1,720,953 research outputs found
Analyses of the use of antimicrobial substances from renewable raw materials in cooling lubricants
Full text linkDer Einsatz von Kühlschmierstoffen in der metallbearbeitenden Fertigungsindustrie dient u. a. der Verminderung der Reibung sowie dem Abführen der Prozesswärme und stellt so einen elementaren Faktor für die Qualität des Werkstücks dar. Vor allem aufgrund ökologischer Vorteile werden dabei zunehmend wasserbasierte Fluide eingesetzt, in welchen Mikroorganismen optimale Lebensbedingungen vorfinden. Mikrobieller Befall von Kühlschmierstoffen kann zu schwerwiegenden Schäden an der Maschine und dem Werkstück führen und auch die Gesundheit des Maschinenpersonals schädigen, weshalb eine Konservierung mit Bioziden unerlässlich ist. Im Zuge der im Jahr 2012 erlassenen Biozid-Verordnung hat sich die Anzahl der für die Produktgruppe 13 „Metallbearbeitungsflüssigkeiten“ zugelassenen Biozide von ursprünglich mehreren 100 Verbindungen auf weniger als 20 Substanzen reduziert. Diese übrig gebliebenen Substanzen sind aufgrund ihrer toxikologischen und ökotoxikologischen Eigenschaften als kritisch zu betrachten und bedürfen zum Schutz der Umwelt einer Ersetzung durch ungefährlichere Alternativen. Auf Basis dieser Problemstellung konnten sieben Gruppen heimischer, naturbasierter und antimikrobiell wirksamer Substanzen anhand von Literaturangaben identifiziert werden. Aus dieser Auswahl erwiesen sich 35 Substanzen aus den Verbindungsklassen der kurzkettigen Diole sowie einigen Vertreter der sekundären Pflanzenstoffe unter Berücksichtigung toxikologischer, physikalischer, chemischer und wirtschaftlicher Faktoren als besonders geeignet. Durch die Anwendung eines mikrobiologischen Vortests konnte für jede dieser Verbindungen die minimale Hemmkonzentration angegeben werden. Nach einer Selektion wurde in weiterführenden Tests ein Konzentrationsbereich für zehn Verbindungen ermittelt, welcher die aerobe mikrobielle Stoffwechselaktivität über einen Messzeitraum von 20 Tagen unterdrückte. Zudem konnte durch die Anwendung von PCR-Tests gezeigt werden, dass die eingesetzten antimikrobiellen Substanzen lediglich eine hemmende Wirkung ausübten und somit als Biostatikum bezeichnet werden können. Alle in den Kühlschmierstoffen eingesetzten Komponenten konnten durch instrumentelle Analyseverfahren quantifiziert werden und die Stabilität zur Funktionserhaltung des KSS während der Praxisversuche sichergestellt werden. Drei neu entwickelte Kühlschmierstoffe erwiesen sich in Versuchen im Praxismaßstab im Vergleich zu einer gebräuchlichen Emulsion als geeignet und zeigten in Bezug auf toxikologische und ökotoxikologische Eigenschaften deutliche Vorteile.The use of cooling lubricants in the metalworking manufacturing industry serves i. a. the reduction of friction and the dissipation of the process heat and thus represents an elementary factor for the quality of the workpiece. Mainly due to ecological advantages, water-based fluids are increasingly used, in which microorganisms find optimal living conditions. Microbial infestation of cooling lubricants can lead to serious damage to the machine and the workpiece and also harm the health of the machine personnel, which is why preservation with biocides is essential. In the course of the Biocide Regulation issued in 2012, the number of biocides approved for product group 13 "metalworking fluids" has been reduced from originally several 100 compounds to fewer than 20 substances. Due to their toxicological and ecotoxicological properties, these remaining substances must be viewed critically and must be replaced by safer alternatives to protect the environment. On the basis of this problem, seven groups of domestic, nature-based and antimicrobially active substances could be identified based on literature references. From this selection, 35 substances from thes classes of short-chain diols and some representatives of secondary phytochemicals proved to be particularly suitable, taking into account toxicological, physical, chemical and economic factors. By using a microbiological pre-test, the minimum inhibitory concentration could be specified for each of these compounds. After a selection, a concentration range for ten compounds was determined in further tests, which suppressed the aerobic microbial metabolic activity over a measurement period of 20 days. In addition, the use of PCR tests showed that the antimicrobial substances used only had an inhibitory effect and can therefore be described as biostatic. All components used in the cooling lubricants could be quantified by instrumental analysis methods and the stability to maintain the function of the cooling lubricant during the practical tests could be ensured. Three newly developed cooling lubricants proved to be suitable in tests on a practical scale compared to a conventional emulsion and showed clear advantages in terms of toxicological and ecotoxicological properties
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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