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Biogeochemische Signaturen in Sedimenten durch Eisen aus Bergbauregionen : am Beispiel der Spree (NO Deutschland)
No full textDuring open-cast lignite mining in Lusatia (NE Germany), iron sulfide minerals associated with lignite, are exposed to air and weather. The weathering products iron (Fe), sulfate and acids subsequently enter the fluvial-lacustrine system Spree and its tributaries.
The aim of this work was to identify and explain the evolving biogeochemical signatures (spatio-temporal patterns) in River Spree. These signatures are significantly influenced by biogeochemical turnover processes triggered by iron input. To identify the signatures, a regional field study was conducted from the inland delta Spreewald to the mouth. This study was followed by two laboratory experiments under controlled redox conditions to investigate the effect of Fe on the long-term binding of phosphorus and the degradation of particulate organic material in the iron-enriched sediments.
Characteristic elements introduced by lignite mining (iron, sulfur, aluminum, cobalt, nickel) and by urban areas (zinc, lead, copper, chromium) could be determined by means of a principal component analysis. Based on these findings, the impact range of the open-cast mining was determined to be at least ~ 90 km downstream of the Spreewald. Within the urban-influenced systems Fürstenwalde and Berlin, the urban signature is more dominant than the mining signature. By means of sequential extractions and XRD analyses of the sediments, iron binding forms and characteristic iron minerals have been additionally identified (e.g., Fe(III) oxyhydroxides, pyrite, vivianite).
Sediment analyses and column experiments have shown that iron increases the phosphorus sorption and decreases the phosphorus release in the sediments of three studied lakes of the fluvial-lacustrine system. However, the application of different phosphorus retention models for Lake Neuendorfer See showed that Fe cannot reduce the eutrophic state of the lakes along the river, since the water retention times are too short and the external phosphorus loads are too high. Additionally, lake sediments with different Fe contents have been incubated with particulate organic material. Higher Fe contents resulted in reduced emissions of the greenhouse gases CO₂ and CH₄, which can be attributed to a reduced degradation of organic matter by Fe. Possible reasons include sorption processes of (dissolved) organic matter onto Fe oxyhydroxides and toxic effects of iron on microorganisms. Nevertheless, Fe (and sulfate) are available as electron acceptors during the decomposition of organic matter in River Spree.
The findings of this work deepen the understanding of the impact of iron from mining on sulfur, phosphorus and carbon turnover processes in fluvial-lacustrine systems. As a consequence of the Fe input from the Lusatian area, the signature will persist for decades in River Spree.Mit der Braunkohle in der Lausitz (NO Deutschland) liegen Eisensulfide vor, die während des Abbaus der Braunkohle durch abgesenktes Grundwasser freigelegt werden und verwittern. Die Witterungsprodukte Eisen (Fe), Sulfat und Säure gelangen nachfolgend in das benachbarte fluvial-lakustrine System der Spree und ihre Zuflüsse.
Im Rahmen der Arbeit wurden biogeochemische Signaturen (raumzeitliche Musterbildungen), in den Sedimenten der Spree identifiziert und erklärt. Diese werden durch biogeochemische Umsetzungsprozesse verursacht, die maßgeblich durch den Eintrag von Eisen gesteuert werden. Die Arbeit besteht aus einer regionalen Freilandstudie vom Spreewald bis zur Mündung zur Untersuchung der Sedimentzusammensetzung und zwei Laborversuchen unter kontrollierten Redoxbedingungen, um die Auswirkung von Fe auf die langfristige Bindung von Phosphor im Sediment sowie den Abbau von partikulärem organischem Material zu untersuchen.
Mittels Hauptkomponentenanalyse konnten neben Fe und Schwefel charakteristische Elemente, eingetragen durch den Tagebau (u.a. Aluminium, Kobalt, Nickel) und durch urbane Gebiete (Zink, Blei, Kupfer, Chrom), definiert werden. Aufgrund dieser Signaturen wurde die Reichweite des Tagebaueinflusses auf mindestens 90 km flussabwärts des Spreewaldes bestimmt, wobei die Bergbausignatur im Fürstenwalder und Berliner Stadtgebiet von der urbanen Signatur abgelöst wird. Mithilfe sequentieller Extraktionen und XRD konnten zusätzlich Eisenbindungsformen und charakteristische Fe-Minerale identifiziert werden (z.B. FeIII oxidhydroxide, Pyrit, Vivianit).
Sedimentuntersuchungen und Säulenversuche haben bestätigt, dass Fe aus dem Tagebau die Phosphor-Sorption in Sedimenten von drei Spree-Seen erhöht und die Rücklösung verringert. Die Anwendung von Phosphor-Retentionsmodellen am Beispiel des Neuendorfer Sees hat allerdings gezeigt, dass Fe den eutrophen Zustand der Seen entlang der Spree nicht verringern kann, da insbesondere die Wasseraufenthaltszeiten zu gering und die externen Phosphor-Frachten zu groß sind. Zudem wurden Spree-Sedimente mit vers. Eisengehalten mit partikulärem organischen Material inkubiert. Die erhöhten Fe-Gehalte führten zu einer reduzierten Produktion der Treibhausgase CO₂ und CH₄, welches auf einen geringeren Abbau von organischem Material durch Fe zurückgeführt wurde. Als Gründe wurden insbesondere Sorptionsprozesse des (gelösten) organischen Materials an Fe-oxidhydroxide und toxische Effekte des Eisens auf Mikroorganismen diskutiert. Dennoch stehen Fe (und Sulfat) als Elektronenakzeptoren während des Abbaus von organischem Material in der Spree zur Verfügung.
Die Erkenntnisse dieser Arbeit vertiefen das Verständnis über die Folgen des eingetragenen Eisens vom Bergbau auf Teilprozesse der biochemischen Kreisläufe von Schwefel, Phosphor und Kohlenstoff in fluvial-lakustrinen Systemen. In der Spree werden die Signaturen infolge des Fe-Eintrags noch mehrere Jahrzehnte erhalten bleiben
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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