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Particulate organic matter in the river Rhine delta: Its role in trace metal scavenging
No full textSummary in DutchApplied SciencesApplied Science
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
Beoordelingssysteem Nieuwe Stoffen. SIMPLERISK, een model voor het schatten van locale concentraties in water en bodem
No full textHet rapport beschrijft het model SIMPLERISK, een eenvoudig multicompartimentaal boxmodel van het zogenaamde "Mackay-type". SIMPLERISK is een op het gebruik als beoordelingsinstrument toegesneden versie van het eerder ontwikkelde spreadsheetmodel SIMPLESAL. De SIMPLERISK-berekening levert drie verschillende soorten resultaten: 1. Stationaire concentraties in het ontvangende aquatische milieu (water, zwevend slib, sediment, aquatische organismen). Bij de concentratieschatting wordt rekening gehouden met de invloed van verdunning, vervluchtiging, sedimentatie/resuspensie en omzetting. 2. Stationaire concentraties in het terrestrische milieu (bovenste bodemlaag en bodemvocht). Hierbij wordt rekening gehouden met de invloed van vervluchtiging, uitspoeling en omzetting. 3. Het lot van de nieuwe stof in het milieu. De berekende fluxen geven aan in welke mate de stof in de nabijheid van de emissiebron in het milieu zal worden afgebroken, in welke mate de stof zich (met lucht, oppervlaktewater of grondwater) zal verspreiden buiten de onmiddellijke omgeving van de bron, en in welke mate de stof zich zal ophopen in bodem en sediment ter plaatse van het emissiepunt. Het rapport geeft een technische uiteenzetting van SIMPLERISK, die voor potentiele gebruikers kan dienen als handleiding.<br
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Get PDFAppropriate 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
Evaluation System for New Chemicals. SIMPLERISK, a model to estimate local concentrations in water and soil
No full textHet rapport beschrijft het model SIMPLERISK, een eenvoudig multicompartimentaal boxmodel van het zogenaamde "Mackay-type". SIMPLERISK is een op het gebruik als beoordelingsinstrument toegesneden versie van het eerder ontwikkelde spreadsheetmodel SIMPLESAL. De SIMPLERISK-berekening levert drie verschillende soorten resultaten: 1. Stationaire concentraties in het ontvangende aquatische milieu (water, zwevend slib, sediment, aquatische organismen). Bij de concentratieschatting wordt rekening gehouden met de invloed van verdunning, vervluchtiging, sedimentatie/resuspensie en omzetting. 2. Stationaire concentraties in het terrestrische milieu (bovenste bodemlaag en bodemvocht). Hierbij wordt rekening gehouden met de invloed van vervluchtiging, uitspoeling en omzetting. 3. Het lot van de nieuwe stof in het milieu. De berekende fluxen geven aan in welke mate de stof in de nabijheid van de emissiebron in het milieu zal worden afgebroken, in welke mate de stof zich (met lucht, oppervlaktewater of grondwater) zal verspreiden buiten de onmiddellijke omgeving van de bron, en in welke mate de stof zich zal ophopen in bodem en sediment ter plaatse van het emissiepunt. Het rapport geeft een technische uiteenzetting van SIMPLERISK, die voor potentiele gebruikers kan dienen als handleiding.DGM/SR /Leeuwen CJ va
Ecotoxicological risk estimation of new chemical compounds in sediments: an exploratory model study
No full textAn exploratory model study has been carried out in order to evaluate the possibility that, upon discharge of WWTP-effluents into surface water, sediment organisms may be exposed to greater risk than water organisms. The sensitivity of the risk quotient PEC/NEC for a number of suppposedly important model variables has been investigated. It is presumed that sediment organisms are at greater risk than water organisms if the concentration of the emitted chemical in pore water is higher than the concentration in surface water. It is concluded that this may occur when: 1. the sediment-water partition coefficient KP(sed) has a smaller value than the suspended particle-water partition coefficient Kp (susp); this may be so: a difference of a factor of 2 seems realistic 2. particulate matter in the WWTP-effluent settles selectively in the vicinity of the emission point ; great uncertainty exists in this respect: in this study 90% selective settling is considered possible. Should all influences operate together in the same direction, then the PEC/NEC for sediment may become up to three orders of magnitude greater than PEC/NEC for water. Such a coincidence is highly unprobable ; 2 to 10 times higher risk for sediment organisms should be taken into account. The most important influences are: - the ratio Kp9susp)/Kp(sed) - the persistence against transport from and transformation in the sediment. In order to assess the possibility of increased risk for sediment organisms critical evaluation of the possibility that one of these variables takes an extreme value is necessary and, in the light of the great uncertainty associated with the risk assessment of new chemicals, presumably also sufficient.DGM/S
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