Effect of coil charge duration on combustion variability and flame morphology in a GDI engine working in lean burn conditions

Spark ignition (SI) and subsequent flame front development exert a significant influence on cyclic variability of internal combustion engines (ICEs). The increasing exploitation of lean air-fuel mixtures in SI engines to lower fuel consumption and CO2 emissions is driving the scientific community towards the search for innovative combustion strategies. Moreover, although lean combustion has been widely investigated and an important number of studies is already present in literature, the high cyclic variability typical of this combustion process still represents a major hinder to its exploitation. This study aims to investigate the effects of increasing ignition energy on combustion characteristics of lean mixtures. Tests were performed on an optically accessible gasoline direct injection (GDI) engine that allowed to investigate the correlation between the thermodynamic results and spark arc-flame morphology. Engine speed was fixed at 2000 rpm, a relative air fuel ratio (AFRrel) of about 1.3 was selected and ignition timing was set at 12 crank angle degrees (CAD) bTDC. Coil charge duration was swept from 10 to 40 CAD. Two intake pressure levels were investigated, the first corresponding to wide open throttle under naturally aspirated operating mode, the second with an intake pressure of 1.2 bar, thus corresponding to a boosted operating condition. Two dedicated scripts built using NI Vision were employed for image processing, allowing the evaluation of temporal and spatial evolution of the early stages of combustion. Arc elongation and flame front contour were used as correlation parameters that characterize flame kernel inception and development. The results confirm that, as expected, the increase of the coil charge duration tends to reduce cyclic variability in terms of engine output. The optical investigations revealed that for both examined cases the standard deviation related to the wrinkling effect on flame edge at CA5 decreased as the coil charge duration increased

Year-round variation in the isotopic niche of Scopoli's shearwater (Calonectris diomedea) breeding in contrasting sea regions of the Mediterranean Sea

Top marine predators are key components of marine food webs. Among them, long-distance migratory seabirds, which travel across different marine ecosystems over the year, may experience important year-round changes in terms of oceanographic conditions and availability of trophic resources. We tested whether this was the case in the Scopoli's shearwater (Calonectris diomedea), a trans-equatorial migrant and top predator, by sampling birds breeding in three environmentally different regions of the Mediterranean Sea. The analysis of positional data and stable isotopes (δ1³C and δ15N) of target feathers revealed that birds from the three regions were spatially segregated during the breeding period while they shared non-breeding areas in the Atlantic Ocean. Isotopic baseline levels of N and C (meso-zooplankton) were significantly different among marine regions during breeding. Such variation was reflected at the higher trophic levels of pelagic and demersal fish muscles as well as in shearwater feathers grown in the Mediterranean. δ15N- and δ13C-adjusted values of shearwaters were significantly different among populations suggesting that birds from different breeding areas relied on prey species from different trophic levels. Conversely, the non-breeding spatial and isotopic niches overlapped greatly among the three populations. Shearwater trophic niches during breeding were narrower and segregated compared to the non-breeding period, revealing a high plasticity in trophic resource use. Overall, this study highlights seasonal and region-specific use of trophic resources by Scopoli's shearwater, suggesting a broad trophic plasticity and possibly a high adaptability to environmental changes

The INGV Mobile Telemetered Network (Re.Mo.Tel.): long-term monitoring analysis.

Since 2008, the Istituto Nazionale di Geofisica e Vulcanologia (INGV) developed a temporary real-time telemetered seismic network infrastructure (Re.Mo.Tel.) to densify the Italian National Seismic Network in epicentral area, thus improving the location of the aftershocks distribution after a mainshock. This infrastructure consists of various mobile and autonomous seismic stations that in group of three are telemetered to a Very Small Aperture Terminal (VSAT). Using a dedicated bandwidth on UHF, Wi-Fi and satellite frequency, the system is able to stream real-time data to the INGV acquisition centers in Rome and Grottaminarda. The deployment of the seismic network is supported by a geographical information system (GIS) that visualizes, for the epicentral area, information about instrumental seismicity, seismic risk, macroseismic felts and territorial data. The April, 6th, 2009 Mw 6.3 L'Aquila destructive earthquake represented the first real-case where the entire Re.Mo.Tel. infrastructure has been deployed. Less than 6 hours after the earthquake occurrence, a first accelerometric station was streaming data to the INGV seismic monitoring headquarters. A total number of 9 seismic stations was installed within 4 days after the main event, with the aim of recording continuous data to contribute in the aftershocks detection. In detail the first day a number of 3 stations was installed, surrounding the mainshock. Then the rest of the stations was deployed on the third and the fourth day to the south and the north, following the post-seismic evolution. A project funded by the Dipartimento di Protezione Civile (DPC-Civil Defense) gave the opportunity to maintain some of the deployed stations throughout the duration of the project of one year (although the stations are still installed) to assure the long-term monitoring of the triggered seismic sequence. In this work, we investigate: • The impact of the Re.Mo.Tel. on earthquakes detection and real-time monitoring of the sequence evolution; • The location improvement due to the deployment of stations closer to the epicentral area (with installations that followed the early evolution and complexity of fault fractures); • The network reliability in terms of data stored throughout the working period

Seismic activity in the Pollino region (Basilicata-Calabria border)

