1,720,987 research outputs found
Process analysis applied to water reuse for a “closed water cycle” approach
No full textThe reuse of wastewater is a key factor in a closed water cycle approach, in which wastewater is treated
and then reused. This approach is both mandatory for the development of dry areas and necessary for the
sustainability of industrialized countries in terms of environmental impacts and resource preservation.
Although there are some virtuous examples of water reuse projects in the world, there is still much to
be done, especially in terms of incentives and economic viability. Aim of the present paper is to give ther-modynamic and engineering elements in order to develop an economic incentive to promote wastewater
reuse and to adopt the closed water cycle approach. At this scope a techno-economic analysis of the civil
wastewater depuration and reverse osmosis treatment of the secondary effluent is presented, by using
the typical approach of the chemical engineering. The cost of the treated water in relation to the funda-mental parameters of the plant is calculated together with an ‘‘energy based” incentive, evaluated
through the efficiency of the state-of-the-art desalination process. This last can make a reuse project eco-nomically feasible on the basis of rigorous thermodynamic considerations. These latter give a universal
character to the incentive calculation and also reward the process optimization towards the goal of low-ering the carbon emissions. The validity of the proposed method is evaluated through the analysis of
three wastewater treatment and reuse projects at different scale. The results show how it is possible
to obtain a positive Earnings Before Interests and Taxes (EBIT) for plant productivity above the
200 m3/day, by including the proposed incentive in the Business Plan of the integrated plant of Water
Treatment and Reus
Simulation and optimization of an innovative thermochemical water splitting cycle for the production of green hydrogen
No full textHighly efficient and cost-effective green Hydrogen production is a crucial challenge in a future sustainable economy. The innovative Nickel–Iodine-Sulphur (NIS) thermochemical cycle is a potential candidate for this purpose. For the first time in literature, this paper provides a complete Aspen Plus V10 simulation of the closed NIS cycle. Whitin the cycle, the Bunsen reactor was simulated as a PFR with a kinetic constant k = 1.38 m3/mol·s, while the other four reactors were considered at the thermodynamic equilibrium. A simulation of the conventional IS cycle was used as a benchmark for the NIS cycle, whose process parameters were optimized through a sensitivity study. Finally, the thermal efficiency without heat recovery of both cycles was calculated through an energy balance. The simulation results shows that the NIS cycle simulation achieves the same stoichiometric hydrogen yield as the IS cycle and a 17% higher thermal efficiency than the latter
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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