Hysteresis, separation processes

The kinetics of nucleation/growth and separation processes in an ensemble of nanoparticles under time-dependent temperature is presented. Grounding upon our numerical studies, we conclude that under temperature cycling one should observe a hysteresis behavior. Such hysteresis is conditioned by the finite size and depletion effects and is described on the basis of the kinetic equation approach. The model shows that the width of hysteresis loop depends on (i) thermodynamic... 

The adhesion hysteresis and its contribution to the friction have been studied extensively by means of SFA [39], which leads to an important conclusion that it is the adhesion hysteresis or the energy loss during the process of approach/separation, rather than the surface energy itself, that dominates the frictional behavior of boundary films. 

The ferroelectric hysteresis originates from the existence of irreversible polarization processes by polarization reversals of a single ferroelectric lattice cell (see Section 1.4.1). However, the exact interplay between this fundamental process, domain walls, defects and the overall appearance of the ferroelectric hysteresis is still not precisely known. The separation of the total polarization into reversible and irreversible contributions might facilitate the understanding of ferroelectric polarization mechanisms. Especially, the irreversible processes would be important for ferroelectric memory devices, since the reversible processes cannot be used to store information. 

In monolayer adsorption all the adsorbed molecules are in contact with the surface layer of the adsorbent. In multilayer adsorption the adsorption space accommodates more than one layer of molecules so that not all adsorbed molecules are in direct contact with the surface layer of the adsorbent. In capillary condensation the residual pore space which remains after multilayer adsorption has occurred is filled with condensate separated from the gas phase by menisci. Capillary condensation is often accompanied by hysteresis. The term capillary condensation should not be used to describe micropore filling because this process does not involve the formation of liquid menisci. 

The use of frontal chromatography would appear to avoid the errors produced by hysteresis in that the sorption and desorption processes can be separated in time. An extensive study of this method for water sorption, using freeze-dried coffee as a... 

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