Isothermal mass transfer

This is often referred to as isothermal mass transfer since it does not require a thermal gradient. When two different metals are separated by a... 

We consider either isothermal mass transfer (Gq == 0) or uniform composition heat transfer (Gr = 0) from a particle with constant surface composition or temperature. The Rayleigh number Ra is used for both GqPr and Gr Sc. 

Finally, Delancey and Chiang5 3,54 reported a general mathematical evaluation of multicomponent non isothermal mass transfer in the presence as well as absence of a chemical reaction. These studies followed the matrix approach to the problem. The chemical reaction considered was a simple first-order irreversible reaction. The problem was solved assuming time dependence of the rate constant and an exponential relationship between the temperature and the distance. 

The Thomson (Kelvin) law is the basis for the description of such phenomena as capillary condensation, nucleation (Chapter IV) and the isothermal mass transfer of substances (see Chapter VII). 

In various areas of science and applications, where these basic mechanisms of system destabilization play an important role, different terms, often specific to a particular area of application, are used as synonyms. For instance, the isothermal mass transfer taking place in solid materials is referred to as recrystallization, or coalescence of inclusions in the case of two-phase systems (we will further avoid the use of term coalescence in such sense). Such process taking place in precipitates is referred to as the Ostwald ripening. The fusion of solid particles (in many cases similar to coalescence) is known as sintering. 

Depending on the aggregate state of dispersion medium, isothermal mass transfer, coagulation and coalescence may play different roles in the loss of stability of disperse systems towards aggregation. Coagulation, coalescence, and phase separation during sedimentation are typical in systems with liquid... 

These deaggregated particles are in the state of partial equilibrium their aggregation is thermodynamically unfavorable, while isothermal mass transfer and coalescence, leading to a decrease in degree of dispersion, are possible. At the same time, if isothermal mass transfer does not occur within realistic observation time periods, the equilibrium from partial turns into complete the... 

In systems that initially reveal sedimentation stability, particle coagulation, as well as particle growth due to subsequent coalescence or isothermal mass transfer, may result in a loss of sedimentation stability. At the same time, coagulation may not necessarily be followed by phase separation due to sedimentation, as in the case when particle aggregation results in formation of continuous three-dimensional networks of particles that fill an... 

VII.7. The Influence of Isothermal Mass Transfer (Ostwald Ripening) on the Decrease in Degree of Dispersion... 

Thus during the steady-state stage of isothermal mass transfer the cube of average radius grows linearly with time the growth rate is a function of interfacial tension, as well as of the solubility and diffusion coefficient of dispersed substance. If an admixture that is nearly insoluble in a continuous phase is introduced into the dispersion phase, a sharp decrease in recondensation rate, as well as changes in laws describing the process, may take place. 

Isothermal mass transfer plays an important role in the transition of substance from convex surfaces to concave ones it stipulates the concretion, as well as sintering of solid particles that are in direct contact with each other. 

Problems of isothermal mass transfer and reaction are best represented in terms of the species continuity equation and the associated jump condition. We repeat these two... 

Chung, T. S., and Teoh, S. K. (1997). Breaking the limitation of composition change during isothermal mass-transfer processes at the spinodal. J. Membr. Sci. 130, 141. 

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