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    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Role of solvent in enhancing the production of butyl levulinate from fructose

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    The use of alkyl levulinates is growing interest in fuels. Adding n-butyl levulinate (BL) to fuels presents some benefits compared to ethyl levulinate. The conventional production route of BL is from the esterification of levulinic acid, but the latter compound presents some corrosion issues. Alcoholysis of fructose by butanol over cation exchange resins (solid catalyst) seems to be a better alternative. The effect of water addition, solvent, swelling effect (from the cation exchange resin), and fructose solubility at temperatures higher than 25 °C are unclear on this reaction. To understand these effects, the alcoholysis of fructose by butanol at 110 °C in different solvents, e.g., gamma-valerolactone (GVL), were studied in a pressurized autoclave in an inert environment. The dissolution study was conducted in a temperature range of 20–120 °C in different solvents. The concentration profiles of fructose, 5-(hydroxymethyl)furfural (HMF), 5-(butoxymethyl)furfural (BMF) and BL were analyzed in different solvents: butanol/water, butanol, butanol/GVL/water and butanol/GVL. We found that using a butanol/GVL (70/30 wt%) solvent is better from the conversion and dissolution viewpoints

    From biomass-derived fructose to γ-valerolactone: Process design and techno-economic assessment

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    This work proposes a process design and techno-economic assessment for the production of γ-valerolactone from lignocellulosic derived fructose at industrial scale, with the aim of exploring its feasibility, identifying potential obstacles, and suggesting improvements in the context of France. First, the conceptual process design is developed, the process modelled and optimized. Second, different potential scenarios for the energy supply to the process are analyzed by means of a set of economic key performance indicators, aimed at highlighting the best potential profitability scenario for the sustainable exploitation of waste biomass in the context analyzed. The lowest Minimum Selling Price for GVL is obtained at 10 kt/y plant fueled by biomass, i.e. 1.89 €/kg, along with the highest end-of-live revenue, i.e. 113 M€. Finally, a sensitivity and uncertainties analysis, based on Monte Carlo simulations, are carried out on the results in order to test their robustness with respect to key input parameters
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