57 research outputs found

    Il primo OBS/H italiano per il monitoraggio e lo studio di faglie e vulcani sottomarini

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    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

    Il primo OBS/H italiano per il monitoraggio e lo studio di faglie e vulcani sottomarini

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    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

    New clones and old varieties: Quality of sicilian hillside apple cultivation

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    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

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    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

    Aloe-based edible coating to maintain quality of fresh-cut italian pears (Pyrus communis L.) during cold storage

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    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 ‘Coscia’ 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 dell’INGV

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    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

    System Level Analysis of Millimetre-wave GaN-based MIMO Radar for Detection of Micro Unmanned Aerial Vehicles

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    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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