1,721,098 research outputs found
Non-linear response of soil N2O emissions to nitrogen fertiliser in a cotton-fallow rotation in sub-tropical Australia
Full text linkNitrogen (N) fertiliser is a major source of atmospheric nitrous oxide (N<sub>2</sub>O), and over recent years there has been growing evidence for a non-linear, exponential relationship between N fertiliser application rate and N<sub>2</sub>O emissions. However, there is still a high level of uncertainty around the relationship of N fertiliser rate and N<sub>2</sub>O emissions for many cropping systems. We conducted year-round measurements of N<sub>2</sub>O emission and lint yield in four N-rate treatments (0, 90, 180 and 270 kg N ha<sup>–1</sup>) in a cotton–fallow rotation on a black vertosol in Australia. We observed a non-linear exponential response of N<sub>2</sub>O emissions to increasing N fertiliser rates with cumulative annual N<sub>2</sub>O emissions of 0.55, 0.67, 1.07 and 1.89 kg N ha<sup>–1</sup> for the four respective N fertiliser rates, but no N response to yield occurred above 180 kg N ha<sup>–1</sup>. The annual N<sub>2</sub>O emission factors induced by N fertiliser were 0.13, 0.29 and 0.50% for the 90, 180 and 270 kg N ha<sup>–1</sup> treatments respectively, significantly lower than the IPCC Tier 1 default value of 1.0%. This nonlinear response suggests that an exponential N<sub>2</sub>O emissions model may be more appropriate for estimating emission of N<sub>2</sub>O from soils cultivated to cotton in Australia. It also demonstrates that improved agricultural N-management practices can be adopted in cotton to substantially reduce N<sub>2</sub>O emissions without affecting yield
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
Determining gas sampling timelines for estimating emissions in small chamber incubation experiments
No full textA laboratory experiment was set up in small chambers for monitoring greenhouse gas emissions and determining the most suitable time for sampling. A six-treatment experiment was conducted, including a one week pre-incubation and a week for incubation. Timelines for sampling were 1, 2, 3, 6 and 24 hours after closing the lid of the incubation chambers. Variation in greenhouse gas fluxes was high due to the time of sampling. The rates of gas emissions increased in first three hours and decreased afterward. The rates of greenhouse gas emissions at 3 hours after closing lids was close to the mean for the 24-h period
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
„Täter und Opfer zugleich“ - Eine Forschungsgruppe am Campus Alpin des KIT erarbeitet Konzepte für eine klimafreundliche Landwirtschaft - Campus-Report am 17.08.2021
No full textTäter und Opfer zugleich. So kann man die Rolle der Landwirtschaft im Kontext des Klimawandels beschreiben. Einerseits stammt gut ein Drittel der schädlichen Klimagase weltweit aus der Landwirtschaft, andererseits leidet sie auch unter den Dürren oder Überschwemmungen, die mit der fortschreitenden Erwärmung verbunden sind. Wie könnte eine klimafreundlichere Landwirtschaft aussehen, wenn die Weltbevölkerung weiter wächst? Wie könnte sie sich optimal an die Klimaveränderungen anpassen, ohne dass die Anbauflächen vergrößert werden müssen? Die Forschungsgruppe „smarte Landwirtschaft“ am Campus Alpin des Karlsruher Instituts für Technologie sucht nach Antworten auf diese Fragen
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
„Der Planet könnte auch 10 Milliarden Menschen ernähren“ – KIT-Forschungsprojekt untersucht Einsparpotentiale bei der Stickstoffdüngung - Campus-Report am 21.11.2023
No full textEs ist ein wirkliches Dilemma. Die wachsende Weltbevölkerung kann auf Düngung mit Stickstoff nicht verzichten, wenn sie keine Hungerkrisen riskieren will. Stickstoffdünger aber hat fatale Auswirkungen auf das Grundwasser und ist zudem verantwortlich für Ausdünstungen von Lachgas, das 300-mal schädlicher für das Klima ist als CO2. Ein Forschungsprojekt am Karlsruher Institut für Technologie hat sich deshalb die Frage gestellt, kann unser Planet überhaupt bald 10 Milliarden Menschen ernähren, ohne dass das gesamte Ökosystem zusammenbricht. Das Ergebnis der Studie lässt hoffen: weltweite Hungerkrisen sind auch bei weiter-wachsender Weltbevölkerung nicht unausweichlich. Eine Umverteilung der Stickstoffdüngung aus den intensiv bewirtschafteten Anbaugebieten des industrialisierten Nordens in die mit Dünger unterversorgten Landwirtschaften beispielsweise in Afrika würde sowohl die Umweltschäden reduzieren als auch die weltweiten Erträge steigern
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
- …
