1,720,966 research outputs found
Advancing on comparability aspects for Product and Organisation Environmental Footprint
Full text linkThe Environmental Footprint (EF), with its Product and Organisation Environmental Footprint (PEF and OEF), is the method adopted by the European Commission to assess the environmental impacts of products, services, and organisations throughout their life cycle. Granting comparability of EF results is a key objective, in particular thanks to the definition of PEF category rules (PEFCRs) and OEF sector rules (OEFSRs). However, as following the experiences during the EF pilot phase (2014-2018), several issues relating to comparability call for more detailed guidance. Building on the existing Recommendation (EU) 2021/2279, we analysed further on: how to compare environmental impacts of organisations; how to compare environmental impacts of intermediate products; and how best define granularity of PEFCRs and OEFSRs. Each of these topics is discussed in a separate chapter of the report
Valorization of alginate for the production of hydrogen via catalytic aqueous phase reforming
No full textAlginate, a carbohydrate abundant in the outer cell wall of macroalgae, was subjected to catalytic aqueous phase reforming (APR) to produce hydrogen using a 3% Pt/C commercial catalyst. The performance of the process was evaluated according to the conversion of the carbon to gas, the hydrogen yield and the hydrogen selectivity. The catalyst and feed amount, temperature, reaction time, pH and the presence of H2were modified to understand the dependence of the outcome of the process on these parameters. The presence of the catalyst was fundamental in order to increase the hydrogen yield compared to the uncatalyzed reaction, and it can be reused without activity loss. In addition, it was observed that the increase in alginate loading led to a decreasing conversion of the carbon; the yield of hydrogen increases with the increasing temperature and the basic pH had a strong beneficial effect in terms of selectivity. The plateau appeared after 2 h was attributed to the low kinetic tendency of the intermediate compounds to produce hydrogen. The study validated what is present in literature for simpler molecules, moving at the same time towards a more complex feed, closer to a possible industrial application
Safe and Sustainable by Design chemicals and materials - Methodological Guidance
Full text linkThis Methodological Guidance clarifies some aspects of the voluntary application of the "safe and sustainable by design" (SSbD) framework for chemicals and materials. It combines the disciplines of "Risk Assessment" (RA) and "Sustainability Assessment" (SA), which have different methodologies, framing and terminology. This Methodological Guidance explains the rationale of the framework and replies to the feedback collected during several stakeholder consultations, which have contributed to its progressive refinement. It furthermore presents a method for scoping analysis and discusses why it is important to correctly frame the subsequent SSbD assessment. Following on, thematic chapters specifically address aspects of the two domains of the framework: safety assessment and environmental sustainability assessment, and also address socio-economic assessment
Critical review of methods and models for biodiversity impact assessment and their applicability in the LCA context
Full text linkGlobal biodiversity is in rapid decline and halting biodiversity loss is one of the most important challenges humanity must tackle now and in the immediate future. The five main direct drivers of biodiversity loss are climate change, pollution, land use, overexploitation of resources and the spread of invasive species, which result from indirect drivers such as unsustainable production and consumption. It is therefore of paramount importance that scientifically robust methods are developed to capture impacts on biodiversity from a value-chain perspective. Life Cycle Assessment (LCA) methodology allows to quantify the impact of products and organisations throughout their whole life cycle. In the LCA framework, several methods for biodiversity impact assessment have been developed. Building on previous reviews, this article aims to critically analyse methods and models for biodiversity impact assessment in LCA and beyond as comprehensively as possible, and to select those that may be most suitable for application in an LCA context. 64 methods were reviewed and 23 were selected for a detailed analysis based on availability of documentation, domain of application, geographical scope, potential to be used in LCA, and added value. The analysis addressed their goal and scope, data use and needs, and impact assessment characteristics, revealing strengths and weaknesses of the methods. There is currently no method that takes well into account at the same time the variety of pressures on biodiversity, ecosystems, taxonomic groups, essential biodiversity variables classes, and the fundamental aspects to consider in biodiversity impact assessments – but for each of these five criteria, we show which methods perform best. For the future development of biodiversity impact assessment, it is required to improve the coverage of drivers of biodiversity loss, increase ecosystem and taxonomic coverage, include the assessment of ecosystem services, and develop robust indicators that allow for complementary analysis of more essential biodiversity aspects
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
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