1,721,266 research outputs found
Pedogenesis of Belgian loess-derived soils. Meteoric 10Be inventories derived from authigenic 10Be/9Be ratios
No full textedition: 1status: Publishe
Fe and Zr/Rb XRF data from Black Sea sediment core M72/5-22GC-8 during Termination 2
No full textFe and Zr/Rb records spanning Termination 2 were obtained from Black Sea sediment core M72/5-22GC-8 (803.75 -941.75 cm core depth) at 500 µm resolution using an ITRAX core scanner equipped with a Cr tube at 30 kV, 30 mA and with 15 seconds dwell time in 2020. Sediment core M72/5-22GC-8 was recovered from the south-eastern Black Sea (Archangelsky Ridge, 42°13.5'N, 36°29.6'E, 847 m bsl.) using a gravity corer during RV Meteor cruise M72/5 in 2007. Primary objective of the measurements was to establish time-series of multi-decadal element variability
10Be and 9Be concentrations in Black Sea sediment core M72/5-22GC-8 covering Termination 2 (133.5 - 127.8 ka BP)
No full text10Be and 9Be records spanning Termination 2 (133.5 – 127.8 ka BP) were obtained from freeze-dried and homogenized samples of Black Sea sediment core M72/5-22GC-8 at 0.5 cm resolution. 10Be concentrations were measured using a MILEA accelerator mass spectrometry (AMS) system in 2021. 9Be concentrations analyzed using inductively coupled plasma mass spectrometry (ICP-MS, iCAP Q, Thermo Fisher Scientific) in 2021. Sediment core M72/5-22GC-8 was recovered from the south-eastern Black Sea (Archangelsky Ridge, 42°13.5'N, 36°29.6'E, 847 m bsl.) using a gravity corer during RV Meteor cruise M72/5 in 2007. Primary objective of the measurements was to establish time-series of 10Be and 9Be variability at multi-decadal resolution
Bioavailable actinide fluxes to the Irish Sea from Sellafield-labelled sediments
No full textNuclear discharges to the oceans have given rise to significant accumulations of radionuclides in sediments which can later remobilise back into the water column. A continuing supply of radionuclides to aquatic organisms and the human food chain can therefore exist, despite the absence of ongoing nuclear discharges. Radionuclide remobilisation from sediment is consequently a critical component of the modelled radiation dose to the public. However, radionuclide remobilisation fluxes from contaminated marine sediments have never been quantitatively determined in-situ to provide a valid assessment of the issue. Here, we combine recent advances in the Diffusive Gradients in Thin Films (DGT) sampling technique with ultrasensitive measurement by accelerator mass spectrometry (AMS) to calculate the remobilisation fluxes of plutonium, americium and uranium isotopes from the Esk Estuary sediments (UK), which have accumulated historic discharges from the Sellafield nuclear reprocessing facility. Isotopic evidence indicates the local biota are accumulating remobilised plutonium and demonstrates the DGT technique as a valid bioavailability proxy, which more accurately reflects the elemental fractionation of the actinides in the biota than traditional bulk water sampling. These results provide a fundamental evaluation of the re-incorporation of bioavailable actinides into the biosphere from sediment reservoirs. We therefore anticipate this work will provide a tool and point of reference to improve radiation dose modelling and contribute insight for other environmental projects, such as the near-surface and deep disposal of nuclear waste
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
10Be surface exposure dating of the last deglaciation in the Aare Valley, Switzerland
Full text linkThe combined Rhone and Aare Glaciers presumably reached their last glacial maximum (LGM) extent on the Swiss Plateau prior to 24 ka. Two well-preserved, less extensive moraine stades, the Gurten and Bern Stade, document the last deglaciation of the Aare Valley, yet age constraints are very scarce. In order to establish a more robust chronology for the glacial/deglacial history of the Aare Valley, we applied 10Be surface exposure dating on eleven boulders from the Gurten and Bern Stade. Several exposure ages are of Holocene age and likely document post-depositional processes, including boulder toppling and quarrying. The remaining exposure ages, however yield oldest ages of 20.7 ± 2.2 ka for the Gurten Stade and 19.0 ± 2.0 ka for the Bern Stade. Our results are in good agreement with published chronologies from other sites in the Alps.Fil: Wüthrich, Lorenz. University of Bern; SuizaFil: Garcia Morabito, Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio. Universidad Nacional de Río Negro. Instituto de Investigaciones en Diversidad Cultural y Procesos de Cambio; Argentina. University of Bern; SuizaFil: Zech, Jana. University of Bern; SuizaFil: Trauerstein, Mareike. University of Bern; SuizaFil: Veit, Heinz. University of Bern; SuizaFil: Gnägi, Christian. University of Bern; SuizaFil: Merchel, Silke. Helmholtz-zentrum, Dresden-rossendorf, Deutschland; AlemaniaFil: Scharf, Andreas. Helmholtz-Zentrum; AlemaniaFil: Rugel, Georg. Helmholtz-Zentrum; AlemaniaFil: Christl, Marcus. Eidgenössische Technische Hochschule Zürich; SuizaFil: Zech, Roland. University of Bern; Suiz
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