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Numerical investigation of the use of externally generated Lorentz forces to improve the flow pattern in a continuous glass-melting tank
Get PDFDas elektromagnetische Boosting (EMB) ist ein neuer und innovativer Lösungsansatz zur Verbesserung der Strömungsverhältnisse in den kontinuierlich arbeitenden Glasschmelzwannen mit einer elektrischen Zusatzbeheizung. Das EMB basiert auf der Benutzung von extern induzierten Lorentzkräften, die entgegen der Hauptströmungsrichtung in der Schmelzwanne gerichtet sind. Die Generierung dieser zusätzlichen Lorentzkräfte erfolgt durch die Überlagerung eines externen Magnetfeldes mit der in der Glasschmelze fließenden elektrischen Ströme. Das externe Magnetfeld wird von zusätzlichen Magnetspulen generiert. Diese werden unterhalb des Wannenbodens zwischen den Elektroden der Zusatzbeheizung installiert. Dadurch wird ein steuerbarer elektromagnetischer Wall in der Glasschmelze zwischen den Elektroden realisiert. Dieser verhindert die unerwünschte Strömung der kälteren, bodennahen Glasschmelze zum Wannenauslass. Als Ergebnis wird die minimale Verweilzeit (MRT) der Glasschmelze in der Wanne erhöht und somit die Verweilzeitverteilung (RTD) verbessert. Als Ergebnis wird die Glasqualität erhöht. In dieser Dissertation wird das EMB in einer Glasschmelzwanne numerisch untersucht und somit die Grundlage für eine industrielle Anwendung gelegt. Die stark temperaturabhängigen Materialeigenschaften von Glas erfordern gekoppelte Berechnungen von Elektro-, Thermo- und Hydrodynamik, die zu hochkomplexen, dreidimensionalen, numerischen Simulationen der Problemstellung führen. Die Simulationen werden für eine reale industrielle Glasschmelzwanne unter Annahme einiger Vereinfachungen durchgeführt. Die Randbedingungen sind so definiert, dass die realen Betriebsverhältnisse der Wanne simuliert werden können. Für das EMB wird ein zusätzliches Spulensystem angepasst. Die Simulationen zeigen, dass es im Prinzip möglich ist, einen steuerbaren elektromagnetischen Wall im Boostingbereich zu erzeugen. Um die optimale Wirkung des EMB zu erzielen, sind Parameterstudien durchgeführt worden. Mit diesen Simulationen wird erstmals das dynamische Betriebsverhalten einer Glasschmelzwanne mit EMB untersucht. Die Ergebnisse zeigen, dass die gewünschte wesentliche Erhöhung von MRT und die damit verbundene Verbesserung von RTD mit Hilfe des EMB erzielbar sind, wodurch die Qualität des Endproduktes erhöht wird. Des Weiteren kann mit Hilfe des EMB die Glasqualität verbessert und gleichzeitig der Durchsatz der Wanne erhöht werden. Unter normalen Betriebsverhältnissen ohne das EMB ist dies nicht möglich. Diese theoretischen Untersuchungen bilden den ersten Schritt, das EMB in der Praxis zu testen und einzusetzen, um neuartige Glasschmelzwannen mit höherem Wirkungsgrad und verbesserter Qualität des Glasproduktes in der Industrie einzuführen.Electromagnetic boosting (EMB) is a new and innovative approach for improving the flow patterns within electrically boosted continuous glass-melting tanks. EMB is basically achieved by electromagnetic (Lorentz) forces that are orientated against the main flow direction of the glass melt in the tank. The additional Lorentz forces are produced within the glass melt by an externally generated magnetic field interacting with the electric currents that exist within the glass melt. For the process, additional magnet coils are placed underneath the tank bottom and positioned between heating electrodes. Thus, a controllable electromagnetic wall is created in the boosting area to impede the flow of the colder, less well-melted bottom glass through the gaps between the electrodes towards the tank-outlet. The desired EMB effect is an increase in the minimum residence time (MRT) of the glass melt within the tank and consequent improving of the residence time distribution (RTD), with enhanced glass quality as the ultimate result. Using numerical tools, the author of this thesis has realized and evaluated the EMB in a continuous glass-melting tank, laying the foundation necessary for the idea to be converted into an effective industrial process. As the physical properties of glass are strongly temperature-dependent, the numerical simulation involves calculation of the coupled electrodynamic, thermodynamic, and hydrodynamic effects. The investigation thus largely consists in a highly complex coupled three-dimensional mathematical problem. The simulations are performed for a particular industrial-scale continuous glass-melting tank which is represented in academic form. The boundary conditions are so defined as to simulate the realistic conditions of the particular tank. An external magnet coils system which would produce EMB in the particular tank is incorporated into the calculations. The simulations show that it is basically possible to create an electromagnetic wall within the glass melt between the heating electrodes. Parameter analyses for optimization of the EMB effect are also presented. The simulation results make it possible, for the first time, to analyze the dynamic behavior of an electromagnetically boosted continuous glass-melting tank in operation. They also reveal that EMB affects the glass melt flow within the tank favorably, increasing the MRT substantially and thus enhancing the glass quality. Moreover, the tank simulations with EMB show that it is possible to increase the tank productivity and enhance the glass quality simultaneously, which is not possible in the ordinary tank operation case without EMB. Through the author’s work, the first step, always the most important, has been taken en route to a sophisticated glass-melting tank characterized by high efficiency and high production quality
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
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