1,720,993 research outputs found
Development of Ni-based catalysts via microemulsion synthesis approach for methane dry reforming / Muhammad Usman Rashid
Get PDFDry reforming of methane has drawn increased attention as it utilizes inexpensive, local source of energy; landfill gas, containing considerable amounts of methane and carbon dioxide produced by anaerobic decomposition of municipal solid waste. In this study, microemulsion synthesis approach was adopted to synthesize Ni-based catalysts supported on MgO and CeO2. The investigation on the various synthesis parameters effecting Ni metal surface area such as: water-to-surfactant ratio (0.33, 0.5 and 0.66), aging time (0.5 to 24 h), calcination temperature (450 to 1000 oC) and Ni metal molar concentration (2 M to 7 M) exhibited that favourable parameters for the achievement of higher Ni surface area are the low calcination temperature (450 oC), moderate aging time (2 h) and lower Ni metal molar concentration (2 M). Furthermore, at constant water-to-surfactant ratio, an increase in water content leads to the decrease in surface area due to the higher micellar exchange rate favouring the growth of larger particles. 20%Ni/MgO catalyst exhibited higher methane (49.93 %) and carbon dioxide (54.80 %) conversion compared to pure Ni particles (18.72% CH4 and 21.80% CO2 conversion). Further study on the influence of calcination temperatures (450 oC, 600 oC and 800 oC) over 20%Ni/MgO catalysts indicated that the increase of calcination temperature (from 450 to 800 oC) leads to the decrease in surface area from 153.22 m2/g to 34.72 m2/g and also exhibits lower stability compared to the catalyst calcined at lower calcination temperature (450 oC). However, when the influence of calcination temperatures (450 oC, 600 oC and 800 oC) on the NiO-MgO solid solution formation was investigated with different Ni metal content (20, 40 and 80 wt%), it was observed that 80%Ni/MgO catalyst calcined at higher temperature (800 oC) exhibited better catalytic activity and stability at a very high weight hourly space velocity (WHSV = 1.68 x 105 ml h-1 g-1). This was attributed to the presence of higher Nio active sites due to higher Ni content and formation of strong NiO-MgO solid solution. The application of higher reduction temperature (800 oC) to 80%Ni/MgO exhibited severe deactivation compared to the catalyst reduced at lower temperature (550 oC). This was attributed to the fact that the catalyst reduced at lower temperature was less prone to sintering. Core-shell like structures (Ni@CeO2) were synthesized at different Ni content (20% Ni, 40% Ni, and 80%Ni) and investigated at reaction temperature of 800 oC and WHSV of 1.2 x 105 ml h-1 g-1. 40% Ni@CeO2 exhibited higher catalytic activity and better stability compared to 20% Ni@CeO2 and 80% Ni@CeO2. This leads to the conclusion that proper balance between Ni active sites and CeO2 content played a critical role in the achievement of higher stability and in the suppression of carbon deposition. Fresh and spent catalysts were characterized by BET, XRD, TPR-H2, TPD-CO2, FESEM and TEM
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
- …
