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Comodoro Rivadavia, Argentina

Conde A.J.,National University of Tucuman | Batalla M.,CONICET | Cerda B.,CONICET | Mykhaylyk O.,TU Munich | And 6 more authors.
Lab on a Chip - Miniaturisation for Chemistry and Biology | Year: 2014

We present a low-cost, portable microfluidic platform that uses laminated polymethylmethacrylate chips, peristaltic micropumps and LEGO® Mindstorms components for the generation of magnetoliposomes that does not require extrusion steps. Mixtures of lipids reconstituted in ethanol and an aqueous phase were injected independently in order to generate a combination of laminar flows in such a way that we could effectively achieve four hydrodynamic focused nanovesicle generation streams. Monodisperse magnetoliposomes with characteristics comparable to those obtained by traditional methods have been obtained. The magnetoliposomes are responsive to external magnetic field gradients, a result that suggests that the nanovesicles can be used in research and applications in nanomedicine. This journal is © the Partner Organisations 2014. Source

Cabaleiro J.M.,University of Buenos Aires | Cabaleiro J.M.,University of Marina Mercante | Aider J.-L.,University Pierre and Marie Curie | Aider J.-L.,University Paris Diderot
Physics of Fluids | Year: 2014

In this study, it is shown that free microjets can undergo complex transitions similar to large-scale free jets despite relatively low Reynolds numbers. Using an original experimental method allowing for the 3D reconstruction of the instantaneous spatial organization of the microjet, the axis-switching of a micro-jet is observed for the first time. This is the first experimental evidence of such complex phenomena for free micro-jets. Combining these experimental results with Direct Numerical Simulations it is shown that themechanism responsible for the axis-switching is the deformation of a micro-vortex ring due to induction by the corner vortices, as it occurs in large scale non-circular jets. © 2014 AIP Publishing LLC. Source

Cabaleiro J.,University of Buenos Aires | Cabaleiro J.,University of Marina Mercante | Paillat T.,University of Poitiers | Touchard G.,University of Poitiers
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2014

From the moment a liquid is put in contact with a solid, physico-chemical reactions occur at their interface. These reactions have been modeled over the years by preferential adsorption or corrosion. Whatever the model, they lead to a charge distribution called electrical double layer (EDL), formed by a charge layer at the solid wall, and a diffuse charge layer of opposite sign in the liquid. In this work we focus on the formation of the EDL when a plane wall is put in contact with a quiescent fluid. The governing equations and a semi-analytical solution are presented. A simpler solution can be found by assuming the instantaneous formation of the charge density profile. The semi-analytical solution presented in this work is compared to the former at different reaction rates leading to the conclusion that for fast enough wall reactions, the instantaneous charge density profile cannot be assumed. © 2014 IEEE. Source

Cabaleiro J.M.,University of Buenos Aires | Cabaleiro J.M.,University of Marina Mercante | Aider J.L.,Paris West University Nanterre La Defense | Artana G.,University of Buenos Aires | Wesfreid J.E.,Paris West University Nanterre La Defense
Journal of Visualization | Year: 2013

Experimental characterization of micro-jets is challenging because of the small dimensions of the micro-nozzle. In this study, we propose a new technique to visualize the instantaneous 3D structure of a pulsed gas micro-jet. Using phase-averaging of Schlieren visualizations obtained with a high-speed camera and 3D reconstruction through a filtered back projection algorithm, it is possible to follow the high-speed dynamics of the pulsed jet. The experimental technique is illustrated by a 3D reconstruction of a pulsed helium micro-jet. The technique is simple yet very useful. To our knowledge, it is the only experimental method to analyze the instantaneous 3D structure and high frequency dynamics of pulsed micro-jets. Graphical Abstract: [Figure not available: see fulltext.] © 2013 The Visualization Society of Japan. Source

Cabaleiro J.M.,University of Buenos Aires | Cabaleiro J.M.,University of Marina Mercante | Laborde C.,University of Buenos Aires | Artana G.,University of Buenos Aires
Physics of Fluids | Year: 2015

In the present work, we study the starting transient of an immersed micro-jet in close vicinity to a solid wall parallel to its axis. The experiments concern laminar jets (Re < 200) issuing from a 100 μm internal tip diameter glass micro-pipette. The effect of the confinement was studied placing the micro-pipette at different distances from the wall. The characterization of the jet was carried out by visualizations on which the morphology of the vortex head and trajectories was analyzed. Numerical simulations were used as a complementary tool for the analysis. The jet remains stable for very long distances away from the tip allowing for a similarity analysis. The self-similar behavior of the starting jet has been studied in terms of the frontline position with time. A symmetric and a wall dominated regime could be identified. The starting jet in the wall type regime, and in the symmetric regime as well, develops a self-similar behavior that has a relative rapid loss of memory of the preceding condition of the flow. Scaling for both regimes are those that correspond to viscous dominated flows. © 2015 AIP Publishing LLC. Source

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