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Ανάπτυξη καινοτόμων νανοσύνθετων υλικών για την εφαρμογή τους σε ηλεκτροχημικές διεργασίες διαχωρισμού
No full textThe topic of this PhD thesis is the development of novel nanocomposite electrodes and ion exchange membranes with the combined use of carbon nanostructures and conductive polymers for their application in an innovative electrochemical desalination technique, i.e., membrane capacitive deionization (MCDI). The nanocomposite electrodes and ion exchange membranes are compared, in terms of their adsorption capacity, with commercial membranes with the aim of increasing the salt adsorption rate and reducing the energy consumption of the desalination system. To this direction, optimization is carried out allowing the MCDI desalination system to be scaled up and increase the capacity. Briefly, the objectives of this thesis are 1) the synthesis of highly conductive electrodes from carbon nanostructures and conductive polymers, 2) the synthesis of nanostructured ion exchange membranes, using carbon nanomaterials, directly onto the conductive electrodes, 3) the development of a laboratory-scale electrochemical water treatment process based on MCDI and the experimental investigation for the determination of the critical process parameters and 4) the optimization of the process, the scale-up and the evaluation of the results. In Chapter 1, as an introduction, some of the most commonly used and promising desalination methods are listed. A literature review of CDI theory is presented in Chapter 2, where a detailed review is made to the basic materials used for the development of the capacitive deionization (CDI) electrodes, such as materials based on nanocarbons and polymers used in the synthesis of the electrodes, as well as to the development techniques of the electrodes mentioning the ideal properties which favor electrosorption. In Chapter 3, an introduction to the membranes used in MCDI is given with an emphasis on the materials used to develop composite membranes. The architecture of CDI electrochemical cells as well as the applications of CDI are presented in Chapter 4. Chapter 5 highlights the market interest with extensive reference to patents around CDI technology. Finally, an evaluation of the cost of the CDI technique and the (positive) environmental impact of this technology is presented. The experimental part of the thesis starts with Chapter 6 where the synthesis of the first active layer of the electrodes on a selected graphite substrate to increase the conductivity using activated carbon is presented, as well as the experiments carried out to compare the MCDI and CDI technology (with and without commercially available membranes, respectively). Subsequently, in Chapter 7, the synthesis of ion exchange membranes based on polyvinyl alcohol (PVA) is presented. The optimization of ion exchange membranes based on PVA and the use of nanocarbons is presented in Chapter 8. In Chapter 9, the nanocarbon-based electrodes are further enhanced with a conductive polymer, Polyaniline (PANI), to reduce the energy consumption of the process. Chapter 10 presents the scale-up of the MCDI system using the optimized conductive electrodes integrated with the composite ion exchange membranes in an arrangement consisting of four electrochemical cells with different connections (in series or parallel). The results are presented in comparison with those obtained using commercially available membranes in the MCDI process to evaluate the produced materials and their application for water treatment (deionization). Finally, Chapter 11 summarizes the conclusions and suggests possible topics for future research.