1,720,986 research outputs found
Environmental performance of wood pellets' production through life cycle analysis
No full textForests play a key role as the source of an essential renewable material and/or fuel: wood. The aim of this study was to evaluate the environmental impacts related to high-quality pellet production for domestic heating following the LCA (life cycle assessment) methodology and considering a cradle-to-gate perspective in the Tuscany region. This is representative and interesting for Italian pellet factories and for similar factories located in Central Europe, considering the Italian contribution to the production capacity of that area. All of the activities involved, from wood extraction in no-industrial forests to packed pellet production, ready for delivery to final users, were taken into account. The environmental analysis was performed in terms of seven impact categories. The results showed how the most important environmental burdens are related to the use of electricity during pellet production, being responsible for more than 90% of the total in most of the impact categories. Operations carried out in the forest produce a minor part of the impact (from 1% to less than 10% depending on the category). Four different alternative scenarios for producing and supplying electricity and heat were proposed and investigated. Substitution of the boiler by a co-generation unit showed a substantial improvement in the environmental burdens
Forest operations in coppice: Environmental assessment of two different logging methods
No full textWood is a renewable resource and it actively contributes to enhance energy production under a sustainable perspective. However, harvesting, transport and use of wood imply several consequences and impacts on environment. There are different ways for managing forests dedicated to wood production and a sustainable approach is fundamental to preserve the resource. In this context, Life Cycle Assessment (LCA) is a useful tool for estimating the environmental impacts related to renewable resources. Traditional coppice is a common approach for forest management in several areas, including southern Europe and, specifically, Italy, Spain and the Balkans.Due to different terrain conditions, different types of forest operations are considered for wood extraction from coppices, where the main product is firewood used in domestic heating. The aim of this work was to compare the main common systems for firewood production in two different terrain conditions ('flat/low steep' and 'steep/very steep' terrains), in a representative environment for Mediterranean area, located in central Italy, by means of LCA. Seven different impact categories were evaluated in a cradle-to-gate perspective taking into account all the operations carried out from the trees felling to the firewood storage at factory.Results showed that the extraction phase was the most important in terms of environmental burdens in firewood production and the use of heavy and high-power machines negatively influenced the emissions compared with manual operations. Finally, considering the general low-inputs involved in wood production in coppice, the transport of workers by car to the work site resulted on consistent contributions into environmental burdens. An additional analysis about the modifications of CH4 and N2O exchanges between soil and atmosphere, due to soil compaction in the extraction phase, was made and based on bibliographic information. Results showed a sensible difference between disturbed and undisturbed soil
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
Identifying causes, dynamics and consequences of work accidents in forest operations in an alpine context
No full textIn a sustainable perspective, where wood harvesting and use perfectly respond to environmental needs, social sustainability and related health and safety of forest workers cannot be disregarded. The aim of this study was the analysis of the accidents records in public companies in the Province of Trento, in Northern Italy, regarding forest operations in the period 1995-2013. Several information were available thanks to the up-to-date accident books compiled by each company. With an average Frequency index in the examined period of 88 injuries per million hours worked, forest operations were confirmed as one of the most dangerous works along all productive sectors. Monday had a significant higher frequency of accidents comparing to the other weekdays. The age of the workers seemed influencing the recovery period after injuries, which exponentially increase at rising age. Felling and processing definitely resulted as the most dangerous activity in forest operations covering the 31% of total accidents happened. 'He puts a foot wrong...', 'He was hit by...' were the most common phrases used in describing the studied accidents; these were the action cause of the accident and contribute explaining why body extremities, first of all the hands, were the body parts most injured. Finally, a new concept in accident analysis was proposed introducing the analysis of 'recidivism', which analysed the eventual recurrence of accidents to the same worker in a given period. Results have underlined that some workers had more than one injury during the analysed period, up to seven accidents for one of them
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
A methodological approach exploiting modern techniques for forest road network planning
Full text linkA well-developed road network allows all forest activities, including wood harvesting, firefighting and recreational activities. However, forest road construction and maintenance involve economic and environmental costs. For these reasons, forest road network planning is a fundamental phase of forest management, maximising the benefits and reducing costs and impacts. Thanks to modern technologies in data collection both for terrestrial and forest characteristics, new methods and tools have been developed to improve and facilitate road planning. The aim of this study was the development of a Decision Support System for helping managers during forest road network planning, exploiting Multi-Criteria Analysis, an Analytic Hierarchy Process and Geographic Information Systems. Three steps characterised the study: Þ an in-depth survey of the existing forest road network Þ an accessibility evaluation, based on a commonly applied Italian definition, taking into account the morphological characteristics of the land Þ an estimation of the accessibility requirements through the analysis of experts’ opinions, defined as Road Needs Index, based on different factors These phases were applied to a forest property located in northern Italy, and some improvements were proposed simulating a manager’s approach during planning. The results showed interesting features in accessibility evaluation, which identified three different classes of accessibility, represented in a map. The estimation of Road Needs Index assigned a class regarding road requirements to each forest management unit: »low«, »medium«, »high« and »very high«. This information was merged, becoming a useful tool to identify the forest areas with the highest problems in relation to the forest road network
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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