139 research outputs found
An improved seismicity picture of the Southern Tyrrhenian area by the use of OBS and land-based networks: the TYDE experiment
The problem of large location uncertainties for seismicity occurring in the Southern Tyrrhenian
Sea have been partially exceeded during the implementation of the long-term scientific mission of
the TYrrhenian Deep sea Experiment (TYDE), which allowed the installation of 14 wide-band
Ocean Bottom Seismometers (OBS) and Hydrophones (OBH) in the period December 2000 â May
2001 on the sea-bottom floor around the Aeolian and Ustica Islands. Local events recorded at landstations
have been observed also on the seismograms of the Ocean Bottom Seismic Network
(OBSN). Moreover, some hundreds of low magnitude events, undetected from the land networks,
have been recorded.
We combined the readings of body wave arrival times from OBS-OBH with those from landstations
to localise seismic events. We focused our study on three clusters of events representative
of the seismic activity of the area: (i) âdeepâ events, (ii) Ustica (iii) NE-Sicily. The analysis of the
integrated data set of the seismicity off-shore and on-shore, obtained from the combined land-OBS
seismic network (Ustica sequence and Deep events), has improved locations in terms of RMS
residuals, azimuthal gap, epicentral and hypocentral errors. Moreover, further classes of events have
been analysed: the first one includes some local events that could be located only by integrating single trigger readings from the few available land-stations with the OBSN-data; the second one
comprises local events that have been detected only by the OBS-OBH stations. In particular, the last
cluster underlines the importance of an OBSN in the Tyrrhenian deep basin to reveal its unknown
intense micro-seismicity, permitting to better understand both the tectonic and geodynamic picture
of the area
La legitimaciĂłn en el CĂłdigo Civil y en la Ley 14.367 : [segunda parte]
Fil: Frugoni Rey, Guillermo F. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Civil I. Buenos Aires, Argentina"Por omisiĂłn en LECCIONES Y ENSAYOS N° 17 se publicaron sĂłlo los puntos I y II del presente artĂculo. En vista de ello, en este nĂșmero se reproducen. procediĂ©ndose a la publicaciĂłn Ăntegra del trabajo. (Nota del Consejo de RedacciĂłn)
La legitimaciĂłn en el CĂłdigo Civil y en la Ley 14.367 : [primera parte]
Fil: Frugoni Rey, Guillermo F. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Civil I. Buenos Aires, Argentin
Ammonium recovery from agro-industrial digestate using bioelectrochemical systems
Abstract
Growing food and biomass production at the global scale has determined a corresponding increase in the demand for and use of nutrients. In this study, the possibility of recovering nitrogen from agro-industrial digestate using bioelectrochemical systems was investigated: two microbial electrolysis cells (MECs) were fed with synthetic and real digestate (2.5 gNH4+-N Lâ1). Carbon felt and granular graphite were used as anodes in MEC-1 and MEC-2, respectively. As to synthetic wastewater, the optimal nitrogen load (NL) for MEC-1 and -2 was 1.25 and 0.75 gNH4+-N dâ1, respectively. MEC-1 showed better performance in terms of NH4+-N removal efficiency (39 ± 2.5%) and recovery rate (up to 70 gNH4+-N mâ2dâ1), compared to MEC-2 (33 ± 4.7% and up to 30 gN mâ2dâ1, respectively). At the optimal hydraulic retention time, lower NH4+-N removal efficiencies and recovery rates were observed when real digestate was fed to MEC-1 (29 ± 6.6% and 60 ± 13 gNH4+-N mâ2dâ1, respectively) and MEC-2 (21 ± 7.9% and 10 ± 3.6 gNH4+-N mâ2dâ1, respectively), likely due to the higher complexity of the influent. The average energy requirements were 3.6â3.7 kWh kgNremovedâ1, comparable with values previously reported in the literature and lower than conventional ammonia recovery processes. Results are promising and may reduce the need for costly and polluting processes for nitrogen synthesis
Foreland deformational pattern in the Southern Adriatic Sea
Two major deformation belts occur in the portion of the Adriatic Sea offshore the Gargano Promontory. Although
these two belts display similar characters on seismic profiles, they are different in other respects. The NE-SWtrending
Tremiti Deformation Belt, located north of the Gargano Promontory, originated during the Plio-Quaternary,
while the E-W-trending South Gargano Deformation Belt, located south of the Gargano Promontory,
formed in a time span that goes from Eocene to early Pliocene. On the ground of structural and stratigrafic
evidence these deformation belts are interpreted as originated by tectonic inversion of Mesozoic extensional
faults. This inversion tectonics, of Tertiary age, can be related to the evolution of the fold-and-thrust belts that
surround the Adriatic Sea.
A moderate seismic activity, recorded around the Tremiti Island, and historical seismological data suggest that
the whole of study area is, at present, seismically active. Therefore, this portion of the Adriatic block still
represents a preferental site of deformation
Foreland tectonics in the southern Adriatic Sea
Two major deformation belts occur in the portion of the
Adriatic Sea offshore the Gargano Promontory. The NE-SW
- trending Tremiti Deformation Belt, located north of the
Gargano Promontory, originated during the Plio-
Quaternary, while the E-W-trending South Gargano Deformation
Belt, located south of the Gargano Promontory,
formed in a time span from Eocene to Early Pliocene. These
deformation belts may have originated by tectonic inversion
of Mesozoic extensional faults. This inversion tectonics, of
Tertiary age, can be related to the evolution of the fold-and thrust
belts surrounding the Adriatic Sea.
