1,720,966 research outputs found
Analysis of current aviation biofuel technical production potential in EU28
Full text linkThe significant growth aviation has been observing is increasing the sector's pressure on the environment; in the EU28, passengers travelling by air in 2016 increased of 5.9% compared to 2015. The aviation industry voluntarily committed to significant aspirational goals, and identified bio-based aviation fuels as a potential means to improve its environmental performance. Despite of that, the market penetration of aviation biofuels in EU28 is almost negligible. In this paper, an assessment of the likely aviation biofuels demand has been carried out, under a baseline scenario of increasing total fuel consumption of +3% for 2016–2020 and + 3.5% up to 2030; the CO2 intensity of this growth has been calculated accordingly. Europe is a World leader in biofuel technologies; the current potential aviation biofuels is based on the HVO/HEFA technology, and the upper limit of the installed capacity can be considered approximately 2.4 Mt y−1. Nevertheless, lower production volumes can be expected as production plants are today optimized for road fuel production, not aviation. By 2025 the situation may change, with a total production capacity of 3.5 Mt y−1, and with an average potential production for aviation biofuels ranging 0.5–2 Mt y−1. The paper shows that even if today's EU nominal capacity appears large enough to support the expected aviation biofuels demand, other bottlenecks may limit the real market uptake: availability of sustainable feedstocks, competition with demand for road transport sector, etc. For this reason, a comparison of the cost for CO2 saving of other potential solutions to mitigate aviation's climate impact has also been carried out
Passenger Aviation and High Speed Rail: A Comparison of Emissions Profiles on Selected European Routes
Full text linkAir transport has been constantly growing and forecasts seem to confirm the trend; the resulting environmental impact is relevant, both at local and at global scale. In this paper, data from various datasets have been integrated to assess the environmental impact of modal substitution with high speed rail. Six intra-EU28 routes and a domestic route have been defined for comparison. The airports have been chosen considering the share of the total number of passengers on flights to/from other EU Member States. Three scenarios have been proposed in the time period 2017–2025; aircraft types, distance bands, and occupancy rate are investigated on each scenario. The comparison with HSR service has been carried out only on passenger service and not for freight. The energy consumption and the consequent emissions for the aircraft have been estimated on the base of the available data for the mix of aircraft types, performing the routes. The results indicate the advantage of the high speed trains, in terms of direct CO2eq emissions per passenger km. Compared to a neutral scenario, with an annual passenger increment of 3.5%, the HSR substitution of the 5% and the 25% of this increment allow a GHG saving of 4% and 20%, respectively. Some of the analysed routes (e.g., Frankfurt Main–Paris CDG) have interesting GHG savings but the duration of the trip today is limiting for a real substitution. Moreover, there is general agreement that the extreme weather events induced by climate change will affect the functioning of the European transport system. In this sense, transportation by the rail mode is expected to play a significant role in strengthening the EU transport system, its resilience, and its reliability, as it is less immediately subject to the impacts of severe weather conditions
Could Biomass Derived Fuels Bridge the Emissions Gap between High Speed Rail and Aviation?
Full text linkAviation is a steadily growing sector, which largely contributes to transport greenhouse gas (GHG) emissions. When High Speed Rail (HSR) and aviation are considered as alternative options, HSR proves to be a more environmentally friendly mode of transport. Public available data have been used in order to calculate the emission profiles on two selected intra-European routes (London-Paris and Frankfurt-Amsterdam) by HSR and air. As expected, the air mode results in higher GHG emissions and solutions for mitigating its impact have been analyzed and suggested. Biomass Derived Fuels (BDF) has a limited, up to now, potential, to fill the existing gap in terms of emissions with rail. Moreover, BDF reduction in GHG emissions is accompanied with by an increase in fuel cost. Finally, the cost per tonne of avoided CO 2eq by using BDF-which values 186 €/t-has been compared with the prices of the European Union (EU) Emission Trading System (ETS) allowances and, from a purely economic perspective, this market based measure still seems a preferable option to curb the GHG emissions of the air mode. © 2019 by the author
Biomethane as alternative fuel for the EU road sector: analysis of existing and planned infrastructure
Full text linkThe views expressed here are purely those of the authors and may not, under any circumstances, be regarded as an official position of the European Commission
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Review of technologies for biomethane production and assessment of Eu transport share in 2030
Full text linkThe upgrade to biomethane allows extending biogas applications to transport sectors, supporting EU goals toward carbon neutrality. Biomethane produced from biogas upgrading can today rely on a large number of plants, estimated by the European Biogas Association in over 17000 in 2016, for a total installed capacity of 9985 GW (EBA, 2017). After 2020, biogas and biomethane will count towards the 32% target of renewable energy share of the EU energy consumption, and towards a sub-target of minimum 14% of the energy consumed in the transport sector by 2030 (REDII). In this framework, the paper aims to define the current market penetration of biogas upgrading technologies. A database has been created for EU-28, to highlight the relative importance of each technology. Based on the database, a EU production potential is defined, along with the EU demand potential for transport, in order to verify the match between supply and demand. The analysis of the current state of play of the sector suggests that a large potential can be foreseen for near future; the expected increase in biomethane production is based also on the possibility to convert residual feedstocks, such as Municipal Solid Wastes. In this work a moderate technology penetration scenario has been set for EU-28, reaching a potential for biomethane of 18 billion m 3 /year in 2030. A large share of this potential can be devoted to transport, with a relevant impact on the sector. LNG appears suitable for pushing the market uptake of biomethane in the transport sector. Among the potential uses of biomethane for transport, it is worth considering that the natural gas use in the maritime and internal waterways sectors is getting momentum. The current analysis aimed to highlight the potential of renewable energy-based alternatives to natural gas. Eventually, it is worth noticing that the real market deployment of this potential will be determined by the energy market conditions, and by the member states capability to stimulate the industry through a coherent set of supporting initiatives
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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