1,055 research outputs found
Evaluation of the quality and antioxidant capacity of woodland strawberry biotypes in Sicily
In Sicily, the woodland strawberry grows wild in forest glades in the Madonie and Nebrodi mountains and on Mount Etna. In this region, the main
cultivated clone is Fragolina di Ribera, named after the towns where the crop originally developed. The cultivated woodland strawberry is different
from its wild counterparts not only in vegetative vigour and size, but also in organoleptic quality. Fragolina di Ribera has always been described with
sensory analysis as one of the best Sicilian berry. This study was carried out in Sicily and compared two June-bearing Fragaria vesca: Fragolina di
Ribera and Fragolina di Maletto, and an everbearing variety Regina delle Valli, in order to determine the production, quality and nutraceutical
characteristics of the fruit. Research results provided useful, more detailed information on those fruit compounds with nutritional and health benefits
and the June-bearing Fragolina di Ribera was found not only to produce highly sweet, bright red fruits, but also fruits with high antioxidant capacity
and high ascorbic acid, polyphenol and anthocyanin levels
Il primo OBS/H italiano per il monitoraggio e lo studio di faglie e vulcani sottomarini
L’Istituto Nazionale di Geofisica e Vulcanologia (INGV) ha testato con successo, nel luglio 2006, il
primo Ocean Bottom Seismometer with Hydrophone (OBS/H) italiano (Fig. 1). Lo strumento,
interamente progettato e realizzato all’Osservatorio di Gibilmanna del Centro Nazionale Terremoti,
dopo aver superato i test in laboratorio, in camera iperbarica a 600 bar ed in mare a 3412 m di
profondità , è stato deposto per 9 giorni (12-21/07/’06) sulla spianata sommitale del vulcano
sottomarino Marsili a 790 m di profonditĂ (Fig. 2) ed ha registrato 835 eventi tra cui un telesisma, 8
eventi regionali e circa 800 eventi vulcanici
Il primo OBS/H italiano per il monitoraggio e lo studio di faglie e vulcani sottomarini
L’Istituto Nazionale di Geofisica e Vulcanologia (INGV) ha testato con successo, nel luglio 2006, il primo Ocean Bottom Seismometer with Hydrophone (OBS/H) italiano (Fig. 1). Lo strumento, interamente progettato e realizzato all’Osservatorio di Gibilmanna del Centro Nazionale Terremoti, dopo aver superato i test in laboratorio, in camera iperbarica a 600 bar ed in mare a 3412 m di profondità , è stato deposto per 9 giorni (12-21/07/’06) sulla spianata sommitale del vulcano sottomarino Marsili a 790 m di profondità (Fig. 2) ed ha registrato 835 eventi tra cui un telesisma, 8 eventi regionali e circa 800 eventi vulcanici.La realizzazione dell’OBS/H si colloca nell’ambito dei progetti finanziati dalla convenzione tra l’INGV e il Dipartimento Nazionale della Protezione Civile (DPC), che ha avuto come obiettivo la costituzione di un primo pool strumentale, costituito da 7 OBS/H, da impiegare come rete mobile sottomarina in occasione di forti eventi sismici che dovessero interessare le coste e i mari italiani.
Tale progetto si inquadra in uno scenario di ben più ampio respiro che vedrà nei prossimi anni l’estensione a mare della rete sismica nazionale, obiettivo strategico inserito nel piano triennale dell’INGV che porterà entro il 2008 alla realizzazione della prima stazione italiana real-time collegata a terra via radio, che verrà posizionata a circa 30 miglia a sud-est di Ustica, luogo in cui è stato localizzato il terremoto di Palermo del 6 settembre 2002.
Il prototipo di OBS/H utilizzato nel test sul Marsili è stato equipaggiato con un sensore sismico Trillium 40s della Nanometrics ed un idrofono OAS E-2PD con banda di risposta piatta tra 0 e 5 kHz. I segnali emessi da questi strumenti sono stati registrati da un digitalizzatore a 21 bit a basso consumo (Geolon MLS della SEND) che ha acquisito i dati ad una frequenza di campionamento di 200 campioni al secondo, per sfruttare il più possibile l’ampia banda di risposta dell’idrofono, al fine di mettere in evidenza l’attività idrotermale del vulcano.
