1,720,954 research outputs found
Interaction between molten blister copper and 316L stainless steel
No full textBlister copper is cast and usually processed further. At the Tsumeb Custom Smelter, Namibia, it is blown with nitrogen from mild steel lances, but these lances do not last long, causing down-time and reduced copper throughput. Additionally, the blister copper purity should be at least 98.5 wt% Cu, else the price is compromised. Thus, keeping contamination to a minimum and reducing down-time are very important.
It was thought that stainless steel lances might last longer than those of mild steel, and since this could not be attempted at the smelter, a simple experiment was undertaken to identify any reactions between the molten copper and the stainless steel. The action of the lance was simulated by using agitation by nitrogen, and the molten copper was poured into stainless steel crucibles, rather than manufacturing lances.
XRF measurements were done on a wave length dispersive Philips PW2404.
Blister copper was melted at 1200C in 316L stainless steel crucibles held at different times under the following conditions: in inert conditions without agitation, in inert conditions with agitation by nitrogen (600kPa pressure and 10 L.min-1 flow-rate), and in oxidizing conditions (500kPa and 21 min-1) with nitrogen agitation. Coke was placed on top of the melt to prevent oxidation. After the specified times, the copper was poured out. Sections were cut through the crucibles and copper remnants, prepared metallographically, and studied using SEM with EDX. Spot analyses were taken across the interface from the blister copper matrix to the steel. X-ray maps were also undertaken across the interface.
For 40 minutes in inert conditions without agitation, the interface was up to ~80m wide. It comprised different discrete phases in the copper-rich matrix. Further from the steel was a very light two-phase mixture: overall: ~86 Cu, ~2 Fe, ~10 C with less than 1 Cr and Ni (wt%), deduced as (Cu) + graphite. Nearer the steel was a darker phase, ~67 Cu, ~20 Fe, ~7 C, ~3 Cr and less that 1 Ni (wt%), deduced as (Fe). The matrix had only ~85 wt% Cu.
After 80 minutes in the same conditions, some of the copper had diffused along the grain
boundaries of the steel, and the interface was ~150m. The very light phase mixture had
nearly disappeared and there was much more porosity.
Under oxygen, there was much slag, of composition: ~10 Cu, ~44 Fe, ~12 Ni, ~2 Cr and
~27 O (wt%), with the copper only having ~96 wt%, purity, i.e. below the accepted limit.
This copper could not be poured freely from the crucible because of the high slag content.
There is a liquid miscibility gap across most of the C-Cu-Fe system, which gave the two
different regions in the interface. There is also a miscibility gap in the fcc solid solution,
which gives the two different phases, (Fe) and (Cu) near the steel.
The 316L stainless steel crucibles contaminated the copper. Under industrial conditions,
and longer times, the effects would be worse, and any 316L lances would deteriorate fast.
Since the liquid miscibility gap occurs very near 100% Cu, it would be better to avoid any
ferrous material, and instead use refractory linings, which are used for the larger vessels,
which would also reduce diffusion
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
No full textWe 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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