1,721,026 research outputs found
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
Nutrients recovery from anaerobic digestate of agro-waste: Techno-economic assessment of full scale applications
Full text linkThe sustainable production of fertilizers, especially those based on phosphorus, will be one of the challenges of this century. Organic wastes produced by the agriculture, urban and industrial sectors are rich in nutrients which can be conveniently recovered and used as fertilizers. In this study five full scale systems for the recovery of nutrients from anaerobic digestate produced in farm-scale plants were studied. Monitored technologies were: drying with acidic recovery, stripping with acidic recovery and membrane separation. Results showed good performances in terms of nutrients recovery with average yields always over 50% for both nitrogen and phosphorus. The techno-economic assessment showed how the specificity of the monitored systems played a major role: in particular, membranes were able to produce a stream of virtually pure water (up to 50% of the treated digestate) reducing the digestate volume, while drying, because of the limitation on recoverable heat, could treat only a limited portion (lower than 50%) of produced digestate while stripping suffered some problems because of the presence of suspended solids in the liquid fraction treated. Specific capital and operational costs for the three systems were comparable ranging between 5.40 and 6.97 € per m3 of digestate treated and followed the order stripping > drying > membranes. Costs determined in this study were similar to those observed in other European experiences reported in literature
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
Hydrogen and Methane production from OFMSW and sewage sludge by two phases anaerobic codigestion.
No full textIn this paper a two-phase anaerobic codigestion of organic fraction of municipal solid waste and sewage sludge has been investigated experimentally. The aim of this work is to verify the feasibility and the performance of the process for the hydrogen and methane production. The experimental was carried out at pilot scale using two stirred reactors both maintained at thermophilic temperature (55°C) and fed semicontinuously with separate collected biowaste and sewage sludge. Nor chemicals neither recirculation were used to control the pH in first phase. The study lasted 50 days in which there were no evidences of any instability in the process.It was confirmed the possibility to obtain a stable hydrogen production with a specific average hydrogen production of 40 l per kg of total volatile solid (TVS) fed and a specific biogas production in the second phase of 0.32 m3per kgTVS fed.The biogas produced has a composition characterized by a stable presence of hydrogen over 5%. Therefore, the biogas produced meets the composition characteristic of biohythane
Pedagogical Documentation in the Era of Digital Platforms: Early Childhood Educators’ Professionalism in a Dilemma
No full textThe so-called logic of datafication and platformisation, as a consolidated business model for the BigTech industry with applications to education (van Dijck et al., 2018), can also reach (and affect) early education and care. In a kid’s culture that values documenting and sharing with parents, social media and instant messaging are widely used. Educators feel overloaded with the challenges posed by digital platforms, but contextual issues are relevant to finding ways for resistance and engagement in political actions to transform the edtech platforms’ dominance. Investigating the specific discourses and approaches to platformisation from early education professionals appears relevant to promoting not only awareness but also ways to rethink professional and political agency. Our preliminary study is based on 14 individual interviews and one group interview with educators in the Italian region of Veneto. The results of our thematic analysis indicate that achieving a balance between technology-based documentation and children’s privacy is not straightforward. Also, educators are calling for policies and further support for technology-driven services and activities that make thoughtful and conscious use of technology to avoid harming children. On these bases, we advance recommendations to deepen early childhood educators’ professional development requirements in a data-driven and post-digital society
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
Nutrients recovery from anaerobic digestate of agro-waste: Techno-economic assessment of full scale applications
No full textThe sustainable production of fertilizers, especially those based on phosphorus, will be one of the challenges of this century. Organic wastes produced by the agriculture, urban and industrial sectors are rich in nutrients which can be conveniently recovered and used as fertilizers. In this study five full scale systems for the recovery of nutrients from anaerobic digestate produced in farm-scale plants were studied. Monitored technologies were: drying with acidic recovery, stripping with acidic recovery and membrane separation. Results showed good performances in terms of nutrients recovery with average yields always over 50% for both nitrogen and phosphorus. The techno-economic assessment showed how the specificity of the monitored systems played a major role: in particular, membranes were able to produce a stream of virtually pure water (up to 50% of the treated digestate) reducing the digestate volume, while drying, because of the limitation on recoverable heat, could treat only a limited portion (lower than 50%) of produced digestate while stripping suffered some problems because of the presence of suspended solids in the liquid fraction treated. Specific capital and operational costs for the three systems were comparable ranging between 5.40 and 6.97 € per m3 of digestate treated and followed the order stripping > drying > membranes. Costs determined in this study were similar to those observed in other European experiences reported in literature
- …
