1,720,962 research outputs found
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
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
Investigations on the temperature dependent performance, degradation, and safety of Li-ion batteries
No full textThe rapid expansion of the use of Li-ion batteries (LIBs) across diverse applications, from portable electronics to battery electric vehicles and large-scale energy storage systems, underscores the need to better understand and to improve their performance, longevity, and safety. An in-depth understanding of LIB degradation processes is essential for developing advanced operating profiles to enlarge their lifetime. This is not only crucial for maximizing sustainability but also for reducing costs simultaneously. Furthermore, ensuring cell safety over the full lifespan even under diverse and extreme operating conditions is critical. This requires a detailed understanding and identification of factors such as deposition of metallic Li that causes rapid battery aging and compromises safety. LIB degradation is driven by numerous factors. They can be grouped into material and design aspects as well as operating and storage conditions. Among these, temperature is one of the most significant influencing factors on LIB degradation. At low temperatures (often < 25 °C), Li plating typically dominates degradation, while at elevated temperatures accelerated parasitic side reactions such as solid-electrolyte-interphase (SEI) growth are dominant. Both mechanisms result in significantly different safety characteristics. Finding the optimal temperature is a trade-off between both aging mechanisms.
This thesis focuses on investigations of temperature dependent aging mechanisms in LIBs using various methods of investigation. Results were reported in the following seven peer-reviewed articles. In the first article, the impact of operating conditions such as temperature, current, and aging state on LIB degradation is examined by using cylindrical 21700-type cells as well as lab-made pouch cells. Arrhenius plots of the cyclic aging rate are used to determine the crossover temperature between Li plating at low temperatures and SEI growth at high temperatures. It is shown that both, aging state and C-rate, shift the crossover temperature. Particularly higher charging C-rates shift the onset of Li plating and thus the crossover temperature towards higher values.
In typical applications, the operating temperature of a battery is not constant but fluctuates in between certain limits. However, most scientific investigations focus on aging processes at one constant temperature only. In the second article, the effect of varying temperatures during cyclic aging is examined. Results reveal that the initial aging temperature can substantially alter subsequent degradation behavior. Especially, aging at high temperatures shifts the onset of Li plating to lower temperatures in subsequent cycles. As a consequence, the optimal aging temperature is reduced and cycle life is extended. Conversely, cycling LIBs under conditions that support Li plating accelerates further Li plating.
The materials choice, particularly on the anode side, further affects the temperature dependent performance. Si-graphite composites are used as anode material in state-of-the-art LIBs. However, Si and graphite have a significantly different electrochemical behavior. The effect of a varying Si content on the temperature dependent performance and degradation is investigated in the third article. A high Si content in the anode is beneficial for a good low temperature performance. However, the high temperature performance is deteriorated by a high Si content due to a strongly increasing cyclic aging rate. Therefore, a balanced Si content in the anode is essential to optimize both, cycle life and performance.
Li deposition in LIBs is problematic, as it correlates with rapid capacity fade and safety concerns. In the fourth article, three workflows addressing whether Li deposition exists in a cell, its location, and the conditions that prevent its formation are presented. Complementary experimental techniques as well as simulation approaches to detect and prevent Li deposition are reviewed. The workflows enable accurate and efficient detection of Li deposition and provide valuable insights for improving battery design, safety, and performance in demanding applications.
Safety of LIBs is significantly influenced by their aging history. In the fifth article, the influence of the dominant aging mechanism and state of health (SOH) on the safety of Li-ion pouch cells is investigated. Accelerating rate calorimetry (ARC) is used to determine safety critical temperatures. In order to gain further insights into thermal decomposition processes and enable early detection of critical events, the ARC method is expanded by multiple low-cost sensors installed on and around the pouch cell. Aging associated with Li plating lowers safety by reducing the onset temperature of self-heating (SH), whereas aging at elevated temperatures raises the onset temperature of SH.
Typically, temperature is measured on the surface of battery cells during operation or safety testing. However, internal temperature can significantly differ from surface temperature. Therefore, a method is presented in the sixth article that uses laser ablation to insert a thermocouple inside a 21700-type cell. ARC experiments of these cells at different state of charge (SOC) provide insights into thermal gradients. The internal temperature changes much faster and to a greater extent than the surface temperature, especially during venting and thermal runaway (TR).
Safety of LIBs is influenced by a number of factors including SOC and aging state. In the seventh article, the safety characteristics of cylindrical 21700-type cells cyclically aged at different temperatures in conjunction with varying SOC are examined by using advanced ARC measurements. The findings indicate that both elevated SOC and cell degradation lower the safety level, both by reducing critical temperatures that necessitate venting and the onset of TR. Furthermore, an increase in destruction level and mass loss of the cell after ARC testing is observed with increasing SOC. Notably, cells exhibiting Li plating show a markedly diminished onset temperature of SH, independent of SOC.
Overall, this work provides for the first time comprehensive insights into temperature dependent LIB degradation, with a particular emphasis on the safety of aged cells. These insights are crucial for a safe and efficient operation and can be used to develop improved next-generation LIBs
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