The role of the dorsal anterior insula in ecstatic sensation revealed by direct electrical brain stimulation

International audienc

Validating Injection Stretch-Blow Molding Simulation Through Free Blow Trials

International audienceA 2D isothermal finite element simulation of the injection stretch-blow molding (ISBM) process for polyethylene terephthalate (PET) containers has been developed through the commercial finite element package ABAQUS/standard. In this work, the blowing air to inflate the PET preform was modeled through two different approaches: a direct pressure input (as measured in the blowing machine) and a constant mass flow rate input (based on a pressure-volume-time relationship). The results from these two approaches were validated against free blow and free stretch-blow experiments, which were instrumented and monitored through highspeed video. Results show that simulation using a constant mass flow rate approach gave a better prediction of volume vs. time curve and preform shape evolution when compared with the direct pressure approach and hence is more appropriate in modeling the preblowing stage in the injection stretch-blow molding process

Single Fiber Transport in a Fracture Slit: Influence of the Wall Roughness and of the Fiber Flexibility

International audienceThe transport of fibers by a fluid flow is investigated in transparent channels modelling rock fractures: the experiments use flexible polyester thread (mean diameter $280 \mu\mathrm{m}$) and water or a water-polymer solution. For a channel with smooth parallel walls and a mean aperture $\bar{a} = 0.65\,\mathrm{mm}$, both fiber segments of length $\ell = 20-150\, \mathrm{mm}$ and ``continuous'' fibers longer than the channel length have been used: in both cases, the velocity of the fibers and its variation with distance could be accounted for while neglecting friction with the walls. For rough self-affine walls and a continuous gradient of the local mean aperture transverse to the flow, transport of the fibers by a water flow is only possible in the region of larger aperture ($\bar{a} \gtrsim 1.1 \mathrm{mm}$) and is of ``stop and go'' type at low velocities. With the polymer solution, the fibers move faster and more continuously in high aperture regions and their interaction with the walls is reduced; fiber transport becomes also possible in narrower regions where irreversible pinning occurred for water. In a third rough model with parallel walls and a low mean aperture $\bar{a}=0.65 \mathrm{mm}$, fiber transport is only possible with the water-polymer solution. The dynamics of fiber deformations and entanglement during pinning-depinning events and permanent pinning is analyzed