Publications de Nicolas Dorsaz

Detailed experiments on weakly deformed cavitation bubbles

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Outi Supponen

We present high-precision experiments conducted with the aim to better characterise weak deformations of single cavitation bubbles. Using two needle hydrophones and a high-speed photodetector, we record the timings of shock waves and luminescence emitted a ...

SPRINGER2019

Shock waves from nonspherical cavitation bubbles

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Marc Tinguely, Outi Supponen

We present detailed observations of the shock waves emitted at the collapse of single cavitation bubbles using simultaneous time-resolved shadowgraphy and hydrophone pressure measurements. The geometry of the bubbles is systematically varied from spherical ...

Amer Physical Soc2017

Scaling laws for jets of single cavitation bubbles

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Marc Tinguely, Outi Supponen

Fast liquid jets, called micro-jets, are produced within cavitation bubbles experiencing an aspherical collapse. Here we review micro-jets of different origins, scales and appearances, and propose a unified framework to describe their dynamics by using an ...

Cambridge University Press2016

Hard sphere-like glass transition in eye lens alpha-crystallin solutions

Nicolas Dorsaz, Giuseppe Foffi

We study the equilibrium liquid structure and dynamics of dilute and concentrated bovine eye lens alpha-crystallin solutions, using small-angle X-ray scattering, static and dynamic light scattering, viscometry, molecular dynamics simulations, and mode-coup ...

National Academy of Sciences2014

The quest for the most spherical bubble: experimental setup and data overview

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Marc Tinguely, Aurèle De Bosset

We describe a recently realized experiment producing the most spherical cavitation bubbles today. The bubbles grow inside a liquid from a point plasma generated by a nanosecond laser pulse. Unlike in previous studies, the laser is focussed by a parabolic m ...

Springer Verlag2013

Energy partition at the collapse of spherical cavitation bubbles

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Marc Tinguely, Aurèle De Bosset

Spherically collapsing cavitation bubbles produce a shock wave followed by a rebound bubble. Here we present a systematic investigation of the energy partition between the rebound and the shock. Highly spherical cavitation bubbles are produced in micrograv ...

American Physical Society2012

Arrested demixing opens route to bigels

Nicolas Dorsaz, Giuseppe Foffi, Francesco Varrato, Maxim Belushkin

Understanding and, ultimately, controlling the properties of amorphous materials is one of the key goals of material science. Among the different amorphous structures, a very important role is played by colloidal gels. It has been only recently understood ...

National Academy of Sciences2012

Phase separation in binary eye lens protein mixtures

Nicolas Dorsaz, Giuseppe Foffi

Liquid–liquid phase separation occurs in young mammalian eye lenses and in concentrated solutions of isolated eye lens proteins, and has been linked to some forms of cataract. Here we study theoretically the protein compositions and cloud temperatures of t ...

2011

Confined shocks inside isolated liquid volumes: A new path of erosion?

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Marc Tinguely, Aurèle De Bosset

The unique confinement of shock waves inside isolated liquid volumes amplifies the density of shock–liquid interactions. We investigate this universal principle through an interdisciplinary study of shock-induced cavitation inside liquid volumes, isolated ...

American Institute of Physics2011

Bubbles in drops: from cavitation to exploding stars

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Marc Tinguely, Aurèle De Bosset

APS2011

Inertial effects in diffusion-limited reactions

Nicolas Dorsaz, Francesco Piazza, Giuseppe Foffi

Diffusion-limited reactions are commonly found in biochemical processes such as enzyme catalysis, colloid and protein aggregation and binding between different macromolecules in cells. Usually, such reactions are modeled within the Smoluchowski framework b ...

Institute of Physics2010

Phase behaviour of the symmetric binary mixture from Thermodynamic Perturbation Theory

Nicolas Dorsaz, Giuseppe Foffi

We study the phase behaviour of symmetric binary mixtures of hard core Yukawa (HCY) particles via thermodynamic perturbation theory (TPT). We show that all the topologies of phase diagram reported for the symmetric binary mixtures are correctly reproduced ...

2010

A colloidal approach to eye lens protein mixtures : relevance for cataract formation

Nicolas Dorsaz

A broad and constantly growing class of diseases, such as Alzheimer's disease, sickle-cell or cataract, involves protein association phenomena as an essential aspect. The common denominator of all the members of this class of molecular condensation disease ...

EPFL2009

Spinodal surface of a free energy model for eye lens protein mixtures: Relevance for cataracts

Nicolas Dorsaz, Giuseppe Foffi

We studied the phase behavior of a model binary mixture of eye lens crystallin proteins using first-order thermodynamic perturbation theory. The instability boundary, or spinodal surface, was found to be very sensitive to the strength of the attraction bet ...

Amer Inst Physics, 2 Huntington Quadrangle, Ste 1No1 D, Melville, Ny 11747-4501 Usa2009

Colloidal characterization and thermodynamic stability of binary eye lens protein mixtures

Nicolas Dorsaz, Giuseppe Foffi

We present a study of binary mixtures of eye lens crystallin proteins. A coarse-grained model of aqueous aand γ-crystallin mixtures based on molecular dynamics simulations and SANS experiments is proposed. Thermodynamic perturbation theory is implemented t ...

2009

Techniques for generating centimetric drops in microgravity and application to cavitation studies

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Aurèle De Bosset

This paper describes the techniques and physical parameters used to produce stable centimetric water drops in microgravity, and to study single cavitation bubbles inside such drops (Parabolic Flight Campaigns, European Space Agency ESA). While the main sci ...

2009

New insight into cataract formation: Enhanced stability through mutual attraction

Nicolas Dorsaz, Giuseppe Foffi

Small-angle neutron scattering experiments and molecular dynamics simulations combined with an application of concepts from soft matter physics to complex protein mixtures provide new insight into the stability of eye lens protein mixtures. Exploring this ...

2007

Interaction of a cavitation bubble with a spherical free surface

Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Aurèle De Bosset

The dynamic of a cavitation bubble inside a water drop is investigated in microgravity in order to analyze the interaction between the collapsing bubble and a quasispherical free surface. Tests are carried in the frame of the 42nd parabolic flight campaign ...

2006

Cavitation Bubble Dynamics inside Liquid Drops in Microgravity

Claude Nicollier, Mohamed Farhat, Danail Obreschkow, Nicolas Dorsaz, Philipp Kobel, Aurèle De Bosset

We report a fundamental study of single cavitation bubbles inside quasi-spherical water drops produced in microgravity (42nd ESA parabolic flight campaign, 8th ESA student parabolic flight campaign). High-speed imaging revealed implications of isolated, fi ...

2006