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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
Carbothermal reduction of pure metal oxides and ores by the using of microwave energy
No full textThe current Phd thesis investigates the use of microwave radiation as an energy source in the carbothermal reduction of pure metal oxides, ores and metallurgical byproducts. In particular, the reduction of pure copper oxide (CuO), a copper carbonate [Cu2CO3(OH)2] ore, hematitic laterite and red mud is studied. In each case the conditions under which the reduction takes place (temperature, heating rate, composition of reduction atmosphere), the reduction degree rate, and the physicochemical characteristics of the reduction products are examined. Good knowledge of the above data is necessary to scale up the reduction process by microwave radiation and utterly to compare the energy consumption to that of conventional heating methods.Initially, the thermal behavior of microwave heating and the reduction degree of pure copper oxide (CuO) and a malachite ore were studied. It was proven that the dielectric permittivities of the materials in relation to the temperature, and particularly the imaginary permittivity ε΄΄(Τ), determine the amount of the absorbed microwave power and subsequently the heating rate and the maximum attained temperature of the sample. The reduction degree rate of CuO was investigated as a function of four factors: (a) the supplied microwave power, (b) the type of the solid reducing agent, (c) the carbon content in the mixture of CuO-reducing agent, and (d) the granulometry of the reducing agent. Complete reduction of 10 g CuO to metallic copper was achieved after 240 s of microwave heating at 800W using lignite as reducing agent and twice the stoichiometric quantity of carbon. In the second part of the thesis the carbothermic reduction of a hematitic nickeliferous laterite from Agios Ioannis open pit at Lokrida, Greece, is studied. X ray diffraction and Mössbauer phasmatoscopy of the reduced samples, showed the quick reduction of hematite mainly to metallic iron (Fe-Ni) and secondarily to Fe+2 phases, such as spinel, fayalite and ferrosilite. The reduction degree of the laterite ore was examined as a function of the heating duration, the supplied power, the sample mass and the excess of carbon. The optimum reduction conditions in case of a 10 g laterite sample required twice the stoichiometric amount of carbon and a forward power of 800 W, implying maximum temperatures. The third part of the thesis presents the microwave reduction (reductive roasting) of red mud, which is the main metallurgical byproduct of the aluminum industry. The experimental process included the reductive roasting of red mud by using lignite as a reducing agent, followed by the wet magnetic separation of the reduced samples aiming at the production of a metallic iron rich concentrate that potentially could be used in the cast iron industry. The optimum magnetic concentrate that was produced contained 35.15% w/w iron, presenting a 69.3% metallization degree. The initial sample of the red mud, as well as the magnetic and non magnetic samples that were produced by the reductive roasting and the magnetic separation processes, were radiologically analyzed. The presence of the of natural occurring radionuclides 226Ra, 228Ra, 238U, 228Th, 232Th and 40K in concentrations below 1000 Bq.kg has been detected. However, the total concentration of the radionuclides in the magnetic concentrate is equal to 1631 Bq.kg, exceeding the limit of 1000 Bq.kg. The final part of the thesis attempts to theoretically analyze the phenomenon of heating a hematitic bearing laterite ore in a microwave oven by using MathCad v.11 software.. The effect of the amount of the provided power by the microwave source as well as the sample mass, granulometry and shape on the heating rate have been thoroughly examined. It was calculated that, in case of the microwave oven which was used in the experimental work of the thesis, the temperature in the core of a 100 g laterite sample reaches 1000 oC after 180 s of heating, while the absorbed power per mass of the sample equals to 6.25 W/g.