156 research outputs found
The BPS limit of rotating AdS black hole thermodynamics
We consider rotating, electrically charged, supersymmetric AdS black holes in
four, five, six and seven dimensions, and provide a derivation of the
respective extremization principles stating that the Bekenstein-Hawking entropy
is the Legendre transform of a homogeneous function of chemical potentials,
subject to a complex constraint. Extending a recently proposed BPS limit, we
start from finite temperature and reach extremality following a supersymmetric
trajectory in the space of complexified solutions. We show that the entropy
function is the supergravity on-shell action in this limit. Chemical potentials
satisfying the extremization equations also emerge from the complexified
solution.Comment: 51 pages; v3: new appendix on Legendre transform of the general
entropy function (6.1), matches published versio
The new “Vegetation map of Sicily (Italy)”: a synthetic overview of the distribution of European habitats on the territory.
The new "Vegetation map of Sicily (Italy)", recently published (Gianguzzi, Papini &
Cusimano, 2015), shows also a synthetic overview of the distribution of European habitats
in the territory; the study area has been extended to small islands circum-Sicilian
(archipelago of the Aeolian; Aegadian, Pelagie Ustica and Pantelleria islands), for a total
area of 25,703 km2.
Our work allowed to resume the knowledge status of the phytosociological studies on
vegetation carried out and to identify the actual plant landscape of the region; the map
was compiled in a Geographical Information Systems (GIS) environment, in order to
produce a cartographic representation in 1:10,000 scale (reduced to a 1:250,000 scale).
At the reference scale 36 phytocoenotic types are represented, 16 of which related to
European habitats of zonal vegetation (Mediterranean maquis, Quercus ilex woods,
Quercus suber woods, Castanea sativa woods, Quercus pubescens deciduous woods,
mesophilous deciduous woods, Fagus sylvatica woods, Betula aetnensis woods, woods
dominated by woody gymnosperms, forest edge shrubs, orophilous pulvinate shrubs,
shrublands and garrigues on substrates of carbonate nature and on substrates of siliceous
nature, Ampelodesmos mauritanicus grasslands, mesophilous and sub-hygrophilous
grasslands and pastures), 11 related to azonal vegetation (riparian vegetation,
psammophilous herbaceous vegetation, chasmo-halophitic vegetation, etc.) and 9
related to anthropogenic vegetation (arable lands and extensive herbaceous crops,
vineyards, olive groves and dry cultivation mosaics, hazelnut groves, irrigated citrus groves
and orchards, greenhouses, built-up areas).
Gianguzzi L., Papini F., Cusimano D., 2015 – Phytosociological survey vegetation map of
Sicily (Mediterranean region). – Journal of Maps:1-7
(http://dx.doi.org/10.1080/17445647.2015.1094969)
Phytosociological survey vegetation map of Sicily (Mediterranean region)
We present the results of a study aimed at developing a vegetation map of Sicily (Italy) including the smaller circum-Sicilian islands, for an area of approximately 25,703 km2. The work is a synthesis of studies carried out in accordance with the survey methodology of phytosociology in the last 40 years over the whole study area. The vegetation map of Sicily was compiled in a Geographical Information Systems (GIS) environment, in order to produce a cartographic representation at a scale of 1:10,000 (reduced to a scale of 1:250,000). The physiognomic-structural characteristics of the plant landscape of Sicily are analyzed, providing a general and, at the same time, detailed overview of the phytocoenotic aspects represented on the territory, as well as of the relative bibliographic references. At the reference scale, 36 types are represented, 16 of which are related to zonal vegetation (Mediterranean maquis, Quercus ilex woods, Quercus suber woods, Castanea sativa woods, Quercus pubescens deciduous woods, mesophilous deciduous woods, Fagus sylvatica woods, Betula aetnensis woods, woods dominated by woody gymnosperms, forest edge shrubs, orophilous pulvinate shrubs, shrublands and garrigues, Ampelodesmos mauritanicus grasslands, mesophilous and sub-hygrophilous grasslands and pastures), 11 are related to azonal vegetation (riparian, psammophilous herbaceous, chasmo-halophitic, etc.) and 9 are related to anthropogenic vegetation (arable lands and extensive herbaceous crops, vineyards, olive groves and dry cultivation mosaics, hazelnut groves, irrigated citrus groves and orchards, greenhouses, built-up areas)
