1,720,953 research outputs found
Design of a nozzle test rig
No full textDiese Diplomarbeit setzt sich mit dem Entwurf eines Düsenprüfstandes auseinander. Dazu wird zuerst ein Blick auf bestehende Prüfstände geworfen und deren Aufbau analysiert, um daraus ein Design abzuleiten, welches die gestellten Anforderungen erfüllt. Hauptmotivation dieses Entwurfs ist es eine Prüfstandsumgebung zu schaffen, um einen Prüfling aus dem Forschungsprojekt exFan testen zu können. Dieses Projekt setzt sich mit der Frage auseinander, ob die Abwärme einer Brennstoffzelle eines wasserstoffbetriebenen Flugzeugs dazu genutzt werden kann, zusätzlichen Schub zu erzeugen. Die Abwärme soll mittels Wärmetauscher in den Luftstrom eines Mantelpropellers eingebracht werden und mithilfe des Meredith-Effekts beziehungsweise Junkers Düsenkühlerprinzips zur Schuberzeugung genutzt werden. Um das auf einem Prüfstand zu bewerkstelligen ist ein Luftstrom, welcher durch eine Verdichteranlage bereitgestellt wird, notwendig. Ebenso muss Wärmeenergie bereitgestellt werden, um den Wärmetauscher des Prüflings zu speisen. Des Weiteren muss die übertragene Wärme im Wärmetauscher und der erzeugte Schub des Prüflings genau gemessen werden, um auf den erreichten Effekt schließen zu können. Ein wichtiger Teil dieser Arbeit ist auch die Abschätzung der Prüfstandscharakteristik und die Erstellung von Kennfeldern, welche einen möglichen Betriebsbereich prognostizieren. Ebenso wird eine konkrete Konstruktion ausgeführt und mittels technischer Dokumentation und Zeichnungen festgehalten.This diploma thesis deals with the design of a nozzle test bench. To this purpose, existing test benches are first examined and their structure analysed in order to derive a design that meets the specified requirements. The main motivation for this design is to create a test bench environment in order to test a specimen from the exFan research project. This project deals with the question of whether the waste heat from a fuel cell in a hydrogen-powered aircraft can be used to generate additional thrust. The waste heat is to be introduced into the air flow of the ducted fan by means of a heat exchanger and used to generate thrust with the help of the Meredith effect or Junkers jet cooler principle. Therefore, it is necessary to provide an airflow by a compressor system, also to supply thermal energy to feed the test specimen's heat exchanger. Also, it is crucial to accurately measure the heat transferred in the heat exchanger and the thrust generated by the test object in order to precisely determine the effect achieved. An important part of this work is also the estimation of the test bench characteristics and the creation of characteristic maps that predict a possible operating range. A concrete design is also carried out and recorded by means of technical documentation and drawings
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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