57 research outputs found
Il primo OBS/H italiano per il monitoraggio e lo studio di faglie e vulcani sottomarini
LâIstituto 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 allâOsservatorio 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 profonditĂ , è stato deposto per 9 giorni (12-21/07/â06) 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.La realizzazione dellâOBS/H si colloca nellâambito dei progetti finanziati dalla convenzione tra lâINGV 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 piĂš ampio respiro che vedrĂ nei prossimi anni lâestensione a mare della rete sismica nazionale, obiettivo strategico inserito nel piano triennale dellâINGV che porterĂ entro il 2008 alla realizzazione della prima stazione italiana real-time collegata a terra via radio, che verrĂ 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 piĂš possibile lâampia banda di risposta dellâidrofono, al fine di mettere in evidenza lâattivitĂ idrotermale del vulcano.
Il sensore sismico è posto allâinterno di una bentosfera di 17 pollici (sfera di vetro certificata per operazioni sino a 6000 m di profonditĂ ), installato su una base autolivellante controllata elettronicamente. Il digitalizzatore e le batterie sono poste allâinterno 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 dellâosservatorio di Gibilmanna per attivare, una volta ricevuto il segnale di âreleaseâ, 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, lâOBS/H sarĂ dotato della strumentazione indicata nella Tab. 1
Attualmente è in fase di progettazione unâevoluzione 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, nellâeventualitĂ di interventi della rete mobile sottomarina, sarĂ possibile estrarre tracce degli eventi verificatisi per una piĂš accurata localizzazione dellâepicentro senza che si renda necessario il recupero dello strumento. Inoltre, mediante lâimplementazione di algoritmi di trigger, sarĂ possibile lâutilizzo dellâOBS/H allâinterno di un sistema di allerta tsunami in comunicazione con una boa di superficie collegata al centro di controllo via satellite
Il primo OBS/H italiano per il monitoraggio e lo studio di faglie e vulcani sottomarini
LâIstituto 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 allâOsservatorio 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
profonditĂ , è stato deposto per 9 giorni (12-21/07/â06) 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
New clones and old varieties: Quality of sicilian hillside apple cultivation
Aims: The aim of this study is to evaluate the qualitative characteristics of the new clones according to the Mediterranean hillside growing environment and, at the same time, to highlight the qualitative peculiarities of the old varieties in order to avoid genetic loss. Introduction: Several apple varieties are constantly selected for improved quality traits and introduced for cultivation and marketing in addition to a few traditional and affirmed varieties. On the other side, local genotype and ancient varieties are still valorised due to the request of a niche market. Methods: We have studied the physico-chemical quality and the sensory traits of the fruit obtained in this particular environment. Results: Our study reveals a qualitative response to the environment in a genotype-dependent manner. As expected, the physico-chemical characteristics favour the new clones. Conclusion: Both old varieties and new clones of apple fruit, grown in the Mediterranean area, turned out to be of high quality. Nevertheless, results revealed the better characteristics of new clones for commercialization in large-scale supply chain
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 [DâAnna et al. 2007] and in early 2007 other seven
OBSâs 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 â âNA6-BBOBS netâ 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 OBSâs 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
Aloe-based edible coating to maintain quality of fresh-cut italian pears (Pyrus communis L.) during cold storage
Pear fruits are known for their antioxidant and nutritional characteristics. However, they are very susceptible to rapid decay. Edible coating (EC) represents a good strategy to maintain postharvest quality. The effects of two EC in slowing down the senescence processes in fresh-cut âCosciaâ pears were investigated: EC1 (A. vera gel, hydroxypropyl-methylcellulose and pomegranate seeds oil (PSO), EC2 (A. vera gel and hydroxypropyl-methylcellulose). Weight loss, firmness and colour decrease more slowly in both EC-treated than in untreated (CTR) slices; soluble solid content increases faster in CTR, indicating a faster ripening process. The specific investigation of undesired microorganisms did not generate any colony in all analysed samples. Sensory analysis confirmed that the tasters preferred the EC2-treated samples, as they were the only ones that did not show undesirable flavours until the last day of storage
Il nuovo OBS/H dellâINGV
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 âOcean
Bottom Seismometer with Hydrophoneâ (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
System Level Analysis of Millimetre-wave GaN-based MIMO Radar for Detection of Micro Unmanned Aerial Vehicles
The detection of Unmanned Aerial Vehicles (UAVs) of micro/nano dimensions, is becoming a hot topic, due to their large diffusion, and represents a challenging task from both the system architecture and components point of view. The Frequency Modulated Continuous Wave (FMCW) radar architecture in a Multi-Input Multi-Output configuration has been identified as the most suitable solution for this purpose, due to both its inherent short-range detection capability and compact implementation. This paper describes the operation and technology challenges inherent to the development of a millimeter-wave FMCW MIMO radar for small UAVs detection. In particular it analyzes the sub-systems specifications and the expected system performance with respect to a chip set designed and developed in GaN at 37.5 GHz applications
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