1,721,037 research outputs found
Thermal Dimensional Stability of Different Low Thermal Expansion Graphite Cast Irons
No full text本研究之內容包含三部分，第一部分係針對具不同石墨型態之低熱膨脹鑄鐵，探討均質化熱處理對於合金元素Ni之偏析程度及基地固溶C量之影響，並進一步探討其對於熱膨脹係數(α值)的影響；第二部分係以拘束型熱循環試驗來分析比較具不同石墨型態之低熱膨脹鑄鐵的尺寸穩定性；第三部分係依據相關力學及熱傳理論，以三維實體模型針對具不同石墨形態之低熱膨脹鑄鐵進行試片經拘束型熱循環試驗後之溫度分佈、熱應力值以及尺寸變化量之模擬分析，並進一步探討α值與熱應力及合金尺寸穩定性之關聯性。 本研究為探討固溶C量與Ni偏析程度對於α值之影響，分別進行了三項迴歸分析；固溶C量對α值、Ni偏析程度對α值以及兩者對於α值之複合影響，分析結果如下: 固溶C量對α值:α=1.06%C+4.6; R2=0.33 Ni偏析程度對α值:α=1.01%Nid+2.81; R2=0.92 固溶C量與Ni偏析程度對α值:α=0.68%C+1.05%Nid+2.41; R2=0.96 由分析結果可知，固溶C量與Ni偏析程度兩個因子會同步影響α值，故欲降低α值，必須同時降低合金之Ni偏析程度及固溶C量，但Ni偏析程度之影響較固溶C量高。 此外，由本研結果究得知，球墨鑄鐵、片墨鑄鐵、縮墨鑄鐵於鑄態時，α值由大至小為球墨>縮墨>片墨；而在施以同樣熱處理條件T1(1150oC/4hr/FC/750oC/4hr/WQ)下，α值為片墨>縮墨>球墨。 另外，針對三爐次(片墨、縮墨、球墨)在經過均質化熱處理後，進行拘束型熱循環疲勞試驗，並量測試片之形狀變化量，並與一般球墨鑄鐵及304不�袗�進行比較。實驗結果顯示，三爐次其形狀變化量皆低於一般球墨鑄鐵以及304不鏽鋼，且合金之尺寸穩定性與α值有明確的相關性，當α值愈小時，所造成之變形量愈小，故尺寸穩定性愈佳，而尺寸穩定性為球墨>縮墨>片墨。The primary purposes of this research are three fold: (1) to investigate the effect of a specific heat treatment (TI: 1150oC-4h/FC/750oC-4h/WQ) on the Ni segregation, C content dissolved in the matrix, and α value in three different graphitic cast irons, (2) to conduct the constrained thermal cyclic tests to evaluate the dimensional stability of the alloys studied, and (3) to employ the finite element method (ANSYS) to simulate the temperature field, thermal stress and shape change of specimens after the thermal cyclic tests, and further to assess the correlation among α value, thermal stress and dimensional stability. Regression analyses were performed to correlate the carbon content dissolved in the matrix and/or degree of Ni segregation with α value, with the results being shown below: (1) α value vs. C content dissolved in the matrix: α = 1.06%C + 4.6; R2 = 0.03 (2) α value vs. Degree of Ni segregation: α = 1.01Nid + 2.81; R2 = 0.92 (3) α value vs. both C content dissolved in the matrix and Degree of Ni segregation: α = 0.68%C + 1.05Nid + 2.41; R2 = 0.96 Based upon the regression analysis results, α value can be decreased by reducing both the carbon content dissolved in the matrix and degree of Ni segregation, with the latter being the dominant factor. Regarding the effect of the graphite type on α value, α value decreases according to the following order: SG > CG > FG, in the as-cast condition. On the other hand, α value decreases according to the following order: CG > FG > SG, in the T1 heat treatment condition. Shape change (△PV) of the specimens after constrained thermal cyclic tests (500 cycles) were measured for low thermal expansion cast irons with different graphite shape (in T1 heat treatment condition) and two other alloys, SUS 304 and regular ductile cast iron. The results indicate that the shape changes in low thermal expansion cast irons regardless of graphite shape are substantially lower than both SUS 304 and regular ductile cast iron. Furthermore, among the low thermal expansion cast irons the shape change or dimensional stability is closely related with α value, that is, the lower the α value, the less the shape change or the better the dimensional stability. Therefore, the order of dimensional stability is SG > CG > FG
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
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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