1,720,953 research outputs found
Optimising Bioremediation to Enhance Treatment Efficiency in Novel Lightweight Media Mixes
No full textUrbanisation has directly impacted the hydrosphere and water resources, causing degradation of water quality and water flow into streams. Pollutants such as heavy metals, sediments and polyaromatic hydrocarbons (PAHs) are key contaminants of urban stormwater, affecting water quality and the aquatic ecosystem. Traditional technologies focussing on contaminant removals, such as ion exchange and reverse osmosis, are either too complicated or costly. More recent approaches involving low-impact designs (LIDs), such as green roofs and conventional raingardens, have shown promise; however, high installation costs have prevented their more comprehensive implementation.
This study proposes suspended raingardens as a plausible, viable option for sustainable stormwater management in urban settings. Suspended raingardens are an engineered system, which includes natural processes that can assist in the removal of stormwater pollutants without using urban space. These systems can be installed as lightweight filtration units that can be suspended under bridges and on the top of existing structures. This study tested three different novel, lightweight media mixes composed of different proportions of compost, coconut coir (CC), activated carbon (AC), vermiculite, perlite and zeolite against compost (only) control.
The current study focused on identifying microbial communities in the above-mentioned three lightweight media mixes intended for suspended raingardens, with a specific focus on managing PAHs, nutrients, solids and metals in stormwater. Naphthalene, phenanthrene and pyrene were introduced to the media mixes, which were regularly dosed with synthetic stormwater (containing nutrients – phosphate and nitrate) for 9 weeks. Media and effluent samples were analysed for PAHs, nutrients and solids. Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria and fungi were assessed by culture and 16 S rRNA gene and ITS2 region sequencing. The degradation of phenanthrene in the presence of a combination of heavy metals (copper [Cu], zinc [Zn] and lead [Pb]) dosed through synthetic stormwater was also monitored to determine the effect of heavy metals on phenanthrene metabolism.
Results suggest that all three media mixes performed better than compost in removing stormwater pollutants. The maximum reduction of total dissolved solids and nitrates was 68% and 65 %, respectively, compared to 36% solids removal and nitrate leaching achieved with the compost control. The mixes' non-soil components showed low water-holding capacity, with
better microbial activity, whereas the media dominated by compost yielded higher water-holding capacity. PAHs introduced into the media mixes were significantly degraded within 68 days. The percentage of phenanthrene degradation ranged from 91% – 98% and was >95% for pyrene. Degradation of naphthalene for media 2 (compost, CC, AC, zeolite) and 3 (compost, CC, AC, zeolite, perlite, vermiculite) ranged from 89% – 95%. Media 1 (compost, CC, perlite, vermiculite) showed complete naphthalene degradation within 30 days and naphthalene formation as a by-product by 68 days. Plate counts showed high but variable microbial activity between different media. Sequencing demonstrated that media mixes support the growth of potential hydrocarbon (HC)-degrading bacterial and fungal communities, which showed negative correlations to HC levels in the media. These results support our hypothesis that microbial activity has a role in PAH degradation in suspended raingarden media. Furthermore, phenanthrene degradation in media 3 in the presence of Cu, Zn and Pb introduced through stormwater suggest that Cu alone positively affects PAH degradation. At the same time, Pb and its combinations (CuPb, ZnPb) inhibit phenanthrene degradation. Zn alone or in combination (CuZnPb, CuZn) had little to no effect on phenanthrene degradation.
This study also analysed the importance of AC, a media mix component, as a site for potential microbial degradation of phenanthrene and regeneration of further sites for binding. We analysed AC test media mixes with a sterile AC control. The results showed complete degradation of phenanthrene in the tests compared to only 40% removal in the sterile AC media. The AC test media also performed better than media 3. Scanning electron microscopy, adsorption kinetics and adsorption isotherms further supported our hypothesis that AC can be a potential microbial degradation site for phenanthrene, and microbial population on the surface of AC may help regenerate adsorption sites. In summary, this study offered an insight into PAHs’ biodegradation potentials of lightweight media mixes suitable for use in suspended raingardens
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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