Nelson Ibaseta

Ecole Centrale de Marseille · Mécanique, Modélisation & Procédés Propres, M2P2 (UMR AMU/CNRS/ECM 7340)

Due to the enormous increase in nanopowder production, it becomes necessary to find and develop adapted characterization techniques. In the case of nanostructured agglomerates, the structure of these particles has a direct impact on flowing, and handling, but also on end-use final product properties. In this work, a fractal approach is used to char...

An accurate 2-D numerical model that accounts for concentration polarization and osmotic effects is developed for the cross-flow filtration in a membrane channel. Focused on the coupling between laminar hydrodynamics and mass transfer, the numerical approach solves the solute conservation equation together with the steady Navier-Stokes equations un...

This work studies how deeply the reagents choice influences micromixing characterisation by the Villermaux-Dushman method, when applying it to a 1 litre stainless steel standard vessel with two baffles, stirred by an inclined blade turbine. For the first time, borate and phosphate buffer are compared on their use in the method. It is observed that...

To date, there is no information on the microfluidic emulsification of dibutyl adipate and n-butyl acetate in water. Since these solvents are very suitable for microencapsulation by interfacial polymerization, it is highly necessary to study the emulsification behavior of these solvents in microchannel. This work shows that the microfluidic emulsif...

The performance of reverse osmosis and tight nanofiltration with flat-sheet membranes can be predicted accurately. The proposed numerical model solves the local momentum and mass conservation equations in the module's feed channel with solution-diffusion boundary conditions. Both qualitative and quantitative predictions of the permeate flux and of...

The common chemical ultraviolet (UV) filters such as octyl salicylate that are used in sunscreen cream may cause irritation and other unknown medical conditions. One possible route to avoid the direct contact of UV filters with human skin is to enclose those filters in microcapsules. In this study, microcapsules with a size calibrated at 78 μm via...

There are some studies on the synthesis of polyurea microcapsules. However, there is hardly a case where both green solvents and non-toxic isocyanates are used, especially in microfluidics. In this work, an environmentally friendly chemical system of interfacial polymerization (isocyanate: HDB-LV; solvent: octyl salicylate or dibutyl adipate) is te...

In cross-flow membrane filtration, fouling results from material deposit which clogs the membrane inner surface. This hinders filtration, which experiences the so-called limiting flux. Among the models proposed by the literature, we retain a simple one: a steady-state reversible fouling is modelled with the use of a single additional parameter, i.e...

Membrane solute permeability plays a role in the buildup of concentration polarization in pressure-driven crossflow filtration processes, and thus in the determination of the permeate flux, solute rejection, retentate flux and concentration. We numerically examine reverse-osmosis desalination with membranes of fixed solvent permeability, but of var...

A novel experimental method and its associated model are proposed for the simultaneous determination of membrane solute and solvent permeabilities, which are essential transport parameters of reverse osmosis models used for process simulation. The method utilizes a single bench-scale batch apparatus consisting of two stirred half-cells containing s...

Concentration polarization affects numerous systems of membrane separation, and combined with osmosis, it can cause substantial reductions in permeation. We establish an exact solution to the conservation law of a solute advected by Berman flow. This flow is characteristic of reverse osmosis or nanofiltration. The resulting concentration polarizati...

A nanodustiness test is proposed as a useful device for the assessment of ultrafine aerosol emission by free falling nanopowders. This test is made of a 180*50*80 cm chamber, where the nanostructured powder is stocked in a silo with variable height. After the powder fall, the size distribution and concentration of the emitted aerosol are measured b...

In the last few years, the interest on nanomaterials and their applications have increased in a considerable way. Hence, the knowledge of the possible hazards on human health becomes necessary. Besides the description of the toxicological effects of nanomaterials, the exposure level on the worksites is one of the key data of the problem. The presen...

Lors de ces dernières années, on constate une croissance considérable des procédés de production de nanoparticules, dont la taille est inférieure à 100 nm. Des questions se posent alors à propos des risques pour l’homme et pour l’environnement associés à la production, à la manipulation et à l’usage des nanoparticules. L’objectif de ce travail est...

Due to the increasing production and development of nanoparticles, it has become necessary to control the exposure to ultrafine particles when handling nanopowders. The use of dustiness tests makes it possible to compare the ability of a given powder to re-suspend particles, and to determine the effect of the different external (powder handling met...

L’optimisation est un ensemble de techniques permettant de trouver les valeurs des variables qui rendent optimale une fonction objectif afin de déterminer les meilleures conditions opératoires. La plupart des méthodes d’optimisation ont été développées pour traiter le problème d’un point de vue mathématique, en supposant que le procédé peut être dé...