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A Novel Approach for the Economic Evaluation of New CO2 Capture Technologies for Power Plants
Get PDFA sequential approach for the economic evaluation of new CO 2 capture technologies for power plants
No full textThis paper describes a simplified method to estimate the cost of CO 2 avoided for a power plant with a novel CO 2 capture system based on only a limited number of fundamental input parameters used to establish basic mass and energy flows for the plant. The cost calculation method follows a sequential approach, estimating first the cost and efficiency penalty impacts of those elements of the plant that are standard and well characterized. We then define the cost gap allowed for the novel elements to break even against a benchmark plant. This method allows one to estimate: (i) the maximum cost reduction potential that a novel CO 2 capture technology can achieve with respect to a benchmark technology, and (ii) target breakeven costs for technology developers in the form of combinations of CAPEX and OPEX for a novel capture technology needed to make the technology competitive with the benchmark system. Case studies are presented applying the proposed method to post-combustion and oxy-combustion capture systems, showing that: (i) a clear relationship exists between the breakeven costs and the efficiency penalty caused by the CO 2 capture process, mainly because of its effect on the specific capital cost (/t CO2 to ∼60 $/t CO2 for efficiency penalties ranging from 2.7% pts to 11% pts, respectively
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Exergetic and Exergoeconomic Analysis of Three Different Technologies for Post-combustion CO2 Capture
Get PDFVariations on the Author
Get PDF“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
Post-combustion CO2 capture from natural gas combined cycles by solvent supported membranes
Get PDFAbstractAmong the CO2 separation technologies, CO2 membranes are currently receiving an increasing interest, largely thanks to the development of solvents such as ionic liquids and deep eutectic solvents, which are suitable for use in solvent supported membrane systems. The aim of this work is to perform a techno-economic analysis of a natural gas-fired combined cycle power plant integrating CO2 membranes. Such a configuration is based on a two-membrane system, the first one separating the CO2 for final sequestration, the second one used to generate a selective CO2-rich flue gas recycle. The techno-economic assessment uses three modelling tools: (i) process modelling of the complete power plant, performed with the in-house GS code and Aspen Plus, (ii) modelling of the membrane, performed with a finite difference method implemented in Matlab and (iii) economic modelling by a bottom-up approach. The final material balances show that using a moderate pressurization of the combined cycle flue gas results in the lowest energy loss and lowest capture cost
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Get PDFWe 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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