Rochechouart 2017-Drilling Campaign: First Results

No abstract available

Role of Gas6 Receptors in Platelet Signaling during Thrombus Stabilization and Implications for Antithrombotic Therapy

Mechanisms regulating thrombus stabilization remain largely unknown. Here, we report that loss of any 1 of the Gas6 receptors (Gas6-Rs), i.e., Tyro3, Axl, or Mer, or delivery of a soluble extracellular domain of Axl that traps Gas6 protects mice against life-threatening thrombosis. Loss of a Gas6-R does not prevent initial platelet aggregation but impairs subsequent stabilization of platelet aggregates, at least in part by reducing “outside-in” signaling and platelet granule secretion. Gas6, through its receptors, activates PI3K and Akt and stimulates tyrosine phosphorylation of the β3 integrin, thereby amplifying outside-in signaling via αIIbβ3. Blocking the Gas6-R–αIIbβ3 integrin cross-talk might be a novel approach to the reduction of thrombosis

CIRIR programs: drilling and research opportunities at the Rochechouart Impact Structure

International audienc

Continuum Mechanics and Thermodynamics manuscript No. (will

be inserted by the editor

A finite-strain model for an explosive simulant

On propose un modèle de comportement isotherme en transformations finies pour l'équivalent inerte d'un explosif. Il décrit les processus dissipatifs correspondant à deux mécanismes différents dont l'un est plastique avec dilatance et l'autre est de type viscoélastique. Ce modèle est ensuite implanté dans le code EPIC-2 et utilisé pour simuler des expériences d'impact de plaques.An isothermal finite strain constitutive modelling for the mechanical behaviour of an explosive simulant is presented. It accounts for two different dissipative processes including dilatational plasticity and a complementary viscous mechanism (viscoelastic-like). This model is implemented into the EPIC-2 hydrocode and used to simulate plate impact experiments

Mechanical and microstructural characterization of a HMX-based pressed explosive: Effects of combined high pressure and strain rate

The paper presents a study of the combined effects of strain rate and confining pressure on the behaviour and microstructure evolutions of a HMX-based explosive. Hopkinson bar compression experiments are carried-out on samples confined with a brass sleeve. The latter is instrumented in order to determine the confining pressure on the explosive sample, directly function of the sleeve thickness and yield strength. A sample confined at 75 MPa and deformed at 250s−1 is recovered, cross-sectioned and studied using optical microscopy. Distributed microplasticity and microcracking appear similar to those induced by confined quasi-static experiments, indicating that stress triaxiality is the most important loading parameter. The sample also displays a large shear macrocrack, resulting from the formation of an adiabatic shear band. Shear banding seems to proceed by strong plastic strain gradients, followed by dynamic re-crystallization. Further strong thermal effects are observed, resulting in local reactive melting