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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
바인더 디자인을 통한 리튬이온전지 고전압 양극재의 계면 안정화
Get PDF학위논문(박사) -- 서울대학교대학원 : 공과대학 화학생물공학부, 2023. 2. 최장욱.As global warming accelerates in the 21st century, measures to regulate carbon emissions are being actively discussed for sustainable development. In this trend, as the era of full-scale commercialization of electric vehicles begins, lithium-ion batteries (LIBs) and next-generation batteries are receiving tremendous attention. Currently, research is being conducted to increase energy density of the electrode with the goal of improving the mileage, and in the cathode part, high-voltage cathode materials such as layered and spinel structures are considered strong candidates to meet the required demand. However, when the cathode material is driven under a high cut-off voltage condition, the cathode-electrolyte interface (CEI) becomes very unstable, which leads to surface degradation such as electrolyte decomposition. Various attempts have been made to solve this problem, but in this work, the binder, which was mainly considered as an adhesive between the electrode components, was newly provided with the interfacial stabilization function of the high-voltage cathodes through the multifaceted design of the polymer structure and functional groups. The existing commercial PVDF binder has a relatively weak van der Waals interaction with metal oxide of the cathode. Therefore, the binder coverage on the cathode surface is insufficient so that the naïve cathode surface is easily exposed to the electrolyte. However, in this study, we developed a binder capable of inducing good coverage based on strong interactions such as hydrogen bonding and ion-dipole interaction to alleviate various surface degradations and to form a stable CEI.
In chapter 1, spandex (SPDX) as highly elastic binder is applied for nickel-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes in LIBs. The nickel-rich layered NCM811 is predominantly used for LIBs intended for electric vehicles owing to their high specific capacities and minimal use of high-cost cobalt. The intrinsic drawbacks of NCM811 with regard to cycle life and safety have largely been addressed by doping with foreign atoms and by applying surface coating. Here, we report that a highly elastic binder, namely SPDX, can overcome the problems of nickel-rich layered cathode materials and improve their electrochemical properties drastically. The high elasticity of spandex allows it to uniformly coat NCM811 particles via shear force during slurry mixing to protect the particles from undesired interfacial reactions during cycling. The uniform coating of spandex, together with its hydrogen bonding interaction with metal oxide of NCM811, leads to enhanced particle-to-particle interaction, which has multiple advantages, such as high loading capability, superior rate and cycling performance, and low binder content. This study highlights the promise of elastic binders to meet the ever-challenging criteria with respect to nickel-rich cathode materials in cells targeting electric vehicles.
In chapter 2, λ-carrageenan (CRN) as a sacrificial binder is applied for 5 V LiNi0.5Mn1.5O4 (LNMO) cathodes in LIBs. The spinel LNMO is unique among the cathode materials used in LIBs as it can operate at the highest potential (~4.7 V vs. Li/Li+). However, high-voltage operation is a double-edged sword for cathodes: good for high energy density but unfavorable for stable cycling. Specifically, the high-voltage operation in turn decomposes the electrolyte at the CEI, impeding the rate and cycling performance and limiting the widespread industrial adoption of LNMO. This work introduces CRN as a binder for LNMO cathodes to overcome the two challenges these cathodes present during high-voltage operation: cycling stability and high-rate performance. The CRN binder provides good coverage of the LNMO particles via hydrogen and ion-dipole interaction to protect the LNMO surface and thus warrants stable cycling. Moreover, the sulfate group of CRN is decomposed to produce LiSOxF at the CEI, which supports Li-ion conduction and protects the interface from indiscriminate side reactions of the electrolyte to enhance the rate performance. Thus, the CRN binder is sacrificial. The concept of a sacrificial binder could be expanded to other emerging electrodes that are detrimentally affected by the oxidative/reductive decomposition of the electrolyte, highlighting the possibility that binders can play a more active role via their chemical functionality.21세기에 접어들면서 지구온난화가 가속화됨에 따라, 지속 가능한 발전을 위해 탄소 배출에 대한 규제 방안이 활발하게 논의되고 있다. 이에 대한 일환으로 전기자동차의 상용화가 본격적으로 시작되면서 리튬이차전지 및 차세대전지에 대한 관심이 급증하고 있다. 현재, 주행거리 향상을 목표로 전극의 에너지밀도를 증가시키기 위해 연구가 진행되고 있는데, 양극 파트에서는 층상계, 스피넬 구조 등의 고전압 양극재가 요구되는 수요를 충족할 유력한 후보로 여겨진다.
하지만, 해당 양극재를 높은 cut-off voltage 조건에서 구동하면 양극-전해질 계면이 매우 불안정해져 전해질 분해 등의 표면 열화가 발생한다. 이를 해결하기 위한 다양한 시도가 존재하나, 본 연구에서는 주로 전극구성물질 간의 접착제로서의 역할만을 고수해왔던 바인더에 고분자 구조 및 작용기의 다각적 설계를 통해 고전압 양극재의 계면 안정화 기능을 새로이 부여하고자 하였다. 기존 상용화된 PVDF 바인더는 양극재의 metal oxide와는 비교적 약한 van der Waals interaction을 기반으로 결합한다. 따라서, 양극재 표면에 대한 coverage가 부족하여 naïve한 양극재 표면을 전해질에 많이 노출시킨다. 하지만, 본 연구에서는 양극재의 metal oxide와의 hydrogen bonding, ion-dipole interaction 등의 강한 interaction을 기반으로 우수한 coverage를 유도할 수 있는 바인더를 개발하여 각종 표면 부반응을 완화하고 안정적인 CEI를 형성할 수 있도록 시도하였다.Chapter 1. Highly Elastic Binder for LiNi0.8Co0.1Mn0.1O2 Layered Cathodes in Lithium-Ion Batteries 1
1.1 Introduction 1
1.2 Experimental Section 3
1.3 Results and Discussion 6
1.4 Conclusion 15
1.5 Reference 15
Chapter 2. Sacrificial Binder for 5 V LiNi0.5Mn1.5O4 Spinel Cathodes in Lithium-Ion Batteries 37
2.1 Introduction 37
2.2 Experimental Section 40
2.3 Results and Discussion 43
2.4 Conclusion 53
2.5 Reference 53
국문초록 76박
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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