1,720,969 research outputs found
A comparison of anthropogenic and long-term soil erosion on Banks Peninsula in the South Island of New Zealand, using 137Cs <<[hoch 137 Cs]>> and Kawakawa Tephra
No full textDiese Arbeit befasst sich mit der Bewertung des menschlichen Einflusses auf Bodenerosion auf einem Löss-bedeckten Hang am Fuße der Banks Peninsula, auf der Südinsel von Neuseeland. Die Studie wurde dabei auf einen Hangabschnitt beschränkt, auf dem die für konvexe Hänge typischen Kriech-Prozesse vorherrschen, da diese die für die Meßtechniken notwendigen Annahmen befriedigen. Um langfristige (natürliche) und kurzfristige (vom Menschen verursachte) Erosionsraten zu quantifizieren werden verschiedene Tracer im Boden verwendet. Über die Stärke des Bodens oberhalb einer 26.500 Jahre alten Asche-Schichte und die Quantifizierung dieser Asche wird die langfristige Erosionsrate bestimmt; die kurzfrisitge über die Quantifizierung und Verteilung des radioaktiven Elementes 137Cs auf demselben Hang. Ein Steigungs-abhängiges Transportmodell wird parametrisiert, um die lang- und kurzfrisitge Transporteffizienz auszudrücken, bzw. um die unterschiedlichen Transportraten zu vergleichen. Der Transportkoeffizient, K, für die langfrisitge Erosionsrate beträgt ~0,003 m²/yr. Da auf dem betreffenden Hang Erosion nur in sehr geringen Ausmaßen auftritt, kann die Caesium-Technik - aufgrund ihrer zu geringen Auflösung - kein aussagekräftiges Ergebnis liefern.The task of this study is to assess the severity of anthropogenically induced soil erosion on a loess-mantled hillslope on the foothills of Banks Peninsula, in the South Island of New Zealand. The analysis is restricted to a slope segment representative for the soil creep-type processes that dominate on convex soil-mantled hillslopes which satisfy the assumptions of the soil erosion measurement techniques employed. To quantify long-term (natural) and short-term (anthropogenically induced) erosion rates tracers within the soil are used. The thickness of soil above a ca. 26,500 year old tephra and an inventory of the amount of that tephra are used to determine the long-term rate across a convex hillslope, from the interfluve to the midslope. An inventory of bomb-fallout 137Cs is used to determine short-term rates over the same hillslope. A slope dependent transport model is parameterised to encapsulate transport efficiency relevant to the short and long time scales, and the parameters used as a basis for comparing soil erosion rates at different time scales. For the long-term erosion rate, the parameter K, the transport coefficient, is ~ 0.003 m²/yr. For the short-term erosion rate, the 137Cs analysis does not show any significant redistribution pattern. These results suggest that the erosion occurring on the convex upper backslopes on the ridges of Banks Peninsula is so slow that it cannot be determined with the 137Cs technique, as its resolution is too low. Nonetheless, despite the relatively stable conditions on the upper backslopes, erosion is evident at the tunnel-gullies on the lower backslopes requiring future research for its quantification.submitted by Franz Stephan LutterZsfassung in dt. SpracheWien, Univ. für Bodenkultur, Masterarb., 200
Quantifizierung nachhaltiger Ressourcennutzung innerhalb planetarer Grenzen
No full textDie Nutzung natürlicher Ressourcen nimmt in einem nicht gekannten Ausmaß zu. Daher ist es notwendig, ihr Ausmaß und ihre Auswirkungen mit Hilfe von geeigneten Indikatoren zu messen und Grenzwerte für eine nachhaltige Nutzung zu entwickeln. Umfassende Indikatoren, die jene Mengen an Ressourcen quantifizieren können, die für die Herstellung importierter Güter notwendig waren, gewinnen dabei an Relevanz. Vor diesem Hintergrund gibt diese Dissertation Antworten auf die folgenden Forschungsfragen: (1) Wie sind Indikatoren zu entwickeln, die sowohl die direkte (nationale) als auch indirekte (globale) Dimension der Ressourcennutzung einer Volkswirtschaft abbilden können? (2) Wie sollten solche Indikatoren für Rohstoffe und Wasser gestaltet werden? (3) Welche Prinzipien sollen der Eruierung von Zielwerten für eine nachhaltige Wassernutzung zu Grunde gelegt werden? Im ersten Artikel wird eine Analyse existierender Ansätze zur Kalkulation umfassender Indikatoren durchgeführt. Als Schlussfolgerung wird weitergehende Forschung bezüglich einer soliden Datengrundlage und einer breiten Abdeckung von Sektoren und Ländern angeregt. Ebenso bedarf es eines Dialogs aller involvierten Akteure um sicherzustellen, dass Datensammlung und Methodenharmonisierung abgestimmt und effizient umgesetzt werden. Der zweite Artikel bringt die um Wasserdaten erweiterte Input-Output-Analyse zur Anwendung. Es wird gezeigt, dass mit solchen Modellen mit hohem Produkt und räumlichem Detail eine Reihe an relevanten Politikfragen beantwortet werden können. Dafür müssen jedoch vor allem die Verfügbarkeit und Qualität der Wassernutzungsdaten stark verbessert werden. In Artikel 3 werden aufbauend auf existierenden Ansätze sowie einem Expertendialog Prinzipien für die Erarbeitung von Grenzwerten im Bereich Wasser entwickelt. Dazu gehören Aspekte wie der Fokus auf den Konsum sogenannten blauen Wassers auf der Ebene von Flusseinzugsgebieten mit Hilfe von Indikatoren, die auch auf globaler Ebene anwendbar sind.Humanity's appropriation of natural resources is increasing at an unprecedented pace. It is hence imperative to measure resource use and its impacts through appropriate indicators as well as to develop specific thresholds for a sustainable resource. Comprehensive indicators taking into account resources "embodied" in traded goods and services are of increasing relevance. In this context, this dissertation aims at answering three specific research questions: (1) How to develop indicators which allow for covering the direct (national) and indirect (global) dimensions of resource use of an economy? (2) How to design such indicators for raw materials and water use on the economy-wide level? (3) Which principles have to be followed when identifying targets for sustainable water use? The first article applies an extensive review of existing approaches to calculate comprehensive indicators. It concludes that further research is needed on methodological aspects such as a solid database on resource use, a large sector and country coverage as well as a dialogue between involved actors to ensure a harmonised proceeding. The second article applies environmentally extended input-output analysis to the water case and analyses the potentials as well as future research needs of . It is shown that such models with high product and geographical detail can theoretically address a number of policy questions. However, there is a strong need for an improved data basis on water appropriation. Building on existing approaches as well as on an expert dialogue, the third article develops principles to be followed when identifying targets for sustainable water use. These include aspects such as a focus on blue water consumption at the watershed level with indicators that are equally applicable for the global dimension. Hence, this dissertation contributes to the field of target setting in order to achieve the urgently required turnaround towards a sustainable use of natural resources.by Franz Stephan Lutter, MSc, MScAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZusammenfassung in deutscher SpracheDissertation Universität für Bodenkultur Wien 201
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
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