Το θέμα της παρούσας διδακτορικής διατριβής είναι η ανάπτυξη καινοτόμων νανοσύνθετων ηλεκτροδίων και μεμβρανών εναλλαγής ιόντων με τη συνδυαστική χρήση νανοδομών άνθρακα και αγώγιμων πολυμερών για την εφαρμογή τους σε μια καινοτόμα τεχνική αφαλάτωσης ηλεκτροχημικής φύσεως, τον χωρητικό απιονισμό με μεμβράνες (membrane capacitive deionization – MCDI). Τα νανοσύνθετα ηλεκτρόδια και οι μεμβράνες εναλλαγής ιόντων συγκρίνονται, ως προς την προσροφητική τους ικανότητα τους, με μεμβράνες του εμπορίου με στόχο την αύξηση του ρυθμού προσρόφησης άλατος και την μείωση της κατανάλωσης ενέργειας του συστήματος αφαλάτωσης. Προς την κατεύθυνση αυτή, πραγματοποιείται βελτιστοποίηση επιτρέποντας έτσι την ανακλιμάκωση του συστήματος αφαλάτωσης MCDI για τη διαχείριση μεγαλύτερου όγκου δείγματος. Συνοπτικά, η παρούσα διδακτορική διατριβή στοχεύει 1) στη σύνθεση αγώγιμων ηλεκτροδίων από νανοδομές άνθρακα και αγώγιμα πολυμερή, 2) στη σύνθεση νανοσύνθετων μεμβρανών εναλλαγής ιόντων με χρήση νανοϋλικών άνθρακα απευθείας πάνω στα αγώγιμα ηλεκτρόδια, 3) στην ανάπτυξη και πειραματική διερεύνηση εργαστηριακής κλίμακας ηλεκτροχημικής επεξεργασίας νερού με βάση τη διεργασία του MCDI για τον προσδιορισμό των κρίσιμων παραμέτρων και 4) στη βελτιστοποίηση της διεργασίας, την ανακλιμάκωση της και την αξιολόγηση των αποτελεσμάτων. Στο Κεφάλαιο 1, ως εισαγωγή, αναφέρονται μερικές από τις πιο συχνά χρησιμοποιούμενες και πολλά υποσχόμενες μέθοδοι αφαλάτωσης. Μια βιβλιογραφική ανασκόπηση της θεωρίας του CDI παρουσιάζεται στο Κεφάλαιο 2, όπου γίνεται λεπτομερής αναφορά στα βασικά υλικά που χρησιμοποιούνται για την ανάπτυξη των ηλεκτροδίων του χωρητικού απιονισμού (capacitive deionization – CDI), όπως υλικά με βάση τους νανοάνθρακες και πολυμερή που χρησιμοποιούνται στη σύνθεση των ηλεκτροδίων, καθώς και στις τεχνικές ανάπτυξης των ηλεκτροδίων αναφέροντας τις ιδανικές ιδιότητες που ευνοούν την ηλεκτρορόφηση. Στο Κεφάλαιο 3, γίνεται μια εισαγωγή στις μεμβράνες που χρησιμοποιούνται στο MCDI με έμφαση στα υλικά που χρησιμοποιούνται για την ανάπτυξη σύνθετων μεμβρανών. Η αρχιτεκτονική των ηλεκτροχημικών κελιών CDI καθώς και οι εφαρμογές του CDI παρουσιάζονται στο Κεφάλαιο 4. Στο Κεφάλαιο 5 δίνεται έμφαση στο ενδιαφέρον που υπάρχει στην αγορά με εκτενή αναφορά στα διπλώματα ευρεσιτεχνίας γύρω από το CDI. Τέλος, παρουσιάζεται μια αξιολόγηση του κόστους της τεχνικής CDI και των (θετικών) περιβαλλοντικών επιπτώσεων αυτής της τεχνολογίας. Το πειραματικό μέρος της διατριβής, αρχίζει στο Κεφάλαιο 6 όπου παρουσιάζεται η σύνθεση του πρώτου ενεργού στρώματος των ηλεκτροδίων πάνω σε επιλεγμένο υπόστρωμα γραφίτη για την αύξηση της αγωγιμότητας με τη χρήση ενεργού άνθρακα, καθώς και τα πειράματα που πραγματοποιήθηκαν για τη σύγκριση της τεχνολογίας MCDI και CDI (με και χωρίς εμπορικά διαθέσιμες μεμβράνες, αντίστοιχα). Στη συνέχεια, στο Κεφάλαιο 7 παρουσιάζεται η σύνθεση μεμβρανών εναλλαγής ιόντων με βάση την πολυβινυλική αλκοόλη (polyvinyl alcohol – PVA). Η βελτιστοποίηση των μεμβρανών εναλλαγής ιόντων με βάση το PVA και τη χρήση νανοανθράκων παρουσιάζεται στο Κεφάλαιο 8. Στο Κεφάλαιο 9, τα ηλεκτρόδια με βάση τους νανοάνθρακες ενισχύονται περαιτέρω με ένα αγώγιμο πολυμερές, την πολυανιλίνη (Polyaniline – PANI), για τη μείωση της κατανάλωσης ενέργειας της διεργασίας. Στο Κεφάλαιο 10 παρουσιάζεται η ανακλιμάκωση του συστήματος MCDI χρησιμοποιώντας τα βελτιστοποιημένα αγώγιμα ηλεκτρόδια με ενσωματωμένες τις σύνθετες μεμβράνες ιοντοεναλλαγής σε διάταξη που αποτελείται από τέσσερα ηλεκτροχημικά κελία με διαφορετική συνδεσμολογία (σε σειρά ή παράλληλη). Τα αποτελέσματα παρουσιάζονται συγκριτικά με αυτά που προκύπτουν με τη χρήση εμπορικά διαθέσιμων μεμβρανών στη διεργασία MCDI για την αξιολόγηση των παραγόμενων υλικών και την εφαρμογή τους για την επεξεργασία νερού (απιονισμό). Τέλος, στο Κεφάλαιο 11 συνοψίζονται τα συμπεράσματα και προτείνονται πιθανά θέματα για μελλοντική διερεύνηση
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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