The diffusion coefficient in phase space usually varies with the particle energy. A consequence is the dependence of the fluid particle flux on the temperature gradient. If the diffusion coefficient in phase space decreases with the energy in the bulk of the thermal distribution function, the particle thermodiffusion coefficient which links the particle flux to the temperature gradient is negative. This is a possible explanation for the inward particle pinch that is observed in tokamaks. A quasilinear theory shows that such a thermodiffusion is generic for a tokamak electrostatic turbulence at low frequency. This effect adds to the particle flux associated with the radial gradient of magnetic field. This behavior is illustrated with a perturbed electric potential, for which the trajectories of charged particle guiding centers are calculated. The diffusion coefficient of particles is computed and compared to the quasilinear theory, which predicts a divergence at low velocity. It is shown that at low velocity, the actual diffusion coefficient increases, but remains lower than the quasilinear value. Nevertheless, this differential diffusion between cold and fast particles leads to an inward flux of particles.

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Composite materials have vast range of engineering applications because of their outstanding mechanical performance, low density and cost effectiveness. Marine industry and naval structures are one of the applications where composites are gaining importance rapidly however, there are confronted with extreme environmental conditions in addition mechanical behaviour. Therefore, it is important to comprehend the behaviour of these materials not only under mechanical loads but also under environmental effects. For that reason, the objective of this paper is to study the effects of hygrothermal aging phenomenon on the behaviour of adhesively bonded composite joints at high strain rates. Dynamic compressive properties and microstructural damage progression is analysed utilizing the Split Hopkinson Pressure Bars (SHPB) technique. The stress-strain behaviour of composite specimens subjected to severe hygrothermal conditions have been studied at high strain rates ranging from 445 to 1240 s -1 . In addition, Keyence and scanning electron microscopic (SEM) is used to study the significant damage modes. The results indicated change in dynamic properties and damage behaviour because of the environmental effects.