1,721,077 research outputs found
Greenhouse gas emissions, life cycle inventory and cost-efficiency of using laminated wood instead of steel construction
No full textThis article compares the use of glulam beams at the new airport outside Oslo with an alternative solution in steel in order to (1) make an inventory of greenhouse gas (GHG) emissions and energy use over the life cycle of glulam and of steel, (2) calculate the avoided GHG emissions and the cost of the substitution, and (3) analyse which factors have the strongest influence on the results. Compared to previous analyses of substitution between steel and glulam related to greenhouse gas emissions, this article brings in three new methodological elements: combining traditional life-cycle analysis with economic costs, considering explicitly the emissions’ points in time, and using discounted global warming potential (DGWP).The total energy consumption in manufacturing of steel beams is two to three times higher and the use of fossil fuel 6–12 times higher than in the manufacturing of glulam beams. Manufacturing of steel in the most likely scenario gives five times higher GHG emissions compared to manufacturing of glulam beams. Waste handling of glulam can either be very favourable or unfavourable compared to steel depending on the glulam being landfilled or used for energy production. Other assumptions that substantially affect the results over the life cycle are carbon fixation on the forest land that is regenerated after harvesting, whether the steel production is scrap-based or ore-based, and which energy sources are used for producing the electricity used by the steel industry. The uncertainty in the inventory data for glulam do not influence the results much compared to changes in these main assumptions. The glulam construction cannot be more than 1–6% more expensive than steel before the price per ton avoided greenhouse gas emissions becomes high compared to the present Norwegian CO2-tax on gasoline. In the most likely scenario, and not including carbon fixation on forest land, 0.24–0.31 tons of CO2-equivalents per cubic metre input of sawn wood in glulam production is avoided by using glulam instead of steel, whereas this figure increases to 0.40–0.97 t/m3 if carbon fixation on forest land is included. Using DGWP does not influence the results of the analysis significantly
Environmental and economic impacts of substitution between wood products and alternative materials
No full textThis article gives a state of the art overview on quantitative analyses from Norway and Sweden of Life cycle analyses (LCA), which compare the environmental impacts of substitution between wood and alternative materials, with emphasis on greenhouse gas (GHG) emissions, economics and methodological issues. In all studies referred to this overview, wood is a better alternative than other materials with regard to GHG emissions. Furthermore, wood is causing less emissions of SO2 and generates less waste compared to the alternative materials. Preservative treated wood, on the other hand, might have toxicological impacts on human health and ecosystems. Impacts on acidification, eutrofication and creation of photochemical ozone vary in different comparisons. Amount of greenhouse gases avoided due to substitution between wood and steel is in the range of 36–530 kg CO2-equivalents per m3 input of timber with 4% discount rate; depending on waste management of the materials, and how carbon fixation on forest land is included. This amount is 93–1062 kg CO2-equivalents for substitution between wood and concrete, if the wood is not landfilled after use. Many of the LCAs could be considerably improved, if the analyses were done with several alternative assumptions regarding boundaries of the system used in the LCA. This is important, not least to map what are the main assumptions for the results obtained and to compare with other studies. It is also important to consider the time-profile of the GHG emissions and other impacts over the life-cycle—it is surprising that this is not taken more seriously. Wood as a building material is competitive on price in those studies that include costs. It is a weak point of many LCAs that costs as well as other economic aspects influencing product substitution are not included, and a major research challenge is to combine traditional LCA with economic analysis in order to make both more policy relevant. In particular, one should develop dynamic input/output models where price and income substitutions as well as technological changes and cost components are included endogenously
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
Forest-related policies affecting bioenergy markets in Europe
No full textThe increasing interest in the use of forest biomass as a renewable energy source has activated policy developments at all geographical levels from international and national to local. Given their high relevance for actors in the sector we focus in this chapter on giving an overview of policies at the EU level that are relevant for the development of sustainable biomass energy from forests. These include: forest, climate, energy, rural development and trade policies, as well as synergies and connections among them
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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