1,721,398 research outputs found
Il ruolo della meccanizzazione aziendale ed extra-aziendale nel mutamento della risorsa lavoro
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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
Vacuum evaporation treatment of digestate with use of heat from anaerobic digestion
No full textWithin manure management strategies, anaerobic digestion followed by vacuum evaporation of digestate represents an interesting solution for both the reduction of nitrogen and phoshorous surpluses in soils and to avoid odour and gas emissions connected with the operations of treatment and storage of effluents. In reality, both anaerobic digestion and evaporation processes take place in a confined reactor, collecting gaseous emission as biogas and condensate, respectively. The aim of vacuum evaporation is i) to reduce the volume of the slurry to be spread on the field, thus reducing transport and distribution costs, and ii) to produce a condensate that can be discharged, to reduce the storage volume only to the concentrated fraction. Previous anaerobic digestion (AD) provides the heat necessary for the evaporation process, without it wasting in the atmosphere, as usually happens for the amount exceeding the needs of the digestor. With the goal to verify concentration efficiency, energy consumption and characteristics of concentrate and condensate, tests were performed using a one-stage semi-continuous pilot plant fed with the liquid fraction of a cattle slurry and maize silage digestate, without acidification. This practice is used to prevent ammonia volatilisation, but requires significant quantities of acid, thus increasing operational costs and causing problems for the on-farm storage of this product. A 12% TS concentrate was obtained, representing the 40-50% of the effluent. The condensate, because of its ammonia content (2.7 g/L on average) cannot be discharged. A solution for the recovery of ammonia from condensate is the filtration on reverse osmosis (RO) membranes, with previous acidification. Tests are on-going with a RO pilot plant to verify whether discharge limits can be matched. With a heat requirement of 0.87 kWh/kg of condensate, heat is the limiting factor of the process when the objective is to treat the entire quantity of digestate effluent from the biogas plant, especially in winter when the heat demand from AD plant increases
Vacuum evaporation treatment of digestate: Full exploitation of cogeneration heat to process the whole digestate production
No full textVacuum evaporation represents an interesting and innovative solution for managing animal waste surpluses in areas with high livestock density. To reduce operational costs, a key factor is the availability of an inexpensive source of heat, such as that coming from an anaerobic digestion (AD) plant. However, how much of the digestate can be processed with the heat produced by the cogeneration unit? The aim of this study was to test vacuum evaporation for the treatment of cattle slurry digestate focusing on heat exploitation. Tests were performed with a pilot plant evaporator fed with the digestate of a full-scale AD plant. The results were used to evaluate if and how the cogeneration heat can support both the AD plant and the subsequent evaporation of the whole daily digestate production in a full-scale plant. The concentrate obtained (12% total solids) represents 40–50% of the influent. The heat requirement is 0.44 kWh/kg condensate. Heat power availability exceeding the needs of the digestor ranges from 325 (in winter) to 580 kW (in summer) versus the 382 kW required for processing the whole digestate production. To by-pass fluctuations, we propose to use the heat coming from the cogenerator directly in the evaporator, tempering the digestor with the latent heat of distillation vapor
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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