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Earthquakes produce on infills In-Plane (IP) and Out-Of-Plane (OOP) actions. The recent earthquakes have proved that the OOP collapse of infills is a diffused mechanism also in buildings designed to resist to seismic events in agreement to the most modern strategies. This fact makes the question arises about the safety of infills with respect OOP actions. The strong interaction between IP and OOP behaviour of infills traduces in a progressively reduction of the OOP strength. Further, only in few cases codes suggest adequate strategies to face this issue. For what above, in the paper the reduction of OOP strength because of the IP damage is studied by an extended numerical experimental campaign based on FE models to be considered as complementary to the very few laboratory experimental tests available in the literature.

In the last decades many strategies for seismic vulnerability mitigation of structures have been developed through analytical studies and experimental tests. Among these, energy dissipation by external devices assumes a great relevance for the relative design simplicity, even if applied to complex structures, and the effectiveness in reducing seismic demand. In particular, the use of fluid viscous dampers represents a very attractive solution because of their velocity-dependent behaviour and relatively low costs. The application on structures requires specific study under seismic excitation and a particular care of structural details. In this context the use of proper constitutive models for the dampers assumes a fundamental role. Seismic codes, as well as literature models generally provide a velocity-dependent relationship with two characteristic constants defining the shape of the force-displacement curve. In this paper an experimental campaign aimed at the determination of the damper constants in the range of low velocities is presented. A fluid viscous damper is tested with different ramp velocity functions. Results show that the assumption of velocity independence of the damper constants fails for the case of low velocity, giving rise to new issues about the limit of validity of the constitutive models generally adopted for viscous dampers.

The purple starfish Ophidiaster ophidianus is an Atlanto-Mediterranean starfish protected under the EU’s Habitats Directive. Despite the wide distribution and the current range expansion of this warm affinity species in the northern Mediterranean areas, nothing is known about its diet. Using field observations and carbon (δ13C) and nitrogen (δ15N) stable isotopes, we explored possible changes in density and diet of O. ophidianus in relation to two different Mediterranean habitats: the coralline barren and the macro algae forest. Data were collected at the Marine Protected Area of Ustica Island (Southern Tyrrhenian Sea) from June to September 2009. Starfish density was not affected by the habitat, while on the contrary the diet of O. ophidianus was significantly different between barren and macro algae forest habitat. O. ophidianus fed mainly on crustose algae and bryozoans in barren, whereas it preferred the sponge Ircinia spp. in the forested habitat. Other food sources such as small gastropods and sedimentary organic matter were selected by this starfish. In general O. ophidianus showed a short niche breadth and omnivory habits with tendency to carnivory.

Marine protected areas (MPAs), when designated correctly and managed well, provide a plethora of conservation benefits for current and future generations (i.e. increased habitat heterogeneity at the seascape level, increased abundance of threatened species and habitats, and maintenance of a full range of genotypes). The distribution pattern of an important target species from the Mediterranean Sea, the parrotfish Sparisoma cretense, was determined in the Plemmirio MPA (Siracuse, Italy) during summer of 2014. Sampling was carried out by means of underwater visual census techniques at two different depth (0/10 m and 10/20 m respectively) at four sampling sites within the reserve boundaries and two sites outside the reserve. Densities and biomasses of S. cretense were significantly higher inside than outside the MPA, however no differences in depth were detected. Our findings confirm that the enforcement of the Plemmirio MPA has a strong positive effect in retaining high numbers of commercially important species, such as S. cretense.

Ecosystem resistance to species invasion is considered to be related to the abundance and diversity of native species (i.e. diversity-resistance hypothesis). In particular, the integrity of predator assemblages may enhance the control of prey populations through direct and indirect interactions (e.g.: different predation strategies by different predators, facilitative interactions among predators). Depletion of predators due to overfishing is therefore expected to enhance the abundance and ultimately the spread of alien prey species. Manipulative field experiments were performed to evaluate the effects of different abundance and diversity of predator assemblages on the invasion success of the alien crab Percnon gibbesi. The experiments were conducted in northwestern Sicily (Italy, Mediterranean Sea), in summer 2015, on bare rocky boulders, the habitat preferred by P. gibbesi. The study sites were characterized by significantly different species richness and abundance of the potential predators of P. gibbesi. Predation rate of different predator assemblages was assessed by means of tethering experiments on the alien crab. As predicted, predation rate on P. gibbesi resulted significantly higher in sites characterized by higher predator abundance and species richness than in sites with lower values. Our findings, although restricted to small spatial scales, support the diversity resistance hypothesis, revealing a negative relationship between the diversity of predator assemblages and the invasiveness (average abundance) of the alien species P. gibbesi.

