21 research outputs found
Stimuli Thresholds for Isomerization-Induced Molecular Motions in Azobenzene-Containing Materials.
We use large-scale molecular dynamics simulations of the isomerizations of azobenzene molecules diluted inside a simple molecular material to investigate the effect of a modification of the cis isomer shape on the induced diffusion mechanism. To this end we simulate incomplete isomerizations, modifying the amplitude of the trans-to-cis isomerization. We find thresholds in the evolution of the host molecules mobility with the isomerization amplitude, a result predicted by the cage-breaking mechanism hypothesis (Teboul, V.; Saiddine, M.; Nunzi, J. M.; Accary, J. B. J. Chem. Phys. 2011, 134, 114517) and by the gradient pressure mechanism theory (Barrett, C. J.; Rochon, P. L.; Natansohn, A. L. J. Chem. Phys. 1998, 109, 1505–1516.). Above the threshold the diffusion then increases linearly with the variation of the chromophore size induced by the isomerization
Wildfire behavior study in a Mediterranean pine stand using a physically based model
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Towards a Numerical Benchmark for 3D Low Mach Number Mixed Flows in a Rectangular Channel Heated from Below
Abstract: In the literature, only few references have dealt with mixed-convection flows in the low Mach number approximation. For this reason, in the present study we propose to extend the standard 3D benchmark for mixed convection in a rectangular channel heated from below (Medale and Nicolas, 2005) to the case of large temperature variations (for which the Boussinesq approximation is no longer valid). The Navier-Stokes equations, obtained under the assumption of a low Mach number flow, are solved using a finite volume method. The results, corresponding to the steady-state case of the benchmark, lead to the idea of launching a call for contribution (whose outlines still need to be defined) in order to set up a reference solution essential for the validation of future numerical codes