1,721,237 research outputs found
Copper speciation mapping of organic wastes using XANES imaging
No full textCopper (Cu) is potentially toxic trace elements present in large amounts in organic wastes (OWs) spread on agricultural lands as fertilizer. Cu speciation in OW is a crucial parameter to understand their fate in soil after spreading and to assess the risk associated with agricultural recycling of OW.
To explore the spatial heterogeneity of Cu species at the µm scale from raw OWs up to digestates and composts, we used a laterally resolved synchrotron techniques, the so-called fluorescence-XANES imaging approach.
For each organic wastes, an initial large area survey scan at 15.8 keV has been conducted to identify the area of interest and obtain overall elemental distributions.
Subsequently, a smaller area has been chosen to conduct fluorescence XANES imaging with the XANES stack itself consisting of individual maps at decreasing energies across the Cu K-edge.
These analyses have been conducted for 7 organic wastes:
Urban-3_Raw_OW
Urban-3_Compost
Agri-1_Raw_OW
Agri-1_Digestate
Agri-1_Compost
Central-1_Raw_OW
Central-1_Digestat
Cours n°6 : Évaluation environnementale, 6.1 Risques agro-environnementaux liés aux matières organiques
Full text linkGoing 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
Binding capacities of dissolved organic matter toward copper in the soil-plant systems amended with organic wastes
No full textLa compréhension des déterminants de la biodisponibilité du cuivre (Cu) dans les sols agricoles recevant des apports de produits résiduaires organiques (Pro) est un enjeu écotoxicologique majeur dans l’optique de préserver la fertilité des sols. La spéciation de Cu dans la solution du sol est classiquement considérée en écotoxicologie prédictive comme le principal déterminant chimique de la biodisponibilité de Cu pour les organismes du sol. Étant donné la forte affinité de Cu pour la matière organique dissoute (MOD), la spéciation de Cu dans la solution du sol est fortement conditionnée par la complexation de Cu avec la MOD. Les modèles de spéciation classiquement utilisés en écotoxicologie prédictive tiennent compte de la variabilité de la concentration en MOD mais sont paramétrés par défaut pour ce qui est des propriétés de complexation (densité et affinité des sites) de la MOD. Pourtant, les apports de Pro et les activités racinaires dans la rhizosphère semblent en mesure de modifier à la fois la concentration et les propriétés de complexation de la MOD. Mes travaux se sont donc proposés (i) de mettre en évidence la variabilité des propriétés de complexation de la MOD dans les systèmes sol-plante recevant des apports de Pro et (ii) d’évaluer l’impact de cette variabilité sur la prédiction de la spéciation de Cu en solution.Understanding copper (Cu) bioavailability determinants in agricultural soils amended with organic waste (OW) is a major ecotoxicological issue in order to preserve soil fertility. Copper speciation in soil solution is conventionally considered in predictive ecotoxicology as the main chemical determinant of Cu bioavailability for soil organisms. Considering the high affinity of Cu for dissolved organic matter (DOM), Cu speciation in soil solution is highly influenced by its complexation with DOM. The speciation models conventionally used in predictive ecotoxicology take into account the variability of DOM concentration but are parameterized by default regarding DOM complexing properties (density and site affinity). However, OW inputs and root activities in the rhizosphere appear able to alter both DOM concentration and its complexing properties. My PhD work proposed (i) to demonstrate the variability in DOM complexing properties in soil-plant systems amended with OW and (ii) to evaluate the impact of this variability on Cu speciation prediction in soil solution.A very wide variability in DOM complexing properties was observed between the 55 soils studied. Plants induced strong changes in DOM complexing properties. The contributions of OW to soil induced an almost systematic increase in DOM complexing properties. Besides considering changes in DOM concentration, pH and total Cu concentration in soil solution, the consideration of variability in DOM complexing properties has substantially improved the Cu speciation prediction in soil solution in comparison with WHAM default setting
- …
