1,720,954 research outputs found
Investigation of struce and properties of ni-cowb composites produced bu sintering
Full text linkBu çalışmada, farklı bor içeriklerine sahip Ni-Co-W-B metalik cam alaşımlarından sinterleme yöntemiyle Ni-CoWB kompozitleri üretilmiş ve bu kompozitlerin mikroyapısal, mekanik ve kimyasal özellikleri sistematik olarak incelenmiştir. Eriyik döndürme yöntemiyle üretilen amorf şeritler öğütülerek toz formuna dönüştürülmüş ve bu amorf tozlar farklı sıcaklıklarda Spark Plazma Sinterleme (SPS) yöntemiyle sinterlenerek yoğunlaştırılmıştır. Amorf yapıdaki tozların sinterlenmesi sonucu elde edilen kompozitlerde nikel katı çözeltisi ve CoWB fazının birlikte çökelmesiyle gözenek oranı düşük numuneler üretilmiştir. Yoğunluk ölçümleri, her iki kompozitte de yüksek sinterlenebilirlik ve düşük gözenek oranı elde edildiğini göstermiştir. Mikroyapı analizleri sonucunda, Ni??Co??W??B?? ve Ni??Co??W??B?? kompozitlerinde CoWB fazının hacim oranlarının sırasıyla %19 ve %37 olduğu belirlenmiştir. Sertlik değerleri sırasıyla 630 Hv ve 754 Hv olarak ölçülmüş ve her iki kompozit için de kırılma tokluğu değerleri en az 25 MPa·?m bulunmuştur. Aşınma testleri sonucunda her iki kompozitin de yaklaşık 6 ×10-7 mm³/N·m seviyesinde aşınma oranına sahip olduğu belirlenmiştir. Korozyon deneylerinde sinterleme ile üretilen kompozitlerin, ısıl işlemle elde edilen numunelere kıyasla daha düşük direnç gösterdiği, bu sonucun gözeneklerin varlığından kaynaklandığı tespit edilmiştir. Yüksek sıcaklık oksidasyon deneylerinde ise 800 °C ve 900 °C'de elde edilen verilere göre oksidasyon direncinin sermetlerin çoğundan daha iyi olduğu gözlemlenmiş, özellikle Ni??Co??W??B?? kompozitinin oksidasyon direncinin daha yüksek olduğu belirlenmiştir. Sonuç olarak, üretilen Ni-CoWB kompozitlerinin yüksek aşınma direnci, kırılma tokluğu ve oksidasyon dayanımı sayesinde, özellikle yüksek sıcaklıklarda (? 700 °C) aşınma direncinin kritik önem taşıdığı uygulamalarda kullanılabilecek potansiyele sahip olduğu ortaya konmuştur.In this study, Ni–CoWB composites were produced from Ni–Co–W–B metallic-glass alloys with different boron contents by sintering, and the microstructural, mechanical, and chemical properties of these composites were systematically investigated. Amorphous ribbons fabricated by melt spinning were ground into powders, and these amorphous powders were densified at various temperatures by spark plasma sintering (SPS). Sintering of the amorphous powders yielded low-porosity composites through the co-precipitation of a Ni solid solution and the CoWB phase. Density measurements indicated high sinterability and low porosity in both composites. Microstructural analyses revealed CoWB volume fractions of 19% and 37% for the Ni51Co18 W18B13 and Ni37Co22W22B19 compositions, respectively. Vickers hardness values were measured as 630 HV and 754 HV, and the fracture toughness for both composites was at least 25 MPa·?m. Wear tests showed wear rates on the order of 6 × 10-7 mm³/N·m for both materials. Corrosion experiments demonstrated that the sintered composites exhibited lower resistance than heat-treated samples, which was attributed to residual porosity. High-temperature oxidation experiments at 800 °C and 900 °C indicated oxidation resistance superior to that of most cermets, with the Ni37Co22W22B19 composite in particular exhibiting higher resistance. In conclusion, the Ni–CoWB composites produced here combine high wear resistance, robust fracture toughness, and strong oxidation resistance, highlighting their potential for applications where wear resistance at elevated temperatures (? 700 °C) is critically important
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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