136 research outputs found
Characterization of extreme weather events on Italian roads
According to climate modellers, probability, frequency, duration, intensity (seriousness) of extreme weather events (extreme
temperatures and rainfall) are increasing and will be more frequent in future. The former will lead to higher surface runoff and flood events while the latter will cause landslides phenomena and a break of roads network. The impact of such events depends greatly on the physical hydraulic and mechanical properties of soils. Increasing numbers of extreme events in winter time in recent years have demonstrated the paramount importance of effective and integrated management of land resources in the protection of the environment
and of the road network. In Italy more than 10% of the territory has been classified as having a high or very high hydro-geological risk, affecting 80% of the Italian municipalities. The impacts on population and the economic damages are relevant. In Italy over the last 20
years, floods and landslides had an impact on more than 70 000 people and caused economic damage of at least 11 billion euro. Since 2000, the Italian Ministry for the Environment entrusted ISPRA the task of monitoring the programmes of emergency measures toreduce hydrogeological risk. (ReNDiS project, database of mitigation measures against floods and landslides)
Remote colorimetric measurements by hyperspectral lidar compared to contact conventional colorimetry
Lidars have many applications in different fields, including the field of Cultural Heritage. The purpose of this study is to evaluate a scanning hyperspectral lidar prototype developed at ENEA Center of Frascati as a useful tool for colorimetric analysis when samples cannot be studied with standard contact instruments. A certified X-Rite Color-checker sample, consisting of 24 colored blocks with a coordinated colorimetric certificate, was analyzed. In order to obtain colorimetric data from the reflectance spectra, the precepts of the Commission de l'Éclairage were followed and an algorithm was developed to calculate the color difference between the certified values of the Color-checker and commercial and non-commercial spectrophotometers and those obtained by the lidar, confirming this latter as a useful tool for remote colorimetry
Il rischio idrogeologico e la rete viaria nazionale minore
Il rischio definisce la possibilitĂ che un fenomeno naturale o antropico possa causare effetti dannosi sulla popolazione, sugli insediamenti, sulle infrastrutture o in generale su quelli che vengono definiti elementi esposti.
Il concetto di rischio è legato non solo alla capacità di calcolare la probabilità che un evento pericoloso accada, ma anche alla capacità di definire e quantificarne il danno provocato. Il territorio nazionale italiano, data la sua conformazione orografica, geologica e geomorfologica caratterizzata da un???orografia giovane e da rilievi in sollevamento, è sempre stato interessato da fenomeni idraulici e geologici (fenomeno impropriamente chiamato, anche se ormai di uso corrente, (dissesto idrogeologico) di notevole intensità . Il caso di studio adottato fa riferimento alla Provincia di Lucca, data la particolare rilevanza di
fenomeni di dissesto idrogeologico in questa area
IBIS/PICsIT in-flight performances
PICsIT (Pixellated Imaging CaeSium Iodide Telescope) is the high energy
detector of the IBIS telescope on-board the INTEGRAL satellite. PICsIT operates
in the gamma-ray energy range between 175 keV and 10 MeV, with a typical energy
resolution of 10% at 1 MeV, and an angular resolution of 12 arcmin within a
\~100 square degree field of view, with the possibility to locate intense point
sources in the MeV region at the few arcmin level. PICsIT is based upon a
modular array of 4096 independent CsI(Tl) pixels, ~0.70 cm^2 in cross-section
and 3 cm thick. In this work, the PICsIT on-board data handling and science
operative modes are described. This work presents the in-flight performances in
terms of background count spectra, sensitivity limit, and imaging capabilities.Comment: 8 pages, 4 figures. Accepted for publication on A&A, special issue on
First Science with INTEGRA
BeppoSAX detection of the Fe K line in the starburst galaxy NGC253
Preliminary results obtained from BeppoSAX observation of the starburst
galaxy NGC253 are presented. X-ray emission from the object is clearly extended
but most of the emission is concentrated on the optical nucleus. Preliminary
analysis of the LECS and MECS data obtained using the central 4' region
indicates that the continuum is well fitted by two thermal components at 0.9
keV and 7 keV. Fe K line at 6.7 keV is detected for the first time in this
galaxy; the line has an equivalent width of ~300eV. The line energy and the
shape of the 2-10 keV continuum strongly support thermal origin of the hard
X-ray emission of NGC253. From the measurement of the Fe K line the abundances
can be unambiguously constrained to ~0.25 the solar value. Other lines clearly
detected are Si, S and Fe XVIII/Ne, in agreement with ASCA results.Comment: 4 pages, LateX, 2 figures (included). Uses espcrc2.sty (included) To
appear in The Active X-ray Sky: Results from BeppoSAX and Rossi-XTE, Rome,
Italy, 21-24 October, 1997. Eds.: L. Scarsi, H. Bradt, P. Giommi and F. Fior
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