187 research outputs found
Planetary stations and Abyssal Benthic Laboratories: An overview of parallel approaches for long-term investigation in extreme environments
In spite of the apparent great differences between deep ocean and space environment, significant similarities can be recognized when considering the possible solutions and technologies enabling the development of remote automatic stations supporting the execution of scientific activities. In this sense it is believed that mutual benefits shall be derived from the exchange of experiences and results between people and organizations involved in research and engineering activities for hostile environments, such as space, deep sea, and polar areas. A significant example of possible technology transfer and common systematic approach is given, which describes in some detail how the solutions and the enabling technologies identified for an Abyssal Benthic Laboratory can be applied for the case of a lunar or planetary station
The exploration of eastern Mediterranean deep hypersaline anoxic basins with MODUS: a significant example of technology spin-off from the Geostar Program
A significant example of technological spin-off from the GEOSTAR project is represented by the special-purpose instrumented module, based on the deep-sea ROV MODUS, which was developed in the framework of the EU-sponsored project BIODEEP. The goal to be achieved has been defined as the exploration, through real-time video images, measurements and accurate video-guided sampling, of the deep hypersaline anoxic basins of the eastern Mediterranean Sea at water depths well exceeding 3000 meters. Due to their peculiar characteristics, these basins are one of the most extreme environments on Earth and represent a site of utmost interest for their geochemical and microbial resources. The paper presents the strategies and the main results achieved during the two
cruises carried out within the BIODEEP project
Aggiornamento tecnologico e test funzionali del gravimetro da fondo LaCoste&Romberg modello U-HG24
Nel presente lavoro viene descritto l’aggiornamento tecnologico, effettuato in collaborazione con la società Tecnomare SpA, di un gravimetro da fondo LaCoste & Romberg modello U, serie H (numero HG24), di proprietà dell'Istituto Nazionale di Geofisica e Vulcanologia. Sono inoltre descritti e brevemente discussi i primi test in laboratorio ed i risultati di misure gravimetriche di fondo mare effettuate dal 19 al 22 Luglio 2010 nell'Area Marina Protetta del Parco Nazionale delle Cinque Terre. L'acquisizione di dati gravimetrici rientrava nelle attività specifiche del progetto di ricerca InSAS promosso e finanziato da eni Spa. La campagna a mare InSAS si è svolta in collaborazione con il NURC (NATO Undersea Research Centre) utilizzando come vettore marino il Coastal Research Vessel (CRV) ‘Leonardo’. Contestualmente all'attività di misure di gravità di fondo, sono stati acquisiti ed elaborati dal Politecnico di Milano diversi set di dati interferometrici Synthetic Aperture Sonar (SAS) su alcuni riflettori attivi e passivi localizzati nell'area di indagine.
La campagna di misure a mare è stata preceduta da una serie di test in laboratorio al fine di valutare la piena funzionalità dello strumento in esame. In questa fase sono state acquisite diverse serie temporali allo scopo di valutare la qualità della misura e la sua ripetibilità
Realization of a Knill-Laflamme-Milburn C-NOT gate -a photonic quantum circuit combining effective optical nonlinearities
Quantum information science addresses how uniquely quantum mechanical
phenomena such as superposition and entanglement can enhance communication,
information processing and precision measurement. Photons are appealing for
their low noise, light-speed transmission and ease of manipulation using
conventional optical components. However, the lack of highly efficient optical
Kerr nonlinearities at single photon level was a major obstacle. In a
breakthrough, Knill, Laflamme and Milburn (KLM) showed that such an efficient
nonlinearity can be achieved using only linear optical elements, auxiliary
photons, and measurement. They proposed a heralded controlled-NOT (CNOT) gate
for scalable quantum computation using a photonic quantum circuit to combine
two such nonlinear elements. Here we experimentally demonstrate a KLM CNOT
gate. We developed a stable architecture to realize the required four-photon
network of nested multiple interferometers based on a displaced-Sagnac
interferometer and several partially polarizing beamsplitters. This result
confirms the first step in the KLM `recipe' for all-optical quantum
computation, and should be useful for on-demand entanglement generation and
purification. Optical quantum circuits combining giant optical nonlinearities
may find wide applications across telecommunications and sensing.Comment: 6pages, 3figure
An innovative tsunami detector operating in tsunami generation environment
On August 25th 2007 a tsunami detector installed onboard the multi-parameter observatory GEOSTAR was successfully deployed at 3200 b. s. l. in the Gulf of Cadiz, Portugal. This activity is within the NEAREST EC Project (http://nearest.bo.ismar.cnr.it/ ). Among other deliverables, the NEAREST project will produce and test the basic parts of an operational prototype of a near field tsunami warning system. This system includes an onshore warning centre, based on the geophysical monitoring networks which are already operating, and a tsunami detector deployed on board GEOSTAR at the sea bottom. On land the warning centre is in charge of collecting, integrating, and evaluating data recorded at sea. At the sea bottom data is recorded and processed by an advanced type of tsunami detector which includes: a pressure sensor, a seismometer and two accelerometers. The detector communicates acoustically with a surface buoy in two-way mode. The buoy is equipped with meteo station, GPS and tiltmeter and is connected to a shore station via satellite link. The prototype is designed to operate in tsunami generation areas for detection-warning purpose as well as for scientific measurements. The tsunami detector sends a near real time automatic alert message when a seismic or pressure threshold are exceeded. Pressure signals are processed by the tsunami detection algorithm and the water pressure perturbation caused by the seafloor motion is taken into account. The algorithm is designed to detect small tsunami waves, less than one centimetre, in a very noisy environment. Our objective is to combine a novel approach to the tsunami warning problem, with a study of the coupling between the water column perturbations and sea floor motion, together with the long term monitoring of geophysical, geochemical and oceanographic parameters
