Comodoro Rivadavia, Argentina

University of Marina Mercante
Comodoro Rivadavia, Argentina
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Altenberg A.E.,Argentine Business University, Buenos Aires | Altenberg A.E.,University of Marina Mercante
Journal of Offshore Mechanics and Arctic Engineering | Year: 2011

A wavelet analysis of the behavior of a large spar platform model undergoing a monochromatic input wave excitation is presented. Two techniques are involved in this analysis. First, a continuous wavelet transform (CWT) with complex Morlet wavelets is performed. For this transform, special attention is given to the treatment of the signals ends by mean of stating adequate hypotheses on the behavior of the time series at their boundaries. Second, to validate the hypotheses on the boundary extensions made for the CWT analysis and to provide additional insight on the system behavior, a cubic B-spline discrete wavelet transform representation on a bounded interval is performed. This transform relies only on the interval data, giving in this way a truly semi-orthogonal representation of the energy density of the system on a bounded interval. In this manner, it becomes possible the analysis of wave tank experiments with spar platforms in which it is not possible to conduct tests involving long spans of data and making extrapolation assumptions can pose a question on the validity of the analysis. © 2011 American Society of Mechanical Engineers.

Bianchetti A.,National Institute of Industrial Technology | Sanchez S.H.,University of Buenos Aires | Cabaleiro J.M.,University of Buenos Aires | Cabaleiro J.M.,University of Marina Mercante
Microfluidics and Nanofluidics | Year: 2016

The build-up of pressure-driven backflows is a known drawback to electroosmotic plug flow. We have studied the characteristic time constant of these pressure gradients build-up as a function of various geometrical variables of the problem through μPIV measurements. Previous models based on hydrostatic pressure difference (syphoning) cannot explain the dynamics of our experimental results. We have developed a model that relates these pressure-driven backflows to Laplace pressures, due to changes in the interface radii of curvature at the reservoirs. This model leads to an equation which was solved both numerically and, after linearisation, analytically. The characteristic time constants obtained show much better agreement with experimental data. Therefore, this model allows for predicting the time during which an acceptable electroosmotic flow profile will last for a given microchannel–reservoir design. © 2016, Springer-Verlag Berlin Heidelberg.

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.

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.

Cabaleiro J.M.,University of Buenos Aires | Cabaleiro J.M.,University of Marina Mercante | Aider J.L.,Paris West University Nanterre La Défense | Artana G.,University of Buenos Aires | Wesfreid J.E.,Paris West University Nanterre La Défense
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.

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.

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.

University of Marina Mercante | Entity website

University of Marina Mercante | Entity website

University of Marina Mercante | Entity website

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