Publications de Gérard Gremaud

A link between short-range and long-range properties of random sphere packings

Daniele Mari, Gérard Gremaud, Arnaud Comment, Riccardo Balzan, Alessandro Luigi Sellerio

We present a high precision particle-by-particle 3D reconstruction of granular systems composed of monodispersed spheres (sphere packings); the experimental approach is based on magnetic resonance imaging techniques. Our measurements revealed a strong corr ...

Springer Berlin Heidelberg2013

Friction and Hertzian contact in granular glass

Daniele Mari, Gérard Gremaud, Alessandro Luigi Sellerio

We study the jamming process arising in granular systems subjected to decreasing external vibration, which has features similar to the cooling of glass-forming liquids. We modify the friction between grains and observe that jamming occurs 'more easily' for ...

Iop Publishing Ltd2013

Fractional Brownian motion and anomalous diffusion in vibrated granular materials

Daniele Mari, Gérard Gremaud, Alessandro Luigi Sellerio

We propose a new approach to the study of diffusion dynamics in vibrated granular systems. The dynamic of a granular material is mainly defined by dry friction interactions. This type of interaction is difficult to model for a large quantity of particles. ...

2012

A new MRI reconstruction technique based on real space Hough transform for granular samples

Daniele Mari, Gérard Gremaud, Arnaud Comment, Riccardo Balzan, Alessandro Luigi Sellerio

2012

Glass transition associated with the jamming of vibrated granular matter

Daniele Mari, Gérard Gremaud, Alessandro Luigi Sellerio

We investigate a vibrated granular system composed of millimeter-size glass beads. When the system is submitted to a perturbation with decreasing intensity, below the fluidization limit, it evolves in a way similar to glass-forming liquids until it reaches ...

2011

Hard X-ray imaging for landslide research

Gérard Gremaud

Synchrotron phase-contrast hard X-ray imaging is used to provide highly efficient direct visualization of landslide dynamics and granular flows in fully wet granular piles. High penetration capability and phase-contrast enhancement of hard X-rays offer mar ...

2010

Intracellular nanomanipulation by a photonic-force microscope with real-time acquisition of a 3D stiffness matrix

Michaël Unser, László Forró, Giovanni Dietler, Andrzej Kulik, Philippe Thévenaz, Elena Bertseva, Gérard Gremaud, Sylvia Jeney, Stefania Puttini, Amardeep Singh

A traditional photonic-force microscope (PFM) results in huge sets of data, which requires tedious numerical analysis. In this paper, we propose instead an analog signal processor to attain real-time capabilities while retaining the richness of the traditi ...

Institute of Physics2009

Theory of plasticity and anelasticity due to dislocation creep through a multi-scale hierarchy of obstacles

Gérard Gremaud

The creep of a dislocation on its glide plane is essentially controlled by three different stress fields: the external applied stress, the internal stress field due to a multi-scale hierarchy of different obstacles (the structural defects acting on the dis ...

2009

Glassy and liquid vortex matter dynamics in faulted martensites

Gérard Gremaud

We consider dislocations as vortices in elastic strain field and show that an ordered system of partial dislocations in faulted martensites is analogous to a system of flux lines (supercurrent vortices) in type-II superconductors. The network of interactin ...

2008

Adhesion hysteresis and friction at nanometer and micrometer lengths

Andrzej Kulik, Gérard Gremaud

2006