The Pollino region and the whole Calabria-Lucania border are known for the absence of destructive (M>6) historical earthquakes. This lack of historical seismicity is noticeable in the analysis of Southern Apennines and Calabria earthquake history (Rovida et al., 2011). At the same time, paleoseismological studies found evidence for significant active faulting (Cinti et al., 1997; Michetti et al., 1997) pointing to the Pollino area as a seismic gap. Instrumental seismicity in the region is characterized by the occurrence of seismic sequences, one of the most significant in the last decades is the Mercure seismic sequence, Mw 5.6 in September 1998 (Brozzetti et al., 2008). For this reason, the sequence started in 2010 raised a big concern in the population and local authorities. INGV is following the evolution of the sequence since its beginning, in March 2010, increasing the seismic monitoring and planning several activities and projects. The area was proposed by INGV to DPC (Dipartimento di Protezione Civile nazionale) for inclusion in the projects to be carried out in the present INGV-DPC agreement. This project has just started and will try to provide better constraints to the active tectonics and fault identification of the region. In this paper we describe what INGV is doing to understand better the tectonics of the region using microseismicity, and try to offer some cue to the discussion about the seismogenic faults in the area.Published5-92T. Tettonica attivaN/A or not JCRope

Sex-mediated changes in foraging behaviour according to breeding stage in a monomorphic seabird adapted to rural habitats

In contrast to sexually size-dimorphic species, monomorphic ones rarely show sexual differences in foraging behaviour as such variations have been primarily attributed to dissimilar body size. To investigate this aspect, we analysed foraging behaviour in breeding gull-billed terns, Gelochelidon nilotica, a monomorphic seabird adapted to rural habitats. We equipped 19 breeding birds with GPS devices and assessed differences in foraging behaviour and habitat use according to sex and breeding stage. Foraging trip distance and duration and daily frequencies were influenced by both breeding stage and sex, with females, but not males, performing closer, more frequent and shorter duration trips during chick rearing than incubation. Females, but not males, increased the repeatability of foraging metrics from incubation to chick rearing, while both sexes increased individual foraging site fidelity between the two breeding stages. Agricultural fields were the most exploited habitat for both sexes, but females made more use of aquatic habitats than males, especially during chick rearing. By foraging in different ways and in different habitats, the breeding pair can provide a wider range of prey types to their offspring, maximizing the chances of delivering high quantity and quality of food items under different environmental conditions. Our work provides new additional evidence of sex differences in foraging behaviour of monomorphic species, while highlighting the need to better understand underlying mechanisms driving foraging niche divergence and the consequences for fitness

La Rete sismica Mobile in telemetria satellitare (Re.Mo.Tel.)

Oggi la nuova Rete Sismica Mobile in telemetria satellitare” (Re.Mo.Tel.) è composta da nove stazioni la cui trasmissione, tramite ponte UHF (Ultra High Frequency), è equamente ripartita verso tre centri di acquisizione intermedi, detti “sottonodi”). Tali sottonodi, a loro volta tramite connessione Wi-Fi, ridirezionano il flusso dati verso un “centro stella” (detto “nodo”) dal quale, con il sistema di trasmissione satellitare Libra VSAT Nanometrics, i dati sono inviati al centro acquisizione dati della Sala Sorveglianza Sismica della sede INGV di Roma e ridondati al centro “disaster recovery” approntato presso l’Osservatorio di Grottaminarda (Sede Irpinia in provincia di Avellino). La struttura della Re.Mo.Tel. è stata ideata ed ingegnerizzata in modo da ridurre al minimo i tempi d’installazione. Il sistema è stato infatti realizzato interamente “plug and play” e di conseguenza nessuna attività di configurazione è richiesta all’operatore all’atto dell’istallazione. La Re.Mo.Tel. si basa su di un articolato sistema di trasmissione (UHF, Wi-Fi e satellitare), mediante l’impiego di diversi apparati

The INGV-CNT crustal motion map for the Euro-Mediterranean region

Several thousands GPS/GNSS permanent stations, managed by both scientifc and cadastral institutions, are now available on the European plate and its boundaries. Data coming from these stations provide unprecedented spatial and temporal coverage of time-dependent deformation signals essential to understand the fundamental physics that govern tectonic deformation and faulting. The National Earthquake Center (Centro Nazionale Terremoti, CNT) of the National Institute of Geophysics and Volcanology (Istituto Nazionale di Geofisica e Vulcanologia, INGV) in Italy, is the Italian leader institution for the collection, management and scientific analysis of Global Positioning Systems (GPS) measurements. Distinct analysis centers independently and routinely process and analyze data using high-quality geodetic software (Bernese, Gamit, Gipsy) to measure the movements of >1000 points spanning the Eurasian plate and its boundaries. The goal of this project is to offer high-quality geodetic products, increase their accessibility to the European scientific community and promote the inter-disciplinary data exchange through a multi-level, user-friendly data gateway. These activities will be performed in strict contact with the GNSS Working Group of the EPOS project (http://www.eposeu.org) that is proposing to integrate, archive and distribute data, metadata and products for available GNSS stations on the European plate.PublishedVienna, Austria2T. Tettonica attivaope