Il sensore sismico è posto all’interno di una bentosfera di 17 pollici (sfera di vetro certificata per operazioni sino a 6000 m di profondità ), installato su una base autolivellante controllata elettronicamente. Il digitalizzatore e le batterie sono poste all’interno di un contenitore in ERGAL 7075. Per il recupero dello strumento a fine esperimento, è stato utilizzato uno sganciatore acustico IXSEA AR816S-MR opportunamente modificato dal personale dell’osservatorio di Gibilmanna per attivare, una volta ricevuto il segnale di “release”, un sistema di sgancio elettrolitico (burn-wire).
Per deposizioni di lungo periodo, sino ad uno o due anni in relazione al tipo di sismometro a bordo, l’OBS/H sarà dotato della strumentazione indicata nella Tab. 1
Attualmente è in fase di progettazione un’evoluzione dello strumento che mira a dotarlo di un digitalizzatore a 24 bit, di un sistema di comunicazione basato su modem acustico e di un PC industriale con processore ARM grazie al quale, nell’eventualità di interventi della rete mobile sottomarina, sarà possibile estrarre tracce degli eventi verificatisi per una più accurata localizzazione dell’epicentro senza che si renda necessario il recupero dello strumento. Inoltre, mediante l’implementazione di algoritmi di trigger, sarà possibile l’utilizzo dell’OBS/H all’interno di un sistema di allerta tsunami in comunicazione con una boa di superficie collegata al centro di controllo via satellite
Observing Brownian motion in vibration-fluidized granular matter
At the beginning of last century, Gerlach and Lehrer observed the rotational
Brownian motion of a very fine wire immersed in an equilibrium environment, a
gas. This simple experiment eventually permitted the full development of one of
the most important ideas of equilibrium statistical mechanics: the very
complicated many-particle problem of a large number of molecules colliding with
the wire, can be represented by two macroscopic parameters only, namely
viscosity and the temperature. Can this idea, mathematically developed in the
so-called Langevin model and the fluctuation-dissipation theorem be used to
describe systems that are far from equilibrium? Here we address the question
and reproduce the Gerlach and Lehrer experiment in an archetype non-equilibrium
system, by immersing a sensitive torsion oscillator in a granular system of
millimetre-size grains, fluidized by strong external vibrations. The
vibro-fluidized granular medium is a driven environment, with continuous
injection and dissipation of energy, and the immersed oscillator can be seen as
analogous to an elastically bound Brownian particle. We show, by measuring the
noise and the susceptibility, that the experiment can be treated, in first
approximation, with the same formalism as in the equilibrium case, giving
experimental access to a ''granular viscosity'' and an ''effective
temperature'', however anisotropic and inhomogeneous, and yielding the
surprising result that the vibro-fluidized granular matter behaves as a
''thermal'' bath satisfying a fluctuation-dissipation relation
First long time OBS campaign in the Ionian Sea
The INGV started its interest to extend the seismic monitoring network to the sea in 1995 with
GEOSTAR (Geophysical and Oceanographic Station for Abyssal Research) project, coming out with the
realization of the first multidisclipinary observatory for deep-sea monitoring [Favali et al. 2002].
At the end of 2004, the National Earthquake Center (CNT) of INGV decided to provide a pool of
Ocean Bottom Seismometers to be employed as a submarine mobile network and to study submarine faults
and volcanoes. This was possible thanks to an agreement between the INGV and the Italian National Civil
Protection Department (DPC). On July 2006, the Gibilmanna OBS Lab, tested the first OBS prototype for
nine days on the flat top of the Marsili submarine volcano [D’Anna et al. 2007] and in early 2007 other seven
OBS’s were ready to be deployed on the seafloor.
In May 2007, within the European project NERIES (activity NA6), the Gibilmanna OBS Lab of the
INGV has deployed three Broad Band Ocean Bottom Seismometers (BBOBS) in the southern Ionian Sea at
3500-4000 meters of depth.
This area has been chosen during the NERIES – “NA6-BBOBS net” meeting in Rome, on the 11th of
September 2006 because at first, there are at the moment few seismological data [Scrocca et al., 2003] to
construct a reliable model for the Ionian lithosphere and also the rate and features of the seismicity in the
area between the Hyblean-Malta fault system and the accretionary prism of the Calabrian Arc are largely
unknown [Catalano et al. 2002].
The Ionian Sea is indeed one of the most seismically active area in the Mediterranean region with
several destructive earthquakes sometimes followed by tsunamis [Tinti et al. 2004]. The seismicity occurring
in the Ionian basin is characterized by large location uncertainties due to the lack of seafloor seismic stations.
