We present a (partial) historical summary of the mathematical analysis of finite differences and finite volumes methods, paying a special attention to the Lax-Richtmyer and Lax-Wendroff theorems. We then state a Lax-Wendroff consistency result for convection operators on staggered grids (often used in fluid flow simulations), which illustrates a recent generalization of the flux consistency notion designed to cope with general discrete functions.
Helicity plays an important role in spectacular geophysical phenomena such as hurricanes or the generation of the terrestrial magnetic field. The present investigation shows how helicity can be created in a statistically homogeneous but anisotropic flow, driven by buoyancy. If the flow is close enough to a two-dimensional limit, spontaneous symmetry breaking leads to the generation of mean helicity.
The stereocontrol of tertiary alcohols represents a recurrent challenge in organic synthesis. In the present paper, we describe a simple, efficient, and indirect method to enantioselectively prepare tertiary alcohols through a chiral isothiourea catalyzed selective acylation of adjacent secondary alcohols.
Detailed knowledge about hepatitis B virus (HBV) vaccination coverage and timeliness for sub-Saharan Africa is scarce. We used data from a community-based cross-sectional survey conducted in 2018–2019 in the area of Niakhar, Senegal, to estimate coverage, timeliness, and factors associated with non-adherence to the World Health Organisation-recommended vaccination schedules in children born in 2016 (year of the birth dose (BD) introduction in Senegal) and 2017–2018.
Laboratory measurements of light scattered by a cloud of randomly oriented levitating particles are often used to interpret remote sensing measurements of dust in space and in Earth's atmosphere. It is necessary to know how many particles or how many different orientations of the same particles must be considered to retrieve the mean scattering function of brightness and polarization.
Both language capacity and strongly lateralized hand preference are among the most intriguing particularities of the human species. They are associated in the adult brain with functional and anatomical hemispheric asymmetries in the speech perception-production network and in the sensori-motor system.
In the quest to decipher the chain of life from molecules to cells, the biological and biophysical questions being asked increasingly demand techniques that are capable of identifying specific biomolecules in their native environment, and can measure biomolecular interactions quantitatively, at the smallest possible scale in space and time, without perturbing the system under observation.
Le prolongement de la durée d’exploitation des centrales nucléaires françaises soulève de nombreuses questions de recherche sur le vieillissement des ouvrages de génie civil nucléaire. Les phénomènes intervenant lors de ce vieillissement sont principalement liés au développement de pathologies, notamment les réactions de gonflements internes. Ces phénomènes sont susceptibles en particulier de dégrader le béton et de conduire à l’apparition de fissures dans les structures touchées.
The culture of microalgae is important for the production and maintenance of bivalves. One of the major challenges is to maintain the reliability of microalgae forages over the long term. The aim of this work is to use Ultrafiltered (UF) seawater to cultivate them.
This work concerns the wind-driven resuspension in a narrow marine channel and the risk of transport of contaminated bottom sediments in a wide brackish lagoon in the context of a planned anthropogenic infrastructure (with forced convection, by pumping sea water). It is based on the modelling and 3D numerical simulation of salinity, current distributions and bottom shear stress (BSS).