Electro-Discharge machining (EDM) is a thermal process comprising a complex metal removal mechanism, which involves the formation of a plasma channel between the tool and the workpiece electrodes leading to the melting and evaporation of the material to be removed. EDM is considered especially suitable for machining complex contours with high accuracy, as well as for materials that are not amenable to conventional removal methods. However, several phenomena negatively affecting the surface integrity of EDMed workpieces need to be taken into account and studied in order to achieve the optimization of the process. Recently, artificial neural networks (ANN) have emerged as a novel modeling technique capable to provide reliable results and readily integrated into a lot of technological areas. In this paper, ANN models for the prediction of the mean surface roughness of electro-discharge machined surfaces are presented. The comparison of the derived results with experimental findings demonstrates the promising potential of using back propagation neural networks (BPNNs) for the reliable and robust approximation of the Surface Roughness of Electro-discharge Machined Components.

Simplified equations aimed at evaluating the flexural and shear capacity of corroded R.C. beams are presented and discussed in this paper, with reference to ordinary beams reinforced both longitudinally (with same-size bars) and transversely (with stirrups). A model is developed to take care of diffused and localised corrosion (pitting corrosion), concrete decay in compression and bond-strength decay at concrete-reinforcement interface. A fairly innovative contribution of this study is the introduction into the proposed equations of the main parameters governing the corrosion processes. The proposed approach is simple and effective, and may be adopted in the assessment of many damaged structures (a) on the basis of the available experimental information (e.g., carbonation depth, chloride content, pit depth and size in the bars and mass loss in the reinforcement), and (b) by utilizing analytical expressions calibrated through the knowledge of the density of the corrosion current.

The recent large use of nonlinear seismic assessment techniques requires the definition of highly reliable computational models. The retrofitting or strengthening of RC columns by steel angles and battens is a commonly adopted technique, used to improve strength and deformation capacity of existing RC buildings. In the case of steel angles not directly loaded, the numerical definition of the cross-section model has to be handled carefully since it is affected by more uncertainties. The vertical load carried by the angles is a function of the lateral confinement pressure, the cohesion and the friction coefficient between the materials, parameters which are not always easy to predict. The paper discusses the numerical implementation in OpenSees of RC jacketed sections models, giving practical solutions to properly account for the above mentioned issues. In order to validate the predictive capacity of the model, the numerical results are compared with the outcomes of an experimental campaign carried out by the authors. Some final modelling remarks are given by the observation of the results of experimental tests and numerical simulations

Asteroids are an important group of predators in many marine ecosystems. The measure of body size is crucial in studying asteroid biology as this variable affects both prey selection and predation impact. Current field techniques for estimating asteroid size (i.e. total length TL, total weight TW) include the measure of correlated variables, such us the central disk (CD) and arm length (AL). However, these variables are often time-consuming and require a direct handling of the organism. We tested the accuracy of new asteroid body metrics, the arm height (AH) or arm width (AW), to rapidly estimate body size in asteroids. AH and AW were measured in three of the most common Mediterranean asteroids (Marthasterias glacialis, Ophidiaster ophidianus and Coscinasterias tenuispina), sampled from April to August 2008, along the coasts of Ustica Island off the northern coast of Sicily. We used both linear and exponential regression analyses to compare the performance of AH, AL, AW and CD in estimat- ing size for the three species studied. Results suggest that, in M. glacialis and C. tenuispina, AH is strongly correlated (p, peer-reviewed

La possibilità di individuare e quantificare le principali criticità legate ad eventi catastrofici naturali su un territorio, consente di pianificare strategie e interventi adeguati da parte degli organismi di Protezione Civile coinvolti in emergenze locali e internazionali. Il rischio sismico dipende soprattutto dalla vulnerabilità degli edifici appartenenti alle aree urbane. La conoscenza degli scenari di rischio è dunque fondamentale per pianificare e gestire azioni di assistenza in caso di emergenza e non può prescindere dalla quantificazione e localizzazione della vulnerabilità sismica. Il presente studio propone una procedura per la definizione di mappe di vulnerabilità sismica in termini di indici di vulnerabilità e PGA critiche con particolare riferimento ai piccoli e medi centri urbani delle aree mediterranee transfrontaliere. La procedura è stata testata sul centro urbano dell'isola di Lampedusa e si basa su una preliminare indagine storica dell'area urbana e delle principali caratteristiche formali e tecnologie degli edifici coinvolti. Gli indici di vulnerabilità sono valutati attraverso schede GNDT di secondo livello. Il modello di vulnerabilità, che consente la definizione delle curve di fragilità è infine calibrato sulla base indagini numericosperimentali condotte su un edifici prototipo significativamente rappresentativi dell'edificato urbano. Gli output forniscono, per l'area investigata, le mappe dell'indice di vulnerabilità e dei valori di PGA di primo danneggiamento e di collasso.

