.The reclassified logs were then interpreted using the GSI3D software (Geological Surveying and Investigation in3 Dimensions), which allows to draw and cross-correlate geological sections over the whole study area, toproduce 3D surfaces which model the topography of each litotechnical unit at depth. The model was thenimported into a GIS and linked to a customised version of SHAKE91 for the estimation of 1D soil response at a grid of points. Maps of amplification factors for different periods of engineering interest have been produced.The methodology used in this work has produced a dynamic tool which allows an easy update of themicrozonation maps as new data become available, since both the subsurface model and the litotechnical unitsparameters can be quickly updated and new analyses run

On the fluctuations of jamming coverage upon random sequential adsorption on homogeneous and heterogeneous media

The fluctuations of the jamming coverage upon Random Sequential Adsorption (RSA) are studied using both analytical and numerical techniques. Our main result shows that these fluctuations (characterized by $\sigma_{\theta_J}$) decay with the lattice size according to the power-law $\sigma_{\theta_J} \propto L^{-1/ \nu}$. The exponent $\nu$ depends on the dimensionality $D$ of the substrate and the fractal dimension of the set where the RSA process actually takes place ($d_f$) according to $\nu = 2 / (2D - d_f)$.This theoretical result is confirmed by means of extensive numerical simulations applied to the RSA of dimers on homogeneous and stochastic fractal substrates. Furthermore, our predictions are in excellent agreement with different previous numerical results. It is also shown that, studying correlated stochastic processes, one can define various fluctuating quantities designed to capture either the underlying physics of individual processes or that of the whole system. So, subtle differences in the definitions may lead to dramatically different physical interpretations of the results. Here, this statement is demonstrated for the case of RSA of dimers on binary alloys.Comment: 20 pages, 8 figure

Van Hove singularity and spontaneous Fermi surface symmetry breaking in Sr3Ru2O7

The most salient features observed around a metamagnetic transition in Sr3Ru2O7 are well captured in a simple model for spontaneous Fermi surface symmetry breaking under a magnetic field, without invoking a putative quantum critical point. The Fermi surface symmetry breaking happens in both a majority and a minority spin band but with a different magnitude of the order parameter, when either band is tuned close to van Hove filling by the magnetic field. The transition is second order for high temperature T and changes into first order for low T. The first order transition is accompanied by a metamagnetic transition. The uniform magnetic susceptibility and the specific heat coefficient show strong T dependence, especially a log T divergence at van Hove filling. The Fermi surface instability then cuts off such non-Fermi liquid behavior and gives rise to a cusp in the susceptibility and a specific heat jump at the transition temperature.Comment: 11 pages, 4 figure

Quantum Criticality

This is a review of the basic theoretical ideas of quantum criticality, and of their connection to numerous experiments on correlated electron compounds. A shortened, modified, and edited version appeared in Physics Today. This arxiv version has additional citations to the literature.Comment: 17 pages, 7 figures; (v2) added ref

Broken rotational symmetry in the pseudogap phase of a high-Tc superconductor

The nature of the pseudogap phase is a central problem in the quest to understand high-Tc cuprate superconductors. A fundamental question is what symmetries are broken when that phase sets in below a temperature T*. There is evidence from both polarized neutron diffraction and polar Kerr effect measurements that time- reversal symmetry is broken, but at temperatures that differ significantly. Broken rotational symmetry was detected by both resistivity and inelastic neutron scattering at low doping and by scanning tunnelling spectroscopy at low temperature, but with no clear connection to T*. Here we report the observation of a large in-plane anisotropy of the Nernst effect in YBa2Cu3Oy that sets in precisely at T*, throughout the doping phase diagram. We show that the CuO chains of the orthorhombic lattice are not responsible for this anisotropy, which is therefore an intrinsic property of the CuO2 planes. We conclude that the pseudogap phase is an electronic state which strongly breaks four-fold rotational symmetry. This narrows the range of possible states considerably, pointing to stripe or nematic orders.Comment: Published version. Journal reference and DOI adde