Σκοπός της παρούσας διατριβής είναι η συμβολή στην εμβάθυνση της διερεύνησης χρήσης της μικροκυματικής ακτινοβολίας, ως πηγή ενέργειας, στην ανθρακοθερμική αναγωγή καθαρών οξειδίων των μετάλλων, μεταλλευμάτων καθώς και μεταλλουργικών καταλοίπων. Συγκεκριμένα εξετάζεται η αναγωγή: καθαρού οξειδίου του χαλκού (CuO), ενός χαλκούχου ανθρακικού μεταλλεύματος, μεταλλεύματος αιματιτικού λατερίτη και ερυθράς ιλύος. Σε κάθε περίπτωση μελετώνται οι συνθήκες υπό τις οποίες πραγματοποιούνται οι αναγωγικές αντιδράσεις (θερμοκρασία, ρυθμός θέρμανσης, σύσταση αναγωγικής ατμόσφαιρας), ο βαθμός αναγωγής συναρτήσει του χρόνου καθώς και τα φυσικοχημικά χαρακτηριστικά των παραγόμενων προϊόντων.Αρχικά, μελετήθηκε η θερμική συμπεριφορά στη μικροκυματική θέρμανση και η αναγωγή καθαρού οξειδίου του χαλκού (CuO) και ενός χαλκούχου ανθρακικού μεταλλεύματος μαλαχίτη [Cu2CO3(OH)2]. Διαπιστώθηκε ότι οι διηλεκτρικές επιτρεπότητες των υλικών συναρτήσει της θερμοκρασίας, και ιδιαίτερα η φανταστική επιτρεπότητα ε΄΄(Τ), καθορίζουν το ποσό της απορροφώμενης μικροκυματικής ισχύος και συνακόλουθα το ρυθμό θέρμανσης και τη μέγιστη θερμοκρασία που επιτυγχάνεται. Οι διηλεκτρικές ιδιότητες μετρήθηκαν με τη μέθοδο διαταραχής κοιλότητας (cavity perturbation method). Ο ρυθμός αναγωγής του CuO εξετάστηκε συναρτήσει τεσσάρων παραγόντων: (α) της παρεχόμενης μικροκυματικής ισχύος, (β) του είδους του στερεού αναγωγικού μέσου, (γ) της περιεκτικότητας του συμπυκνώματος CuO-αναγωγικού μέσου σε άνθρακα, και (δ) της κοκκομετρίας του αναγωγικού μέσου. Διαπιστώθηκε ότι πλήρης αναγωγή CuO μάζας 10 g προς μεταλλικό χαλκό επιτυγχάνεται ύστερα από 240 s θέρμανσης σε παρεχόμενη ισχύ 800 W, 100% περίσσεια σε άνθρακα και με τη χρήση λιγνίτη ως αναγωγικό μέσο. Στο δεύτερο μέρος της διατριβής μελετήθηκε η αναγωγή ενός μεταλλεύματος αιματιτικού νικελιούχου λατερίτη από το επιφανειακό μεταλλείο του Αγίου Ιωάννη Λοκρίδας. Η χρήση περιθλασιμετρίας ακτίνων Χ και φασματοσκοπίας Mössbauer στα ανηγμένα δείγματα έδειξε τη γρήγορη αναγωγή του αιματίτη κατά κύριο λόγο προς μεταλλικό σίδηρο (Fe-Ni) και δευτερευόντως προς φάσεις δισθενούς σιδήρου όπως σπινέλιους, φαυαλίτη και φεροσσιλίτη. Ο βαθμός αναγωγής του λατερίτη εξετάστηκε συναρτήσει του χρόνου θέρμανσης, της παρεχόμενης ισχύος, της μάζας του δείγματος και της περίσσειας του στερεού άνθρακα. Υπολογίστηκε ότι ο μέγιστος βαθμός αναγωγής για μίγμα μάζας 13.5 g προσεγγίζει το 69% και επιτυγχάνεται ύστερα από 480 s θέρμανσης σε ισχύ 800 W και προσθήκη 100% περίσσειας άνθρακα. Στο τρίτο μέρος της διατριβής μελετήθηκε η αναγωγή (αναγωγική φρύξη) ερυθράς ιλύος, η οποία αποτελεί το κύριο μεταλλουργικό κατάλοιπο της βιομηχανίας αλουμινίου. Η πειραματική διαδικασία που ακολουθήθηκε περιελάβανε την ανθρακοθερμική αναγωγή της ερυθράς ιλύος με χρήση λιγνίτη ως αναγωγικού μέσου ακολουθούμενη από υγρό μαγνητικό διαχωρισμό των ανηγμένων δειγμάτων με σκοπό την παρασκευή ενός πλούσιου σε σίδηρο συμπυκνώματος. Το βέλτιστο συμπύκνωμα που παράχθηκε περιείχε 35.15 % w/w σε σίδηρο με βαθμό μεταλλοποίησης 69.3%. Το αρχικό δείγμα της ερυθράς ιλύος όσο και τα μαγνητικά και μη μαγνητικά κλάσματα που προέκυψαν ύστερα από την αναγωγή και το μαγνητικό διαχωρισμό αναλύθηκαν ως προς τις συγκεντρώσεις των ραδινουκλιδίων τους. Ευρέθηκε η παρουσία των φυσικής προέλευσης ραδιονουκλιδίων: 226Ra, 228Ra, 238U, 228Th, 232Th και 40K σε μερικές συγκεντρώσεις μικρότερες των 1000 Bq.kg. Ωστόσο, η συνολική συγκέντρωση των ραδιονουκλιδίων στο μαγνητικό κλάσμα υπερβαίνει το όριο των 1000 Bq.kg, ισούται με 1631 Bq.kg, που τίθεται για τη χρήση ενός υλικού ως πρώτη ύλη στη βιομηχανία του χυτοσιδήρου. Στο τελευταίο μέρος της διατριβής έγινε προσπάθεια θεωρητικής προσέγγισης του φαινομένου της θέρμανσης μεταλλεύματος αιματιτικού λατερίτη εντός ενός μικροκυματικού φούρνου χρησιμοποιώντας το λογισμικό MathCad 11. Εξετάστηκε η επίδραση που έχουν η παρεχόμενη από την πηγή ισχύς καθώς και η μάζα, η κοκκομετρία και το σχήμα του δείγματος στο ρυθμό θέρμανσης
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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