Biometric parameters of the Asteroid echinoderm Marthasterias glacialis (L.) were measured at Ustica Island MPA (SW Tyrrhenian Sea). Wet weight was correlated with tip-to-tip (arm-span) diameter, central disk, arm length, arm width and arm height. Results show high positive correlation between weight and arm height, suggesting a new useful method to estimate starfish size also for in situ measurements.

Reinforced concrete (RC) jacketing is a common method to retrofit existing columns with poor structural performance. It can be applied in two different ways: if the continuity of the jacket is ensured, the axial load of the column can be transferred to the jacket, which will be directly loaded; conversely, if no continuity is provided, the jacket induces only confinement action. In both cases the strength and ductility evaluation is rather complex, due to the different physical phenomena included, such as confinement, composite action core-jacket, preload, buckling of longitudinal bars. Although different theoretical studies have been carried out to calculate the confinement effects, a practical approach to evaluate the flexural capacity and ductility is still missing. The calculation of these quantities is often related to the use of commercial computer programs, taking advantage of numerical methods such as fiber method or finite element method. This paper presents a simplified approach to calculate the flexural strength and ductility of square RC jacketed sections subjected to axial load and bending moment. In particular the proposed approach is based on the calibration of the stress-block parameters including the confinement effect. Equilibrium equations are determined and buckling of longitudinal bars is modeled with a suitable stress-strain law. Moment-curvature curves are derived with simple calculations. Finally, comparisons are made with numerical analyses carried out with the code OpenSees and with experimental data available in the literature, showing good agreement.

10.1364/OME.4.002274 We studied laser generation of the Ho3+-ion in (Ho,Tm):KLu(WO4)2 crystals pumped by Ti:sapphire and diode lasers achieving output powers up to ~1.2 W. For polarization parallel to the Nm principal axis, the lasers operated at 2078 or 2059-1960 nm depending on the transmission of the output coupler. The maximum slope efficiency with respect to the absorbed power reached ~30% for both types of pump sources. Tuning was studied with Ti:sapphire laser pumping achieving a tuning range of ~180 nm.

The paper describes the erosion processes acting at La Fossa cone (Vulcano Island, Italy). La Fossa cone is a stratovolcano made up of pyroclastic deposits and lavas covered by tuffs from the last eruption, dated 1888-90. Its flanks are affected by intense water erosion phenomena leading to the formation of denudation surfaces due to sheet erosion, rills, gullies and small canyons. As a consequence of very intense rainfalls, episodic debris flows occur along main gullies and canyons. Fumarolic activity plays an important role in the control of erosion processes, being both an obstacle for the growth of vegetation and a weathering factor. The GIS analysis and comparison of geo-referenced maps and aerial photos highlighted the influence of man-made structures on erosion processes, with particular reference to deep modifications in the natural stream network induced by buildings and roads. The combined effects of volcanic and anthropogenic activities, together with the additional role played by the strong inter-annual variability of rainfall amounts and intensities, give rise to significant changes in water erosion rates. A total volume of 5,700 m3 of volcanic products eroded between the years 1980 and 2008 from the upper portion of La Fossa cone has been estimated by GIS analysis.

This paper reports the results of 1428 beta-thalassemia chromosomes studied in Sicily during a hemoglobinopathy control program starting in 1983. Molecular screening was performed by direct restriction enzyme analysis, allele specific oligonucleotide (ASO) hybridization, reverse dot blot analysis (RDB) and, for the rare or new mutations, by direct sequencing of polymerase chain reaction (PCR) products. Using these approaches 1410 (98.7%) out of 1428 beta-globin gene defects were characterized, involving 22 different beta-thalassemia mutations. Three of these were present at high frequency (beta(0)39, IVS1, 110 and IVS1,6); the other beta-globin gene defects were found at lower frequency. In the latter, we found a smaller group of mutations at a frequency lower than 10% (IVS1, 1, IVS2, 745, beta S) and a larger one at a frequency lower than 2% [-87, IVS1,2, IVS2,1, fr 6, fr 8 (-AA), fr 44, fr 76, -101, IVS1, 116, IVS1, 3'end G-C, IVS1,5 G-A, IVS1,5 G-C, cod 30, Lepore, delta beta, beta C]. The possible origin of this very large number of mutations is discussed, taking into account the historical point of view. Moreover, this approach has made a first trimester prenatal diagnosis program possible in our region in practically all cases, with a great improvement in general thalassemia management.