Tailles et poids individuels des principaux taxons du zooplancton lagunaire ivoirien : lagune Ebrié; étangs de pisciculture saumâtres de Layo

Des estimations de poids individuels ont été effectuées pour les principaux taxons de la lagune Ebrié : #Acartia clausi, Pseudodiaptomus hessei, Oithona brevicornis, Moina (cf) micrura, Diaphanosoma (cf.) excisum, Neomysis sp, Brachionus plicatilis. A l'exception des rotifères, des relations longueur-poids ont pu être proposées pour ces espèces. Chez #Acartia on a une relation PS =4,33 Lc1,97 applicable aux stades C1 et C2, et une relation PS = 11,67 Lc3,27applicable aux stades C3 et suivants (Lc en mm et PS en ug). Chez #Pseudodiaptomus les relations correspondantes sont : PS = 10,16 Lc2,02 et PS = 17,72 Lc2,964. Les teneurs en carbone et azote des stades copépodites et adulte d'#A. clausi, l'espèce principale du peuplement, varient peu (47 à 55 % du poids sec pour le C et 13 à 15 % pour le N). L'effet de la fixation au formol, également étudié chez cette espèce, se traduit par une perte en poids sec (26 %) et en carbone (13 %), ainsi que par une diminution du rapport C/N et du coefficient de condition; la longueur n'est pas modifiée. (Résumé d'auteur

Parabolic reciprocity gap for heat source identification

The deformation of solid materials is nearly always accompanied with temperature variations. These variations, governed by the heat diffusion equation stemming from the first and second laws of thermodynamics, are induced by intrinsic dissipation of energy and thermomechanical coupling. Infrared thermography techniques provide an experimental means for measuring thermal fields on specimen boundaries. But even if thermal fields are related to the material behavior they are not intrinsic to it as they also depend on external factors such as boundary conditions. Inverting boundary thermal fields is thus needed to obtain valid insight into the specimen thermomechanical behavior. Such an operation belongs to the class of source inverse problem. Inverse source problems are known to be ill-posed in the sense of Hadamard: their solution does not depend continuously on the data, and is not unique for a general source distribution when using only boundary measurements. Modeling hypotheses on the sought sources are thus needed to properly retrieve information

Identification of transient heat sources using the reciprocity gap

International audienceThe deformation of solid materials is nearly always accompanied with temperature variations, induced by intrinsic dissipation and thermomechanical coupling. Heat sources give precious information on the thermomechanical behavior of materials. They can be indirectly observed from thermal measurements on the specimen boundary, obtained e.g. via infrared thermography. To solve the inverse problem of identifying heat sources from such observations, a non-iterative algebraical method based on the Reciprocity Gap Method is proposed. This approach, used elsewhere mainly for time-independent identification, is applied here to transient measurements. Under appropriate modelling assumptions the number of heat sources, their spatial locations and energies are retrieved, as demonstrated on numerical experiments where the robustness of the method to measurement noise is also studied

Amélioration de l’attractivité et de la compétitivité du territoire wallon pour le secteur des services supérieurs. Étude stratégique exploratoire

Rapport de recherche de l'IWEPS n°1