Experimental Characterization of a Passive Emergency Heat Removal System for a GenIII + Reactor
Among the several types of passive safety systems adopted in new generation reactor designs, the experimental investigation of a closed loop, two-phase flow, natural circulation system is depicted. Emergency Heat Removal Systems (EHRSs) based on this solution are envisaged as safety-engineered features for advanced nuclear reactors, as in the IRIS reactor. An experimental facility simulating one EHRS-like loop has been built and operated at SIET labs in Piacenza (Italy). The facility is a natural circulation, sliding pressure, and electrically heated loop, with a helical coil steam generator as a heat source and a horizontal tube pool condenser as a heat sink. A steady-state analysis is provided to characterize the system behaviour and its key parameters. Because of the loop limited volume, oscillations of the main parameters (temperatures, flowrate, pressure) may be expected. The oscillating phenomena detected during the experimental campaign are discussed; a reasonable explanation is at last proposed
Experimental analysis of seasonal processes in shallow landslide in a snowy region through downscaled and in situ observation
The frequency and intensity of heavy precipitation events increased since the mid-20th century and, considering the climate crisis, it is important also to analyze the effects of processes and events that lead to faster snow mantle melting cycles in mountain areas.
Shallow landslides are induced by extreme hydrological events such as the occurrence of short and intense rainfall or by events of medium intensity but prolonged over time. Such slips involve generally reduced portions of land both in area and in thickness, however, they are dangerous due to the absence of warning signals and the lack of knowledge regarding their possible evolution.
This work deals with the experimental study of these landslides through the laboratory simulations on a small-scale slope, reproduced at the LIMAG Lab - Laboratory of mountain hydraulics and applied geology of the Lecco Campus and in situ seasonal processes observation at a mountain closed basin nearby Champoluc village in Aosta Valley region.
The central objective is to study the evolution of shallow landslides in reduced scale caused by external factor as snowmelt and rainfall and to compare the observations done in laboratory with the ones in situ. In order to investigate the behaviour of shallow landslides in these critical conditions, a series of sensors have been installed on the simulator. This technology includes three modified pressure transmitters for the pore water pressure evaluation which have been accompanied by other support instrumentation consisting of GoPro’s cameras, TDR (Time Domain Reflectometry) and georesistivimeter; all of them provide a cross check of phenomena processes.
Throughout the downscaled simulations with snow cover it was possible to observe several processes. The direct interaction between snow and ground does not favor the infiltration of a large amount of water. The protective role of snow lies in keeping the first film of soil at 0 degrees and loading the soil by decreasing its infiltrative capacity; this no longer occurs when the water melted by the snow flows downstream and begins to infiltrate into uncovered and warmer soils.
Without thermal or overload barriers, the water pours into the ground. Therefore, a potential susceptible area can be the subject of different filtering and infiltrative contributions from upstream, saturating quickly and collapsing.
These laboratory experiments are the starting point for the in-situ analyses and provide a comparison with the observations made by means of ad hoc instrumentation set up at the Champoluc station. Highly detailed information is obtained concerning the density and thickness of the snowpack during seasonal processes. These contribute to defining the hydrogeological processes within the terrain, already studied in the laboratory, and to establishing the water balance
Design, synthesis, conformational analysis, and biological activity of Cα1-to-Cα6 1,4- and 4,1-disubstituted 1H-[1,2,3]triazol-1-yl-bridged oxytocin analogues
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