Morphologie générale de l'articulation du genou

Thèse : Médecine : Université de Bordeaux : 1899N° d'ordre : 7

Diatoms as particulate tracers in the water column in the eastern english channel

International audienc

A differentiation method for separating a mixture of suspended particle size distributions

International audienceA simple method is proposed to partition a mixture of two populations in suspended particle size data. The method, termed here "the differentiation method" is based on the function of the lognormal distribution. Suspended material in marine or estuarine situations often consists of difficult-to-interpret complex populations. The treatment of particle size data by the method described enables the confirmation of the lognormal law and also the demonstration of the occurrence of a combination of a number of populations which may not be distinguished by the classical Gaussian transformation or automatic methods. A simple combination of graphical and numerical techniques permits the decomposition and the easy determination of the various statistical parameters (median diameter, mean diameter, etc...). The method is applied to interpret observed size distributions of suspended particulate matter in the Seine estuary. The method enables the determination of the relative sizes of the constituent sub-populations that comprise the total suspended matter. In the example used to illustrate the method, particles are shown to be resuspended as a function of different hydrodynamic parameter

Continental/marine ratio changes in suspended and settled matter across a macrotidal estuary (the Seine estuary, northwestern France)

International audienc

Role of suspended sediments on the distribution of PCB in the Seine Estuary (France)

International audienc

Chemical characterization of porewaters in an intertidal mudflat of the Seine estuary : relationship to erosion-deposition cycles

International audienc

Hydrodynamics of Suspended Particulate Matter in the Tidal Freshwater Zone of a Macrotidal Estuary (The Seine Estuary, France)

International audienc

Resuspension and advection processes affecting suspended particulate matter concentrations in the central English Channel

Suspended particulate matter (SPM) measurements obtained along a cross-section in the central English Channel (Wight-Cotentin transect) indicate that the area may be differentiated into: (1) an English coastal zone, associated with the highest concentrations; (2) a French coastal zone, with intermediate concentrations; and (3) the offshore waters of the Channel, characterised by a very low suspended-sediment load. The SPM particle-size distribution was modal close to the English coast (main mode 10–12 ?m); the remainder of the area was characterised by flat SPM distributions. Examination of the diatom communities in the SPM suggests that material resuspended in the intertidal zone and the estuarine environments was advected towards the offshore waters of the English Channel.Considerable variations in SPM concentrations occurred during a tidal cycle: maximum concentrations were sometimes up to 3 times higher than the minimum concentrations. Empirical orthogonal function (EOF) analysis of the SPM concentration time series indicates that, although the bottom waters were more turbid than the surficial waters, this was not likely to be the result of in situ sediment resuspension. Instead, the observed variations appear to be controlled mainly by advective mechanisms. The limited resuspension was probably caused by: (1) the limited availability of fine-grained material within the bottom sediments; and (2) ‘bed-armouring’ processes which protect the finer-grained fractions of the seabed material from erosion and entrainment within the overlying flow during the less energetic stages of the tide

Exchange and release processes Dialysis porewater sampler: a strategy for time equilibration optimisation p1-9 in Phosphates in sediments.

International audienc