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Cazzuffi D.,Centro Elettrotecnico Sperimentale Italiano | Calvarano L.S.,University of Reggio Calabria | Cardile G.,University of Reggio Calabria | Moraci N.,University of Reggio Calabria | Recalcati P.,Tenax GTO
Geosynthetics | Year: 2011

The use of geosynthetics to improve the soil mechanical response has become increasingly common practice in geotechnical engineering applications. Geosynthetic materials are commonly used in soil reinforced structures, in embankment toe reinforcements on compressible ground, and in paved and unpaved roads. The test materials used in this study have been classified and mechanically characterized by standard laboratory tests allowed to evaluate the main strength and deformability parameters necessary to develop the next phase of pullout test analysis and discussions. It is possible to say that the pullout interaction mechanism is progressively developed along the reinforcement specimen length, in the latter behavior, while it is developed almost at the same time along the geogrid in the former one. In particular, the maximum percentage difference of peak pullout resistance equal to 19% is given with the comparison between the extruded geogrid GGEM2 and the woven geogrid GGK, while the greater percentage difference is equal to about 21% in the comparison between the extruded geogrid GGEM2 the welded geogrid GGW. Source

Poelman D.R.,Royal Meteorological Institute of Belgium | Schulz W.,OVE ALDIS | Diendorfer G.,OVE ALDIS | Bernardi M.,Centro Elettrotecnico Sperimentale Italiano
Natural Hazards and Earth System Sciences | Year: 2016

Cloud-to-ground (CG) lightning data from the European Cooperation for Lightning Detection (EUCLID) network over the period 2006-2014 are explored. Mean CG flash densities vary over the European continent, with the highest density of about 6 km-2 yr-1 found at the intersection of the borders between Austria, Italy and Slovenia. The majority of lightning activity takes place between May and September, accounting for 85% of the total observed CG activity. Furthermore, the thunderstorm season reaches its highest activity in July, while the diurnal cycle peaks around 15:00 UTC. A difference between CG flashes over land and sea becomes apparent when looking at the peak current estimates. It is found that flashes with higher peak currents occur in greater proportion over sea than over land. © Author(s) 2016. Source

Brenna M.,Polytechnic of Milan | De Berardinis E.,Centro Elettrotecnico Sperimentale Italiano | Delli Carpini L.,ENEL S.p.A | Foiadelli F.,Polytechnic of Milan | And 6 more authors.
IEEE Transactions on Smart Grid | Year: 2013

The widespread use of distributed generation (DG), which is installed in medium-voltage distribution networks, impacts the future development of modern electrical systems that must evolve towards smart grids. A fundamental topic for smart grids is automatic distributed voltage control (ADVC). The voltage is now regulated at the MV busbar acting on the on-load tap changer of the HV/MV transformer. This method does not guarantee the correct voltage value in the network nodes when the distributed generators deliver their power. In contrast, the ADVC allows control of the voltage acting on a single generator; therefore, a better voltage profile can be obtained. In this paper, an approach based on sensitivity theory is shown to control the node voltages regulating the reactive power injected by the generators. After the theoretical analysis, a numerical example is presented to validate the theory. The proposed voltage regulation method has been developed in collaboration with Enel Distribuzione S.p.A. (the major Italian DSO), and it will be applied in the Smart Grids POI-P3 pilot project, which is financed by the Italian Economic Development Ministry. Before the real field application in the pilot project, a real-time digital simulation has been used to validate the algorithm presented. Moving in this direction, Enel Distribuzione S.p.A. built a new test center in Milan equipped with a real-time digital simulator (from RTDS Technologies). © 2010-2012 IEEE. Source

Iulianelli A.,CNR Institute on Membrane Technology | Liguori S.,CNR Institute on Membrane Technology | Longo T.,CNR Institute on Membrane Technology | Tosti S.,ENEA | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2010

A catalytic Pd-Ag membrane reactor has been packed with a Co-Al2O3 catalyst to perform the ethanol steam reforming reaction using a simulated bio-ethanol mixture (H2O/C2H5OH feed molar ratio = 18.7/1). In Part I of this work, low hydrogen recovery (≤30%) and CO-free hydrogen yield (≤20%) were obtained. In this second study the influence of higher pressure and sweep-gas flow rate was studied in order to improve the membrane reactor performances in terms of higher ethanol conversion, CO-free hydrogen yield and hydrogen recovery. The counter-current sweep-gas flow configuration was used for studying the effect of the reaction pressure and the sweep factor on the reaction system, while the co-current flow configuration was also considered for analysing the weight hourly space velocity effect. Moreover, a comparison with a traditional reactor working at the same MR operating conditions was also realized. As best results, the membrane reactor showed 100% ethanol conversion, 95.0% CO-free hydrogen recovery and ∼60.0% CO-free hydrogen yield, operating at 400 °C and 3.0 (abs) bar. © 2009 Professor T. Nejat Veziroglu. Source

Solomos G.,European Commission - Joint Research Center Ispra | Berra M.,Centro Elettrotecnico Sperimentale Italiano
Materials and Structures/Materiaux et Constructions | Year: 2010

The dynamic behavior of the bond slip between a deformed reinforcing bar and plain concrete has been experimentally investigated by employing Hopkinson bar techniques. Pullout tests with various specimen types (unconfined, confined, cast-in-place, post-installed etc.) have been performed. Pullout of the steel rebar and splitting of the concrete cylinder have been the failure modes induced. Test results comprise peak pullout forces and complete bond stress-slip diagrams. They clearly show that the dynamic pullout forces and curves are well above the static ones, and that the pullout work of bond failure is considerably greater for the dynamic impact loading. Confinement, provided by a steel tube, leads to improved bonding; peak loads increase up to 2.5 times. The effects of bond length and concrete strength have also been put into evidence. Finally it has been verified that post-installed rebars, depending upon the particular adhesive employed, can achieve the same bond resistance as the cast-in-place ones. © 2009 RILEM. Source

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