1,720,958 research outputs found
Modélisation de l'hydrologie, des matières en suspension et des flux de carbone organique du bassin du Congo : le rôle de la Cuvette Centrale
No full textThe Congo River basin (CRB) is the second largest drainage basin on Earth after the Amazon in terms of discharge and basin area. It also contains the second largest area of rainforest (1.8 million km2) that also hosts the single largest peatland deposit found (145,500 km2) in the Tropics. The Cuvette Centrale is the quarternary "sag" basin found at the center of this basin that receives flows from all the principal tributaries located in the right bank, left bank and the upper Congo River. While a few studies of the hydrology, sediments and organic matter biogeochemistry of the CRB have been made, there is a need to better constrain the lateral fluxes of material that pass through the Cuvette in order to best understand its role in the basin biogeochemistry at a daily time step. With the aid of the Soil and Water Assessment Tool (SWAT) hydrological model calibrated using scarce data, and validated with remote sensing products, biogeochemical and hydrological models, we have established the role of the Cuvette Centrale as a source of water to the main River during low flow periods for the 2000-2012 simulation period. Furthermore, an analysis of the sediment dynamics in the 2000-2012 period revealed that the Cuvette Centrale is capable of retaining over 23 megatons of material annually produced within the Cuvette Centrale and from upland sources. The models for DOC and POC revealed that hydrology and slope are primary controls on these fluxes. The results revealed that between 1.2 to 1.5 megatons of DOC is produced in the Cuvette Centrale with 0.9 megatons of POC retained in the Cuvette Centrale. At the basin outlet, a flux of 13.4 Mt yr-1 for DOC and 2.2 Mt yr-1 of POC was estimated, consistent with previous estimates.Le bassin du fleuve Congo (BRC) est le deuxième plus grand bassin de drainage sur Terre après l'Amazone en termes de débit et de superficie du bassin. Il contient également la deuxième plus grande zone de forêt tropicale humide (1,8 million km2) qui abrite également le plus grand gisement de tourbières des tropiques (145 500 km2). La Cuvette Centrale est le bassin quarternaire "sag" situé au centre de ce bassin qui reçoit les flux de tous les principaux affluents situés sur la rive droite, la rive gauche et le cours d'eau supérieur du fleuve Congo. Bien que certaines études en l'hydrologie, sur les sédiments et en biogéochimie de la matière organique aient été réalisées sur ce bassin, il est nécessaire de mieux contraindre les flux latéraux de la matière qui passent par la Cuvette afin d'améliorer la compréhension du rôle de la Cuvette dans la biogéochimie du bassin au pas de temps journalier. A l'aide du modèle hydrologique SWAT (Soil and Water Assessment Tool) calibré en utilisant peu de données, et validé avec des produits de télédétection et des modèles biogéochimiques et hydrologiques, nous avons établi que la Cuvette Centrale est une source d'eau pour la cours d'eau principal durant l'étiage de 2000 à 2012. De plus, une analyse de la dynamique sédimentaire sur la période 2000-2012 a révélé que la Cuvette Centrale est capable de retenir plus de 23 mégatonnes de matériaux produits annuellement au sein de la Cuvette Centrale ou provenant de sources situées en amont. Les simulations du COD et du COP ont révélé que l'hydrologie et la pente sont les principaux facteurs de contrôles de ces flux. Les résultats ont révélé qu'entre 1,2 et 1,5 mégatonnes de COD sont produites dans la Cuvette Centrale avec 0,9 mégatonnes de COP retenues dans la Cuvette. À l'exutoire du bassin, des flux de 13,4 Mt an-1 pour le COD et de 2,2 Mt an-1 de COP ont été estimé, ce qui correspond à la gamme d'estimation des précédentes études
Modeling the hydrology, suspended sediments and organic carbon fluxes of the Congo River Basin: the role of the Cuvette Centrale
Get PDFLe bassin du fleuve Congo (BRC) est le deuxième plus grand bassin de drainage sur Terre après l'Amazone en termes de débit et de superficie du bassin. Il contient également la deuxième plus grande zone de forêt tropicale humide (1,8 million km2) qui abrite également le plus grand gisement de tourbières des tropiques (145 500 km2). La Cuvette Centrale est le bassin quarternaire "sag" situé au centre de ce bassin qui reçoit les flux de tous les principaux affluents situés sur la rive droite, la rive gauche et le cours d'eau supérieur du fleuve Congo. Bien que certaines études en l'hydrologie, sur les sédiments et en biogéochimie de la matière organique aient été réalisées sur ce bassin, il est nécessaire de mieux contraindre les flux latéraux de la matière qui passent par la Cuvette afin d'améliorer la compréhension du rôle de la Cuvette dans la biogéochimie du bassin au pas de temps journalier. A l'aide du modèle hydrologique SWAT (Soil and Water Assessment Tool) calibré en utilisant peu de données, et validé avec des produits de télédétection et des modèles biogéochimiques et hydrologiques, nous avons établi que la Cuvette Centrale est une source d'eau pour la cours d'eau principal durant l'étiage de 2000 à 2012. De plus, une analyse de la dynamique sédimentaire sur la période 2000-2012 a révélé que la Cuvette Centrale est capable de retenir plus de 23 mégatonnes de matériaux produits annuellement au sein de la
Cuvette Centrale ou provenant de sources situées en amont. Les simulations du COD et du COP ont révélé que l'hydrologie et la pente sont les principaux facteurs de contrôles de ces flux. Les résultats ont révélé qu'entre 1,2 et 1,5 mégatonnes de COD sont produites dans la Cuvette Centrale avec 0,9 mégatonnes de COP retenues dans la Cuvette. À l'exutoire du bassin, des flux de 13,4 Mt an-1 pour le COD et de 2,2 Mt an-1 de COP ont été estimé, ce qui correspond à la gamme d'estimation des précédentes études.The Congo River basin (CRB) is the second largest drainage basin on Earth after the Amazon in terms of discharge and basin area. It also contains the second largest area of rainforest (1.8 million km2) that also hosts the single largest peatland deposit found (145,500 km2) in the Tropics. The Cuvette Centrale is the quarternary "sag" basin found at the center of this basin that receives flows from all the principal tributaries located in the right bank, left bank and the upper Congo River. While a few studies of the hydrology, sediments and organic matter biogeochemistry of the CRB have been made, there is a need to better constrain the lateral fluxes of material that pass through the Cuvette in order to best understand its role in the basin biogeochemistry at a daily time step. With the aid of the Soil and Water Assessment Tool (SWAT) hydrological model calibrated using scarce data, and validated with remote sensing products, biogeochemical and hydrological models, we
have established the role of the Cuvette Centrale as a source of water to the main River during low flow periods for the 2000-2012 simulation period. Furthermore, an analysis of the sediment dynamics in the 2000-2012 period revealed that the Cuvette Centrale is capable of retaining over 23 megatons of material annually produced within the Cuvette Centrale and from upland sources. The models for DOC and POC revealed that hydrology and slope are primary controls on these fluxes. The results revealed that between 1.2 to 1.5 megatons of DOC is produced in the Cuvette Centrale with 0.9 megatons of POC retained in the Cuvette Centrale. At the basin outlet, a flux of 13.4 Mt yr-1 for DOC and 2.2 Mt yr-1 of POC was estimated, consistent with previous estimates
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
Appropriate 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
- …
