Excised acoustic black holes: the scattering problem in the time domain

The scattering process of a dynamic perturbation impinging on a draining-tub model of an acoustic black hole is numerically solved in the time domain. Analogies with real black holes of General Relativity are explored by using recently developed mathematical tools involving finite elements methods, excision techniques, and constrained evolution schemes for strongly hyperbolic systems. In particular it is shown that superradiant scattering of a quasi-monochromatic wavepacket can produce strong amplification of the signal, offering the possibility of a significant extraction of rotational energy at suitable values of the angular frequency of the vortex and of the central frequency of the wavepacket. The results show that theoretical tools recently developed for gravitational waves can be brought to fruition in the study of other problems in which strong anisotropies are present.Comment: 8 pages, 9 figure

Design of Wireless Sensor Nodes for Structural Health Monitoring applications

Enabling low-cost distributed monitoring, wireless sensor networks represents an interesting solution for the implementation of structural health monitoring systems. This work deals with the design of wireless sensor networks for health monitoring of civil structures, specifically focusing on node design in relation to the requirements of different structural monitoring application classes. Design problems are analysed with specific reference to a large-scale experimental setup (the long-term structural monitoring of the Basilica S. Maria di Collemaggio, L’Aquila, Italy). Main limitations emerged are highlighted, and adopted solution strategies are outlined, both in the case of commercial sensing platform and of full custom solutions

The autoinflammatory diseases.

Summary The monogenic autoinflammatory syndromes are conditions caused by mutations of genes coding for proteins that play a pivotal role in the regulation of the inflammatory response. Due to their genetic nature, most of these disorders have an early onset. Clinically they are characterised by recurrent flares of systemic inflammation presenting most of the time as sudden fever episodes associated with elevation of acute phase reactants and with a number of clinical manifestations such as rash, serositis, lymphadenopathy and arthritis. Symptom-free intervals are characterised by complete wellbeing, normal growth and complete normalisation of acute phase reactants. Familial Mediterranean fever (FMF), mevalonate-kinase deficiency (MKD) and tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) are the three monogenic disorders subsumed under the term periodic fevers, while a systemic inflammation dominated by a characteristic urticarial rash associated with a number of other clinical manifestations is typical of familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and chronic infantile neurological cutaneous and articular syndrome (CINCA). These diseases represent the clinical spectrum of different mutations of a gene named cold-induced autoinflammatory syndrome 1 (CIAS-1, or NLRP3) coding for a protein called cryopyrin. Hence these disorders are also known as cryopyrin-associated periodic syndromes (CAPS). Other conditions are characterised by typical granulomatous formations (granulomatous disorders). Blau's syndrome (familial juvenile systemic granulomatosis) presents with non-caseating granulomatous inflammation affecting the joint, skin, and uveal tract (the triad of arthritis, dermatitis and uveitis) and is associated with mutations of the NACHT domain of the gene CARD15 (or NOD2)

Monitoring of Rain-Induced Landslides for the Territory Protection: The AD-VITAM Project

The authors refer in this paper some of the analyses already done and the planned activities in developing the AD-VITAM Project (InterReg V-A France \u2013 Italy \u2013 E.U. ALCOTRA), which aims to assess the most suitable techniques to obtain a reliable forecasting of rain-induced landslides, in order to enhance the territorial resilience when subject to such a risk. The authors refers about the procedure called LAMP (Landslides Monitoring and Predicting), consisting in an Integrated Hydrological/Geotechnical numerical model (IHG) fed by site-specific installed sensor-network, to help in the start-up calibration of some of the relevant parameters used by the model. The tuned-up simulation models is used to assess the landslide susceptibility to measured/predicted rainfall histories. The implementation of the numerical geotechnical/hydrological models on a GIS platform with regard to some of the selected sites, and the preliminary tests performed on the sensors to be installed on-site in order to monitor the real-time response to rainfalls are briefly described. Thanks to the effective cooperation with the local technicians and the project partners, the final achievements of AD-VITAM could furnish a real support to a better protection of both the natural and the urbanized environments, allowing site-specific warnings and a better hydro-geological risk management capacity

Oscillation of water table due to rainfall: an experience of modeling in GIS

A physically-based Integrated Hydrological-Geotechnical model (IHG) able to assess the rainfallinduced landslide susceptibility was developed, refined and applied in GIS environment along the past years (Passalacqua, 2002; Federici et al., 2014; Bovolenta et al., 2016), showing its reliability. It is a useful instrument to landslide susceptibility evaluations and land-use planning over wide areas. The present paper focuses on the modeling of water table oscillation due to rainfall, comparing different hydrological models

Variable stars and stellar populations in Andromeda XXI: II. Another merged galaxy satellite of M31?

B and V time-series photometry of the M31 dwarf spheroidal satellite Andromeda XXI (And XXI) was obtained with the Large Binocular Cameras at the Large Binocular Telescope. We have identified 50 variables in And XXI, of which 41 are RR Lyrae stars (37 fundamental-mode RRab, and 4 first-overtone RRc, pulsators) and 9 are Anomalous Cepheids (ACs). The average period of the RRab stars ( = 0.64 days) and the period-amplitude diagram place And~XXI in the class of Oosterhoff II - Oosterhoff-Intermediate objects. From the average luminosity of the RR Lyrae stars we derived the galaxy distance modulus of (m-M)$_0$=$24.40\pm0.17$ mag, which is smaller than previous literature estimates, although still consistent with them within 1 $\sigma$. The galaxy color-magnitude diagram shows evidence for the presence of three different stellar generations in And~XXI: 1) an old ($\sim$ 12 Gyr) and metal poor ([Fe/H]=$-$1.7 dex) component traced by the RR Lyrae stars; 2) a slightly younger (10-6 Gyr) and more metal rich ([Fe/H]=$-$1.5 dex) component populating the red horizontal branch, and 3) a young age ($\sim$ 1 Gyr) component with same metallicity, that produced the ACs. Finally, we provide hints that And~XXI could be the result of a minor merging event between two dwarf galaxies.Comment: accepted for publications in Ap

LANDSLIDE SUSCEPTIBILITY ASSESSMENT: SOIL MOISTURE MONITORING DATA PROCESSED BY AN AUTOMATIC PROCEDURE IN GIS FOR 3D DESCRIPTION OF THE SOIL SHEAR STRENGTH

Abstract. Slope stability is strongly influenced by soil hydraulic conditions. Considering rain-triggered shallow landslides, the stability can be markedly influenced by the propagation of the saturation front inside the unsaturated zone. Soil shear strength varies in the vadose zone depending on the type of soil and the variations of soil moisture. Monitoring of the unsaturated zone can be done by measuring volumetric water content using low-cost instrumentation, such as capacitive sensors that are easy to manage and provide data in near-real time. For a proper soil moisture assessment a laboratory soil-specific calibration of the sensors is recommended. Knowing the soil water content, the suction parameter can be estimated by a Water Retention Curve (WRC), and consequently the soil shear strength in unsaturated conditions is evaluated. Several models are already proposed for shallow landslide susceptibility evaluation, also in FOSS GIS environment. However, these models do not usually consider the soil shear strength in unsaturated conditions, even if it is crucial, especially in the case of shallow landslides. A procedure that allows the estimate of the soil shear strength starting from soil moisture monitoring data (from sensor networks or satellite-derived map) is here presented. Moreover, preliminary results relative to a case study (i.e. the landslide of Ceriana-Mainardo in Italy) are shown. The proposed procedure could be integrated into existing models for landslide susceptibility assessment and also for the emergency management