1,720,962 research outputs found
New Performance Indicators for Evaluation of Adsorbents Developed for CO2 Capture with PSA Processes
No full textPerformance Indicators for Evaluation of Adsorbents in Pressure Swing Adsorption CO2 Capture Processes
No full text
이산화탄소 포집용 흡착제를 위한 공정단계에서의 평가 방법론 및 파라미터 데이터베이스
No full text학위논문(박사) - 한국과학기술원 : 생명화학공학과, 2020.8,[iv, 110 p. :]This study contributes to the evaluation of capture adsorbents by proposing models, methods, strategies, and tools helping the evaluation for both molecule-level and process-level analysis. For the molecule-level analysis, a new isotherm model is proposed to address the S-shaped isotherm data, which have received increasing attention because of its remarkable potential in capture processes. By generalizing the model and deriving its spreading pressure, this model is improved in aspects of its applicability and computational efficiency. For the process-level evaluation, an ideal pressure swing adsorption (PSA) process is assumed, and the influence of isotherm parameters on the process is derived mathematically, which leads to a shortcut evaluation method. From the derived method, product purity and energy efficiency are analytically formulated. This simple and fast evaluation method enables the comparative evaluation of many sorbents. For its practical use, several strategies are established by categorizing the situations where the adsorbents are employed in the PSA process. These strategies achieve significant improvement in the computational efficiency and stability of this evaluation work. With the molecular simulation results including isotherm data of thousands of adsorbents, an isotherm parameter library is also established. With this library, the method and strategies of this study are combined, and a software is developed with graphical user interface (GUI), which is named general adsorption library and evaluation (GALE). With this software, a variety of adsorbent evaluation with different situations can be carried out, and its results are provided with the sorbent rankings. This software is available on its website.한국과학기술원 :생명화학공학과
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
이산화탄소 포집용 압력 스윙 흡착(PSA)공정에서 사용되는 흡착제의 새로운 평가지표와 평가지표의 간소화공식
No full text학위논문(석사) - 한국과학기술원 : 생명화학공학과, 2016.2
,[ii, 47 p. :]Pressure swing adsorption (PSA) process is one of the candidate processes for capture. The interest has led to the development of various new adsorbents such as modified zeolite materials and metal-organic frame-works (MOFs). The developed adsorbents are evaluated through lab-scale methods based on simple indicators like working capacity and selectivity. However, these indicators do not accurately indicate and adsorbent's per-formance in a PSA process. In this work, we propose new performance indicators that better reflect the actual process-level performance: efficiency and purity. Both indicators are derived for an idealized PSA process with the extended Langmuir isotherm model, which means they serve as limits of the achievable performance of a PSA process with the tested adsorbent. For simple calculation and quick evaluation, the performance indicators are derived as explicit analytical expressions. Because the indicators are derived with the assumptions of an idealized PSA process, their calculations only require isotherm parameters rather than other process parameters, such as heat of adsorption and mass transfer coefficients, which are harder to obtain experimentally. In order to test whether an adsorbent in question can achieve target purity, the upper bound of purity is also derived by assuming an extreme operating condition. Case study involving the evaluation of zeolite 13X, activated carbon, and Cu-BTC is presented to show the use of the new performance indicators, and the results are compared with rigorous simulation results.한국과학기술원 :생명화학공학과
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