1,720,953 research outputs found
Development of a real-time technique for in-sditu measurement of pH in capacitive deionisation
No full textCapacitive Deionisation (CDI) as a desalination technique proves to be one of the most promising technologies owing to its simplicity and ease of manufacturability. The longevity of CDI depends on a number of factors, such as the ability of carbon to withstand Faradaic reactions to CO2. Furthermore,
like other technologies such as (reverse osmosis) RO and (electrodialysis reversal) EDR, scale formation is known to affect its hydraulic efficiency. The slow mineral deposition of magnesium and calcium carbonate is responsible for such phenomena. The extent of the problem is one where the
hydraulic efficiency of the device drops well below 10%, a state where the device is considered to be at the end-of-life as it is too difficult to pump water through it. In the preliminary study we examined the performance of an industrial scale (membrane capacitive deionisation) MCDI module that has
been in operation intermittently for 5 years to establish familiarity with the performance of a used module.
In the main study, we described a new technique for observing the chemical state within the spacer channel of a CDI cell, the part of the electrode that is prone to blockage. This new technique for the direct measurement of pH is based on colourimetric analysis of a novel synthetic formulation of a
pH-sensitive dye dissolved in the electrolyte phase. The basis for this novel technique combined a simple optical microscope integrated with a microfluidic device. This microfluidic device containing a microreactor cell of 750 picolitres in size was fabricated to host the electrochemical reaction (electrode and electrolyte phases) demonstrated in this study that recreates the “CDI effect” of an industrial cell.
The pH indicator formulations were synthesised from a 1:1:2 ratio of phenolphthalein, bromothymol blue and methyl red in an ethanol solution. The pH indicator, which we denote as the standard formulation (SF), had a density of 0.93 kg/L and pH of 2.74. This was the formulation that was subsequently used in the main part of the study. The dye was characterised by visible range
spectroscopy and subsequent conversion to (hue saturation value) HSV colourmap coordinates using the 1976 CIE (International Commission on Illumination) chromaticity model. This enabled the development of a range of pH-Hue relationships using best approximated by sigmoid functions. In
the analysis of these functions, we investigated the sensitivity of the pH-Hue relationship to variation in the SF formulation due to selective electrosorption of the dye. It was shown that the variation in functions produced was not significant and that the general pH-Hue relationship did not break down
into a non-usable form.
Application of the novel technique was initially performed on a membraneless cell configuration. The pH profile was investigated from a starting range of interest of pH 8 to 9 where scale formation occurs. In the second series of reactions, we demonstrated microreactor CDI configurations with varying degrees of membrane coverage from 12.5% to 100%. It was found that the pH variation in the spacer channel was minimal or non-existent across the full charge cycle from adsorption through to desorption. This indicates that obscuration of the carbon surface blocks the protons diffusing from the surface of the carbon where it is generated by way of the standard faradaic reaction in CDI or blocking co-ions from being expelled from the membrane that may result in speciation that affects the pH.
We recommend longer in-situ observation type studies be performed to confirm the speciation chemistry present in the spacer channel typical of many situations where electrodes are reducing in performance by way of fouling and scale formation
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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