1,721,425 research outputs found

    Hazard and persistence evaluation of Acid Mine Drainage (AMD) process in Valle Giove mining area (Rio Marina district, Elba Island)

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    Elba island mining activity has been documented since Roman times and was related mainly to iron exploration and exploitation in three districts: Rio Marina, Rio Albano and Capoliveri. Valle Giove is the greatest open pit of the Rio Marina district with 0.5 km2 and is characterized by a hematite + pyrite ± magnetite ± sphalerite ± chalcopyrite ± galena ± bismuthinite ± anglesite ± cerussite ± native sulfur ore association (Tanelli et al., 2001) occurring in strata, lens or vein deposits (Zuffardi, 1990). The effect of open pit mining and other mining-related activities is that sulfides previously isolated from the atmosphere are exposed to oxygen. The oxidation of sulfides acidifies flowing waters that leach ore minerals and dissolve elements such as arsenic, copper, lead, manganese, iron and zinc (Blowes et al., 2003). All these steps, leading to environmental pollution, are known as Acid Mine Drainage (AMD). At Valle Giove AMD process occurs as testified by all the sampled waters (Giove stream, drainage channels, surficial pools and settling basin) which have pH values ranging from 2.08 to 3.35 and an heavy metals content that reaches 903.16 mg/l for Fe, 45.02 mg/l for Mn, 10.08 mg/l for Zn and 1.75 mg/l for Cu. For a preliminary AMD hazard evaluation a central aligned 100 m mesh square grid sampling (EPA, 2002) was performed and fifty-four different terrain samples (residual soils, waste rocks or debris materials) were collected. They were analysed for major elements by XRF and for trace elements by ICP-AES. Net Acid Producing Potential (NAPP) of terrains was determined following AMIRA procedure (IWRI & EGI, 2002). In addition, spatial distribution of heavy metals and hazard assessment of AMD process were investigated using statistical and geostatistical techniques. Moreover, 3-D Digital Terrain Model (DTM) of the mining area at the beginning (1954) and close to the end (1979) of exploitation were developed using AutoCAD 2004 and SURFER 8 software. The comparison between the two periods shows the distribution of topographical positive (mining waste disposals) and negative variations (quarrying areas) and leads to estimate the volume of the material removed from the mining area in the order of 1.38*106 m3 and the volume of material discharged in the same area in the order of 1.57*103 m3. The latter value must be adjusted with additional investigations since the first-mined open pits next to Valle Giove were used as mine waste dumps (Servida et al., in progress). According to the obtained data three main hazard classes were established and their distribution in the mining area was assessed. About 46% of the mining area surface belongs to class I, where AMD process occurs (NAPP>0 and heavy metals content exceeds law limits), about 52% belongs to class II, where AMD process could occur only if some conditions are satisfied (NAPP>0 and heavy metals content is lower than law limits or NAPP<0 and heavy metals content exceeds law limits), only 2% belongs to class III, where AMD process cannot occurs (NAPP<0 and heavy metals content under law limits). Finally, the persistence of AMD process at Valle Giove was evaluated starting from yearly rainfall, mining waters pH and NAPP values. A complete leaching of the first 0.25 m of the terrains can retain the current environmental conditions for several centuries

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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 Under Sail The Imagination of Jack London, 1893-1902

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    In 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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