807 research outputs found
The Role Played by Ionic Liquids in Carbohydrates Conversion into 5-Hydroxymethylfurfural: A Recent Overview
Obtaining industrially relevant products from abundant, cheap, renewable, and low-impacting sources such as lignocellulosic biomass, is a key step in reducing consumption of raw fossil materials and, consequently, the environmental footprint of such processes. In this regard, a molecule that is similar to 5-hydroxymethylfurfural (5-HMF) plays a pivotal role, since it can be produced from lignocellulosic biomass and gives synthetic access to a broad range of industrially important products and polymers. Recently, ionic liquids (ILs) have emerged as suitable solvents for the conversion of biomass and carbohydrates into 5-HMF. Herein, we provide a bird’s-eye view on recent achievements about the use of ILs for the obtainment of 5-HMF, covering works that were published over the last five years. In particular, we first examine reactions involving homogeneous catalysis as well as task-specific ionic liquids. Then, an overview of the literature addressing the use of heterogeneous catalysts, including enzymes, is presented. Whenever possible, the role of ILs and catalysts driving the formation of 5-HMF is discussed, also comparing with the same reactions that are performed in conventional solvents
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
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
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
Catalysis in Supramolecular Systems: the Case of Gel Phases
Supramolecular gels are a fascinating class of materials, originated by the self-assembly of low molecular weight molecules. Underpinned by non-covalent interactions, they find application in a diverse range of fields. Among these, supramolecular gels can be considered as organized, non-conventional reaction media, able to influence reactivity in a radically different way, compared with what happens in solution. This short review will focus on this aspect, covering literature from 2010 onwards, addressing the application of supramolecular gels as reaction media. In particular, in the first section we explore organocatalytic reactions in gel phase, with wide synthetic relevance, such as aldol and Mannich reactions as well as Friedel Crafts or ester hydrolysis processes. Subsequently, focus is laid on metal-catalysed reactions, among which relevance is given to widely used reactions like cross-coupling and click reactions. Then, the final sections describe the use of supramolecular gels as reaction media for photo- and biocatalysed processes
DBS-Based Eutectogels: Organized Vessels to Perform the Michael Addition Reaction**
Supramolecular eutectogels were obtained from the gelation of 1,3 : 2,4-dibenzylidene-D-sorbitol (DBS) in cholinium chloride-based deep eutectic solvents (DES), differing for the nature of the hydrogen bond donor. Ethylene glycol, diethylene glycol, triethylene glycol, glycerol and urea were tested. Soft materials were fully characterized, determining critical gelation concentration, gel-sol transition temperatures and mechanical properties. Furthermore, to have information about the organization of the gelator in the tridimensional network, resonance light scattering, circular dichroism and microscopy investigations were performed. Eutectogels were used as organized “vessels” to perform the L-proline catalyzed Michael addition reaction. The probe reaction was carried out in gel phase and in DES solution. Data collected shed light on the effect that gel microenvironment exerts on the outcome of the reaction. In general, gel phases allowed having comparable or even better results than the ones collected in DES solution, with better results obtained in soft materials with the highest organization, as accounted for by the presence of larger aggregates and the occurrence of stronger intermolecular interactions. In turn, this accounts also for the effect of substrates structure that indicates that better yields could be obtained in the presence of more flexible nucleophile and dienones, having more extended π-surface
INGV Broad Band Ocean Bottom Seismometers deployed in the Ionian Sea
In May 2007, within the monitoring activities carried out in cooperation with the Italian
National Civil Protection Department (DPC) and European NERIES project (activity
NA6), INGV has deployed three Broad Band Ocean Bottom Seismometers in
the southern Ionian Sea at 3500/4000 meters of depth. The OBS’s are equipped with
a Nanometrics Trillium 120p seismometer, a Cox-Webb Differential Pressure Gauge
and a 21 bits SEND Geolon-MLS digitizer. The three OBS’s, entirely developed at
the Gibilmanna Geophysical Observatory of the INGV National Earthquake Center
(CNT), are part of a pool of eight ready to deploy instruments and they are the first
Italian OBS’s taking part in a long term experiment: two of them will be recovered
by February 2008, whereas the third, in the deep Ionian Sea, will be replaced every
year, until May 2010, to accomplish the continuous long-term seismic monitoring
task of the EU NERIES project. The area selected for the deployment is a region
of high scientific interest for several reasons: i) there are no seismological data on
the structure of the Ionian lithosphere; ii) the level and features of the seismicity of
the area between the Hyblean-Malta fault system and the accretionary prism of the
Calabrian Arc are unknown. This experiment allows us to test the pressure waves detection
system that will be implemented in the Tsunami Warning System INGV is
developing within the IOC-UNESCO “NEAMTWS” (North-East Atlantic, Mediterranean
and connected seas Tsunami Warning System). In this poster we describe the
technical features and the performance of the OBS’s, the deployment campaign, and
some seismic data recorded
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