1,721,314 research outputs found
Bioenergy futures: a global outlook on the implications of land use for forest-based feedstock production
No full textInternalizing the external costs of biogas supply chains in the Italian energy sector
Full text linkIn Italy biogas support schemes are being revised to include subsidies for the production of biomethane. Energy policies should foster environmentally optimal solutions, especially because social acceptance issues often arise in the case of biogas. In this paper we use the external cost methodology to quantify the environmental impact of airborne emissions associated with biogas-based energy vectors and their corresponding fossil substitutes These are evaluated at supply chain level and incorporated in a spatially explicit optimization model. The method is applied to northern Italy to compare the potential impact of alternative policy options. It is found that, while the external costs of biogas-based pathways are always lower than corresponding fossil fuel based pathways, the differences are generally so small that policies based on internalization of external costs alone would not lead to further development of biogas-based technologies. For all utilization pathways, consideration of local externalities leads to a less favourable evaluation of biogas-based technologies, which results in external costs even higher than the substituted fossil fuel if biogas is allocated to local heating
Biomethane as transport fuel - A comparison with other biogas utilization pathways in northern Italy
No full textItaly is a large producer of biogas from anaerobic digestion, which is mainly used for power generation with limited use of cogenerated heat. Other utilization pathways, such as biomethane injection into the natural gas grid or biomethane used as a vehicle fuel, remain unexplored. Given the dense grid of natural gas pipelines and existing Compressed Natural Gas (CNG) refueling stations in northern Italy, significant market opportunities for biogas could also arise in the heating and transport sectors. The main objectives of this paper are to explore the potential role of agricultural biogas in different utiliztion pathways. Biogas combustion for simultaneous production of heat and power in small Combined Heat and Power (CHP) facilities is also assessed, as is upgrading to biomethane for transport or natural gas grid injection in the specific context of northern Italy. The spatially explicit optimization model BeWhere is used to identify optimal locations where greenfield biogas plants could be installed and to determine the most economic and environmentally beneficial mix of conversion technologies and plant capacities. Carbon price, for instance in the form of tradable emission permits, is assessed as a policy instrument and compared with other options such as price premiums on biomethane or electricity costs. Results show that starting from a carbon price of 15 EUR/tCO2, the cogeneration option is preferable if plants are located in the proximity of existing district heating infrastructure. CNG plants are only competitive starting at a carbon price of 70 EUR/tCO2 in areas with high feedstock availability. The sensitivity analysis for energy prices reveals that a larger number of CNG facilities are included in the optimal mix at higher gas wholesale prices. This further indicates that specific premiums are neeeded to expand the biomethane market share, while greenhouse gas emission reductions would primarily be achieved by fostering cogeneration of electricity and heat supported by carbon price-basd policy instruments
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
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
Management of non-native tree species in forests of the Alpine space
Full text linkThis guide was prepared within the framework of the project ALPTREES (code ASP791), which is co-funded by the European Commission through the INTERREG Alpine Space financial mechanism. The INTERREG Alpine Space programme is a European transnational cooperation programme for the Alpine region. It provides a framework for facilitating cooperation between key economic, social, and environmental players in seven Alpine countries, as well as between various institutional levels. The programme is financed through the European Regional Development Fund (ERDF) as well as through national public and private co-funding in the Partner States
- …