The exploration of Eastern Mediterranean deep hypersaline anoxic basins with MODUS: a significant example of technology spin-off from the GEOSTAR program
A significant example of technological spin-off from the GEOSTAR project is represented by the special-purpose instrumented module, based on the deep-sea ROV MODUS, which was developed in the framework of the EU-sponsored project BIODEEP. The goal to be achieved has been defined as the exploration, through real-time video images, measurements and accurate video-guided sampling, of the deep hypersaline anoxic basins of the eastern Mediterranean Sea at water depths well exceeding 3000 meters. Due to their peculiar characteristics, these basins are one of the most extreme environments on Earth and represent a site of utmost interest for their geochemical and microbial resources. The paper presents the strategies and the main results achieved during the two cruises carried out within the BIODEEP project
Monitoring of a methane-seeping pockmark by cabled benthic observatory (Patras Gulf, Greece)
A new seafloor observatory, the gas monitoring
module (GMM), has been developed for continuous and
long-term measurements of methane and hydrogen sulphide
concentrations in seawater, integrated with temperature (T),
pressure (P) and conductivity data at the seafloor. GMM
was deployed in April 2004 within an active gas-bearing
pockmark in the Gulf of Patras (Greece), at a water depth of
42 m. Through a submarine cable linked to an onshore
station, it was possible to remotely check, via direct phone
connection, GMM functioning and to receive data in nearreal
time. Recordings were carried out in two consecutive
campaigns over the periods April–July 2004, and September
2004–January 2005, amounting to a combined dataset
of ca. 6.5 months. This represents the first long-term
monitoring ever done on gas leakage from pockmarks by
means of CH4+H2S+T+P sensors. The results show
frequent T and P drops associated with gas peaks, more
than 60 events in 6.5 months, likely due to intermittent,
pulsation-like seepage. Decreases in temperature in the
order of 0.1–1°C (up to 1.7°C) below an ambient T of ca.
17°C (annual average) were associated with short-lived
pulses (10–60 min) of increased CH4+H2S concentrations.
This seepage “pulsation” can either be an active process
driven by pressure build-up in the pockmark sediments, or a
passive fluid release due to hydrostatic pressure drops
induced by bottom currents cascading into the pockmark
depression. Redundancy and comparison of data from
different sensors were fundamental to interpret subtle proxy
signals of temperature and pressure which would not be
understood using only one sensor.Published297-302JCR Journalreserve
NEMO-SN1 (Western Ionian Sea, off Eastern Sicily): A Cabled Abyssal Observatory with Tsunami Early Warning Capability
The NEMO-SN1 (NEutrino Mediterranean Observatory - Submarine
Network 1) seafloor observatory is located in the central
Mediterranean, Western Ionian Sea, off Eastern Sicily Island (Southern
Italy) at 2100 m water depth, 25 km from the harbour of the city of
Catania. It is a prototype of cabled deep-sea multiparameter
observatory, and the first operating with real-time data transmission in
Europe since 2005. NEMO-SN1 is also the first-established node of
EMSO (European Multidisciplinary Seafloor Observatory,
http://emso-eu.org), one of the European large-scale research
infrastructures. EMSO will address long-term monitoring of
environmental processes related to marine ecosystems, climate change
and geo-hazards. NEMO-SN1 will perform geophysical and
environmental long-term monitoring by acquiring seismological,
geomagnetic, gravimetric, accelerometric, physico-oceanographic,
hydro-acoustic, bio-acoustic measurements to study earthquake and
tsunami generation, and to characterize ambient noise which includes
marine mammal sounds, and environmental and anthropogenic sources.
NEMO-SN1 is also equipped with a prototype tsunami detector, based
on the simultaneous measurement of the seismic and bottom pressure
signals and a new high performance tsunami detection algorithm.
NEMO-SN1 will be a permanent tsunami early warning node in
Western Ionian Sea, an area where very destructive earthquakes have
occurred in the past, some of them tsunamigenic (e.g., 1693, M=7.5;
1908, M=7.4).
Another important feature of NEMO-SN1 is the installation of a low
frequency-high sensibility hydrophone and two (scalar and vector,
respectively) magnetometers. The objective is to improve the tsunami
detection capability of SN1 through the recognition of tsunami-induced
hydro-acoustic and electro-magnetic precursors.SubmittedRhodes, Greece3A. Ambiente Marinorestricte
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
GEMS (Gamma Energy Marine Spectrometer) is a prototype of an autonomous radioactivity sensor for underwater measurements, developed in the framework for a development of a submarine telescope for neutrino detection (KM3NeT Design Study Project). The spectrometer is highly sensitive to gamma rays produced by 40K decays but it can detect other natural (e.g., 238U,232Th) and anthropogenic radio-nuclides (e.g., 137Cs). GEMS was firstly tested and calibrated in the laboratory using known sources and it was successfully deployed for a long-term (6 months) monitoring at a depth of 3200 m in the Ionian Sea (Capo Passero, offshore Eastern Sicily). The instrument recorded data for the whole deployment period within the expected specifications. This monitoring provided, for the first time, a continuous time-series of radioactivity in deep-sea.In press4.5. Studi sul degassamento naturale e sui gas petroliferiJCR Journalope
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