5 research outputs found

    fUel-SAVing trip plannEr (U-SAVE): a product of the JRC PoC Instrument: Final report

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    Available tools for trip planning mostly rely on travel time and travel distance. Fuel costs, when taken into account, are based on simplified fuel consumption models and are usually independent from vehicle type and technology. Building on the work carried out by the Sustainable Transport Unit of the Joint Research Centre, European Commission, in developing (a.) CO2MPAS, the official tool supporting the WLTP/NEDC Correlation Exercise and allowing the back-translation of a WLTP test to the equivalent NEDC CO2 emission value during the type approval, and (b.) Green Driving, an interactive web-based tool allowing the estimation of fuel costs and CO2 emissions of individual car journeys on the basis of variables such as car segment, engine power, fuel type and driving style, the present project aimed at developing and proving the concept of a routing machine to be used when fuel consumption minimization is considered. Throughout the project a stand-alone off-board trip planner has been developed, the U-SAVE Desktop Version, while a smartphone application, the U-SAVE Navigation Application, is currently under the last development phase, and shall be used once completed as a low cost in-board navigation system. The tool has been extensively validated internally demonstrating both its capability to accurately estimate fuel and energy consumption via alternative trip options, and its capacity to provide a more efficient route when different from the shortest and/or fastest options. An open-access version of the tool is expected to become a reference instrument for private citizens who are concerned about their fuel consumption and a more efficient use of their vehicles, while a premium API-based commercial version of the tool can operate as a viable and scalable business model targeting, among others, established navigation software providers who want to extend their offering by providing an alternative route option to their clients, mainly private companies managing fleets of light-duty vehicles, for whom saving fuel from the daily vehicle operations is of crucial financial importance.JRC.C.4-Sustainable Transpor

    The Nature of Optically Dull Active Galactic Nuclei in COSMOS

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    We present infrared, optical, and X-ray data of 48 X-ray bright, optically dull AGNs in the COSMOS field. These objects exhibit the X-ray luminosity of an active galactic nucleus (AGN) but lack broad and narrow emission lines in their optical spectrum. We show that despite the lack of optical emission lines, most of these optically dull AGNs are not well-described by a typical passive red galaxy spectrum: instead they exhibit weak but significant blue emission like an unobscured AGN. Photometric observations over several years additionally show significant variability in the blue emission of four optically dull AGNs. The nature of the blue and infrared emission suggest that the optically inactive appearance of these AGNs cannot be caused by obscuration intrinsic to the AGNs. Instead, up to ~70% of optically dull AGNs are diluted by their hosts, with bright or simply edge-on hosts lying preferentially within the spectroscopic aperture. The remaining ~30% of optically dull AGNs have anomalously high f_x/f_o ratios and are intrinsically weak, not obscured, in the optical. These optically dull AGNs are best described as a weakly accreting AGN with a truncated accretion disk from a radiatively inefficient accretion flow.Comment: 12 pages, 10 figures. Accepted for publication in the Ap

    Tools for Customized Consumer Information on Vehicle Energy Consumption and Costs - A European Case Study

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    The European Commission’s Joint Research Centre, in line with the European Strategy for Low-Emission Mobility, has launched in 2016 the Green Driving Tool, an interactive web-based tool aiming at estimating fuel costs and CO2 emissions of individual car journeys. In parallel, it has developed U-SAVE, a routing system for fuel-efficient trip planning aiming at fuel consumption minimization and vehicle specific calibration. This paper provides a first assessment of the performance of the two tools in predicting fuel consumption and CO2 emissions over real-world trips. The analysis focused on the accuracy and uncertainty of the two tools when varying the detail of vehicle input data and of the velocity profile used in the calculation. These elements are particularly important in case of future integration of the tools with traffic simulation models where the level of detail regarding the vehicle input or the speed profile may vary. Results show that U-SAVE prediction is positively affected by the detail of vehicle specifications, while is not significantly sensitive to the detail of the velocity profile. Contrary, Green Driving didn’t show any remarkable change when varying both parameters. Overall, U-SAVE demonstrates a good performance in predicting CO2 emissions over on-road tests reaching an average prediction accuracy over an entire test trip of -4.6% and a standard deviation of 5.2%, while Green Driving exhibit higher uncertainty (on average 12%) but lower bias which ranged in the order of 0 to +3% depending on the vehicle and the test trip considered.JRC.C.4-Sustainable Transpor

    Geochronology of Metasomatic Events

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    In order to date any geological event, suitable mineral geochronometers that record that and only that event must be identified and analyzed. In the case of metasomatism, recrystallisation is a key process that controls both the petrology and the isotopic record of minerals. It can occur both in the form of complete neocrystallisation (e.g. in a vein) and in the form of pseudomorphism, whereby dissolution/reprecipitation at the submicroscopic scale plays a central role. Recrystallisation may be complete or not, raising the possibility that relicts of a pre-metasomatic assemblage may be preserved. Because recrystallisation is energetically less costly at almost any temperature than diffusion, and because radiogenic isotopes (except 4He) never diffuse faster than major elements forming the mineral structure, there is a strong causal link between petrographic relicts and isotopic inheritance (as demonstrated for zircon, monazite, titanite, amphibole, K-feldspar, biotite, and muscovite). Metasomatic assemblages commonly contain such mixtures between relicts and newly formed phases, whose geochronology is slightly more complex than that of simple, ideal systems, but can be managed by techniques that have become routine in the last decade and which are described in this chapter. Because of its crucial role in controlling the isotope systematics, the petrogenesis of a mineral needs to be understood in extreme detail, especially using microchemical analyses and micro-imaging techniques, before mineral ages can be correctly interpreted. As the occurrence of recrystallization is limited by the availability of water, minerals act as “geohygrometers” that allow constraints to be placed on the nature and age of fluid circulation episodes, especially metasomatic events
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