In 2002, the quality of the seismic sensing and the location of earthquakes have been improved by the
deployment of the real-time submarine observatory SN-1, about 25 km offshore Eastern Sicily [Sgroi et al,
2007]. However, the SN-1 location only allows to characterize the seismicity in the area offshore the eastern
Sicily.
Two of the three OBS’s were successfully recovered on the 2nd of February 2008; the last one was
recovered on the 15th of March 2008 and another OBS was deployed on the same location to accomplish the
continuous long-term seismic monitoring task (until May 2010) as planned in NERIES project
What is the temperature of a granular medium?
In this paper we discuss whether thermodynamical concepts and in particular
the notion of temperature could be relevant for the dynamics of granular
systems. We briefly review how a temperature-like quantity can be defined and
measured in granular media in very different regimes, namely the glassy-like,
the liquid-like and the granular gas. The common denominator will be given by
the Fluctuation-Dissipation Theorem, whose validity is explored by means of
both numerical and experimental techniques. It turns out that, although a
definition of a temperature is possible in all cases, its interpretation is far
from being obvious. We discuss the possible perspectives both from the
theoretical and, more importantly, from the experimental point of view
Il nuovo OBS/H dell’INGV
In 2005, thanks to the 3-year agreement between Dipartimento Nazionale della Protezione Civile (DPC) and Istituto
Nazionale di Geofisica e Vulcanologia (INGV) - Centro Nazionale Terremoti (CNT), the project of the first Italian “Ocean
Bottom Seismometer with Hydrophone” (OBS/H) for long-term deployment was developed at the OBS Lab of the
Gibilmanna Observatory (Sicily).
The drawing of the instrument started in January 2005 and, after 18 months, the prototype was ready for test in laboratory,
in shallow and deep water.
Afterwards, the first OBS/H was tested during an oceanographic campaign on the Marsili submarine volcano, from the 10th
to the 21st of July 2006.More than 1000 events of several kinds were recorded: 817 VTB (Volcano Tectonic events, B-type), 159
HF (High Frequency events), 53 SDE (Short Duration Event), 8 regional events localized by INGV land network, 10 not
localized events, 1 teleseismic event an 2 rockfall events.
The INGV OBS/H are equipped with:
- Nanometrics Trillium 120p seismometers (theoretical flat response between 120s and 175 Hz) installed in a 17 inches
glass sphere on a Nautilus gimbal for the leveling or Guralp CMG40T-OBS (flat response between 60s and 100 Hz);
- Cox-Webb Differential Pressure Gauge (bandwidth 500s-2Hz) or OAS E-2PD hydrophone (0-5kHz);
- 21 bits, 4 channels SEND Geolon-MLS digitizer with sampling frequency up to 200 Hz
A multiscale method for gamma/h discrimination in extensive air showers
We present a new method for the identification of extensive air showers initiated by different primaries. The method uses the multiscale concept and is based on the analysis of multifractal behaviour and lacunarity of secondary particle distributions together with a properly designed and trained artificial neural network. The separation technique is
particularly suited for being applied when the topology of the particle distribution in the shower front is as largely detailed as possible. Here, our method is discussed and applied to a set of fully simulated vertical showers in the experimental framework of ARGO-YBJ, taking advantage of both the space and time distribution of the detected secondary particles in the shower front, to obtain hadron to gamma primary separation in EAS analysis. We show that the presented approach gives very good results, leading, in the 1-10 Tev energy range, to an improvement of the discrimination power with respect to the existing figures for extended shower detectors. The technique shows up to be very promising and its application may have important astrophysical prospects in different experimental environment of extended air shower study
Urban MEMS based seismic network for post-earthquakes rapid disaster assessment
In this paper, we introduce a project for the realization
of the first European real-time urban seismic network
based on Micro Electro-Mechanical Systems (MEMS) technology.
MEMS accelerometers are a highly enabling technology,
and nowadays, the sensitivity and the dynamic range
of these sensors are such as to allow the recording of earthquakes
of moderate magnitude even at a distance of several
tens of kilometers. Moreover, thanks to their low cost and
smaller size, MEMS accelerometers can be easily installed in
urban areas in order to achieve an urban seismic network constituted
by high density of observation points. The network
is being implemented in the Acireale Municipality (Sicily,
Italy), an area among those with the highest hazard, vulnerability
and exposure to the earthquake of the Italian territory.
The main objective of the implemented urban network will
be to achieve an effective system for post-earthquake rapid
disaster assessment. The earthquake recorded, also that with
moderate magnitude will be used for the effective seismic
microzonation of the area covered by the network. The implemented
system will be also used to realize a site-specific
earthquakes early warning system
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