Hysteresis associated with capillary condensation and evapora-
tion in porous materials has been the subject of immense interest
for over 100 years [1], especially the search for the controlling
mechanisms of adsorption and desorption. Adsorption in mesop-
ores gives rise to hysteresis when the temperature is less than
the critical hysteresis temperature and pore size is greater than a
critical value [2,3].