1,720,967 research outputs found
Modeling and Simulation of CO2 Capture Process for Coal- based Power Plant Using Amine Solvent in South Korea
No full textAbstractThe interest in carbon capture technology is continuously rising since worldwide climate-change problems have intensified the concern regarding efficient removal of carbon dioxide. Amine-based capture technology is a conventional technology to remove carbon dioxide in natural gas processing, and also can be used for carbon dioxide removal from flue gas in coal-based power plants. In particular, monoethanolamine is a conventional commercial absorbent to remove carbon dioxide and considered as a standard amine absorbent. Due to the high non-ideality of amine, rate-based models have been suggested to describe absorption and desorption of amine absorbent. However, most suggested models were validated against large-scale pilot plant results, and there were few models to consider both absorber and stripper with rate-based model. In this study, we applied two rate-based models introduced by previous literature to the actual pilot plant operation data in 0.1MW-scale Boryeong pilot plant, South Korea and developed a modified model with increased accuracy. The developed model showed good agreements with pilot plant results for both absorber and stripper. However, under low liquid-to-vapor ratio operation with high rich loading value, all model showed worse estimations
Fault diagnosis using the hybrid method of signed digraph and partial least squares with time delay: The pulp mill process
No full textAlthough the existence of a time delay worsens the diagnosis accuracy, most research efforts on fault diagnosis have not considered the time delay. The hybrid fault diagnosis method that is based on the signed digraph (SDG) and the partial least-squares (PLS) has the advantage of improving diagnosis resolution and accuracy, compared to those of previous qualitative methods, and is capable of enhancing the ability to diagnose multiple-fault [Lee et al., Ind. Eng. Chem. Res. 2003, 42, 6145-6154]. The current research modified this method to include the information of the time delay between process variables, and the time delay can be obtained through the open-loop responses of set-point changes. The modified method is applied for the fault diagnosis of the pulp mill process, which produces pulp from wood chips. It is one of the biggest processes in the fault diagnosis area, and it will be a new benchmark process to evaluate the fault diagnosis method. Also, its units, such as the storage tank and the bleaching tower, have a very large time delay. Dynamic principal component analysis (DPCA)-based fault diagnosis was used to get a reference of the diagnosis performance comparison. Although fault detection of the proposed method is frequently slower than DPCA, it gives more accurate results. Also, it demonstrates much-better diagnosis capabilities, compared to the original hybrid method
Energy Saving in Polysilicon Manufacturing Process by using Pinch Technology and Divided Wall Column
No full text학위논문 (석사)-- 서울대학교 대학원 : 화학생물공학부, 2012. 2. Han, Chonghun.Spot market price of polysilicon is in decline; therefore, in order to be competitive, polysilicon manufacturing industry must reduce the manufacturing cost of polysilicon. This can be done by saving energy in the existing plant or developing alternative cost-effective process design. In this work, two techniques have been used to reduce operating and capital costs of the polysilicon manufacturing process: heat integration and complex column structure such as divided wall column. First, process simulation model for polysilicon manufacturing process has been developed. For heat integration, pinch technology has been used to identify pinch rules violations in the current process. An alternative heat-integrated heat exchangers network has been developed which satisfies the pinch rules. Economic analysis results demonstrate that heat-integrated polysilicon manufacturing process can save 255.91 million US capital cost. Moreover, a new methodology for process design and optimization of divided wall column has been proposed. This methodology has been applied to design and optimize a divided wall column (DWC) for silicon tetrachloride (STC) purification. According to results, the DWC for STC purification saves 8 stages, 10.91% reboiler duty and 10.86% condenser duty as compared to the base case of conventional two columns in-series structure for STC purification.Maste
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
Variations 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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