The whole of the study area is, at present, seismically
active and represents a preferential site of deformation
Molecular Analysis of Relapses or Reinfections of Clostridium difficile-Associated Diarrhea
Recurrence is a major complication of Clostridium difficile associated diarrhoea and occurs in 15 to 20% of patients after discontinuation of therapy. Strains from 53 patients with Clostridium difficile recurrences were fingerprinted by PCR ribotyping. Reinfection with a different strain occurred in 15 of 53 patients (28,3 %), while 38 patients relapsed. These data suggest the need to perform molecular typing for implementation of infection control procedures and for a more appropriate therapeutic strategy
Underwater geophysical monitoring for European Multidisciplinary Seafloor and water column Observatories
We present a review of our work on data acquired by GEOSTAR-class (GEophysical and Oceanographic STation for Abyssal Research) observatories deployed at three EMSO (European Multidisciplinary Seafloor and water-column Observatory; http://www.emso-eu.org) sites in southern European waters where strong geo-hazards are present: the Western Iberian Margin, the Western Ionian Sea, the Marmara Sea, and the Marsili basin in the Tyrrhenian Sea. A procedure for multiparameter data quality control is described. Then we explain why the seafloor is an interesting observation point for geophysical parameters and how it differs from land sites. We consider four interesting geophysical phenomena found at the EMSO sites that are related to geo-hazard. In the first case, we show how unknown seismicity and landslides in the Western Ionian Sea were identified and roughly localised through a single-sensor analysis based on the seismometer. In the second case, we concentrate on the problem of near-coast tsunami generation and describe a Tsunami Early Warning Detection (TEWD) system, tested in the Western Iberian Margin and currently operating in real time at the Western Ionian site. In the third case, we consider two large volcanoes in the central Mediterranean area, Mt. Etna and the Marsili seamount. Signals from the seismometer and gravimeter recorded at the seafloor at 2100 m b.s.l. show various phases of Mt. Etna's 2002â2003 eruption. For the less-known Marsili we illustrate how several indicators coming from different sensors point to hydrothermal activity. A vector magnetometer at the two volcanic sites helps identify the magnetic lithospheric depth. In the fourth and final case, we present a multiparameter analysis which was focused on finding possible correlations between methane seepage and seismic energy release in the Gulf of Izmit (Marmara Sea).Published12â301A. Geomagnetismo e Paleomagnetismo6A. Monitoraggio ambientale, sicurezza e territorioJCR Journalrestricte
GEOSTAR, an observatory for deep sea geophysical and oceanographic researches: characteristics, first scientific mission and future activity
GEOSTAR (GEophysical and Oceanographic STation for Abyssal Research) is a project funded by in the 4th Framework Programme of the European Commission, with the aim of developing an innovative deep sea benthic observatory capable of carrying out long-term (up to 1 year) scientific observations at abyssal depths.
The configuration of the observatory, conceived to be a node of monitoring networks, is made up of two main subsystems: the Bottom Station, which in addition to the acquisition and power systems and all the sensors also hosts the communications systems; and the Mobile Docker, a dedicated tool for surface-assisted deployment and recovery. At present the Bottom Station is equipped with a triaxial broad-band seismometer, two magnetometers (fluxgate and scalar), CTD, transmissometer, ADCP, but it can easily host other sensors for different experiments.
The first phase of the project, started in November 1995, was concluded with the demonstration mission in Adriatic Sea at shallow water depth (42 m) in August - September 1998. Some preliminary results of this first scientific experiment are presented and discussed. The second phase, started in 1999, will end with a long-term deep sea scientific mission, scheduled during 2000 for 6-8 months at 3400 m.w.d. in the southern Tyrrhenian bathyal plain.Published491-4973A. Ambiente MarinoN/A or not JCRrestricte
Observing Volcanoes from the Seafloor in the Central Mediterranean Area
The three volcanoes that are the object of this paper show different types of activity that are representative of the large variety of volcanism present in the Central Mediterranean area. Etna and Stromboli are sub-aerial volcanoes, with significant part of their structure under the sea, while the Marsili Seamount is submerged, and its activity is still open to debate. The study of these volcanoes can benefit from multi-parametric observations from the seafloor. Each volcano was studied with a different kind of observation system. Stromboli seismic recordings are acquired by means of a single Ocean Bottom Seismometer (OBS). From these data, it was possible to identify two different magma chambers at different depths. At Marsili Seamount, gravimetric and seismic signals are recorded by a battery-powered multi-disciplinary observatory (GEOSTAR). Gravimetric variations and seismic Short Duration Events (SDE) confirm the presence of hydrothermal activity. At the Etna observation site, seismic signals, water pressure, magnetic field and acoustic echo intensity are acquired in real-time thanks to a cabled multi-disciplinary observatory (NEMO-SN1 ). This observatory is one of the operative nodes of the European Multidisciplinary Seafloor and water-column Observatory (EMSO; www.emso-eu.org) research infrastructure. Through a multidisciplinary approach, we speculate about deep Etna sources and follow some significant events, such as volcanic ash diffusion in the seawater
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