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An ambient noise HVSR survey in Valletta World Heritage Site and the historical city of Mdina, Malta
In this paper we report the preliminary results of the measurements of ambient noise on a dense network of measurement sites in and around the cities of Valletta and Mdina; two important historical heritage sites in Malta. The city of Valletta is the present capital of Malta and it is inextricably linked to the history of the military and charitable Order of St John of Jerusalem. ; N/A
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Experimental evaluation of the thermal polarization in direct contact membrane distillation using electrospun nanofiber membranes doped with molecular probes
Sergio Santoro acknowledges the European Commission for the financial support: The Education, Audiovisual and Culture Executive Agency (EU-EACEA) within the EUDIME Erasmus Mundus Doctorate in Membrane Engineering program (FPA 2011-0014, SGA 2012-1719, Edition II, http://eudime.unical.it). Ivan Moreno acknowledges the PhD grant from the Aragon Government, DGA, reference B008/12. ; Membrane distillation (MD) has recently gained considerable attention as a valid process for the production of fresh-water due to its ability to exploit low grade waste heat for operation and to ensure a nearly feed concentration-independent production of high-purity distillate. Limitations have been related to polarization phenomena negatively affecting the thermal efficiency of the process and, as a consequence, its productivity. Several theoretical models have been developed to predict the impact of the operating conditions of the process on the thermal polarization, but there is a lack of experimental validation. In this study, electrospun nanofiber membranes (ENMs) made of Poly(vinylidene fluoride) (PVDF) and doped with (1, 10-phenanthroline) ruthenium (II) Ru(phen) 3 were tested at different operating conditions (i.e., temperature and velocity of the feed) in direct contact membrane distillation (DCMD). The temperature sensitive luminophore, Ru(phen) 3 , allowed the on-line and non-invasive mapping of the temperature at the membrane surface during the process and the experimental evaluation of the effect of the temperature and velocity of the feed on the thermal polarization. ; publishersversion ; published
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When probabilistic seismic hazard climbs volcanoes: the Mt. Etna case, Italy – Part 2: Computational implementation and first results
In: Natural hazards and earth system sciences: NHESS, Band 17, Heft 11, S. 1999-2015
ISSN: 1684-9981
Abstract. This paper describes the model implementation and presents results of a probabilistic seismic hazard assessment (PSHA) for the Mt. Etna volcanic region in Sicily, Italy, considering local volcano-tectonic earthquakes. Working in a volcanic region presents new challenges not typically faced in standard PSHA, which are broadly due to the nature of the local volcano-tectonic earthquakes, the cone shape of the volcano and the attenuation properties of seismic waves in the volcanic region. These have been accounted for through the development of a seismic source model that integrates data from different disciplines (historical and instrumental earthquake datasets, tectonic data, etc.; presented in Part 1, by Azzaro et al., 2017) and through the development and software implementation of original tools for the computation, such as a new ground-motion prediction equation and magnitude–scaling relationship specifically derived for this volcanic area, and the capability to account for the surficial topography in the hazard calculation, which influences source-to-site distances. Hazard calculations have been carried out after updating the most recent releases of two widely used PSHA software packages (CRISIS, as in Ordaz et al., 2013; the OpenQuake engine, as in Pagani et al., 2014). Results are computed for short- to mid-term exposure times (10 % probability of exceedance in 5 and 30 years, Poisson and time dependent) and spectral amplitudes of engineering interest. A preliminary exploration of the impact of site-specific response is also presented for the densely inhabited Etna's eastern flank, and the change in expected ground motion is finally commented on. These results do not account for M > 6 regional seismogenic sources which control the hazard at long return periods. However, by focusing on the impact of M < 6 local volcano-tectonic earthquakes, which dominate the hazard at the short- to mid-term exposure times considered in this study, we present a different viewpoint that, in our opinion, is relevant for retrofitting the existing buildings and for driving impending interventions of risk reduction.