1,720,962 research outputs found
Woody biofuel production from short rotation coppice in Italy: Environmental-impact assessment of different species and crop management
No full textShort Rotation Coppices (SRC) can be a suitable solution for the production of biomass, mainly due to the
easy-to-harvest good-quality feedstock. Besides technical, social and economic aspects, environmental
issues are important to be taken into account when developing SRC. Although some studies focused on
environmental sustainability of SRC were carried out only few compare different arboreous species using
primary data.
In this study, the environmental evaluation of SRC plantations carried out with 14 poplar and 6 willow
clones was performed using primary data collected during experimental field tests over 12 years.
Twelve impact potentials were evaluated using the characterization factors reported by the ILCD
method: climate change (CC), ozone depletion (OD), Human toxicity, cancer effects (HTc), Human
toxicity, non-cancer effects (HT), particulate matter (PM), photochemical ozone formation (POF), acidi-
fication (TA), freshwater eutrophication (FE), terrestrial eutrophication (TE), marine eutrophication (ME),
freshwater ecotoxicity (FEx) and mineral, fossil and renewable resource depletion (MFRD).
Both for poplar and for willow, among the different clones the environmental performance greatly
vary mainly due to the yield. The choice of the most productive clones involves a reduction of the
environmental impact of the produced biomass of about 35% (respect to the average results both for
poplar and willow). However, biofuel production from willow SRC achieves lower environmental burdens
respect to poplar SRC considering both the average biomass yield and the most productive clones
Aboveground biomass estimation for Italian poplar SRF
No full textOne critical aspect for operators of the wood energy market is the quantification of above ground
biomass production in establishing contracts before harvest. The preparation of a biomass regression equation for
individual SRF yield is expensive and time-consuming for most operators. The aim of this study is to develop
equations for a non-destructive estimation of biomass yields easy to use. The data collected were utilized to develop
exponential functions in the form W = bDC (where W is the total shoot wet or dry weight and D is the diameter at
breast height) that give a reasonable estimate of above ground biomass for individual shoots.
Keywords: biomass production, energy crops, poplar
Biomass production in mixed plantation with SRC and noble hardwoods
Full text linkA new model of cultivation that combines reforestation with noble hardwood species (Maple, Cherry,
Service and Wild Service Trees, etc) and Short Rotation Coppices (SRC) with poplar, willow and black locust was
studied in Italy. This paper refers the results obtained during the first 2-4 years of growth. If correctly grown, the
clones of poplar and willow selected for biomass can assure good productions up to 8-9 Odt·ha-1·year-1. The poplar
and willow clones had shown a different behavior depending on the pedological and climatic characteristics of the
sites, therefore it will be necessary to carefully choose the clones to insert in the stand. On a Piedmont sites,
characterized by marginal soil for the agriculture, also the Black Locust has given good results of growth and
production: 4 Odt·ha-1·year-1. The interaction among the intercalary SRC and the noble hardwood plants still have not
been put in evidence from the statistical analysis
Biomass production and energy balance of herbaceous and woody crops on marginal soils in the Po Valley
Full text linkA wealth of data and information on the cultivation of perennial biomass crops has been collected, but direct comparisons between herbaceous and woody crops are rare. The main objective of this research was to compare the biomass yield, the energy balance and the biomass quality of six perennial bioenergy crops: Populus spp., Robinia pseudoacacia, Salix spp., Arundo donax, Miscanthus × giganteus, and Panicum virgatum, grown in two marginal environments. For giant reed and switchgrass, two levels of nitrogen fertilization were applied annually (0-100 kg ha-1). Nitrogen fertilization did not affect biomass or energy production of giant reed; thus, it significantly reduced the energy return on investment (EROI) (from 73 to 27). In switchgrass, nitrogen fertilization significantly increased biomass production and the capacity of this crop to respond to water availability, making it a favorable option when only biomass production is a target. Net energy gain (NEG) was higher for herbaceous crops than for woody crops. In Casale, EROI calculated for poplar and willow (7, on average) was significantly lower than that of the other crops (14, on average). In Gariga, the highest EROI was calculated for miscanthus (98), followed by nonfertilized giant reed and switchgrass (82 and 73, respectively). Growing degree days10 during the cropping season had no effect on biomass production in any of the studied species, although water availability from May to August was a major factor affecting biomass yield in herbaceous crops. Overall, herbaceous crops had the highest ranking for bioenergy production due to their high biomass yield, high net energy gain (NEG), and biomass quality that renders them suitable to both biochemical and thermochemical conversion. Miscanthus in particular had the highest EROI in both locations (16 and 98, in Casale and Gariga), while giant reed had the highest NEG on the silty-loam soil of Gariga
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
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