Regarding the oscillation in the ∆ƒshort-z and Fcons, short-z curves, no obvious difference was found in amplitude between the sample heated for 16 h and the sample left at room temperature for 74 h, though the ∆ƒshort oscillation of the 142 h-settling sample almost disappeared. Taking the interpretation that 74 h of settling at room temperature is equivalent to 16 h of heating with subsequent 24 h of settling, the shift factor aT, short and the activation energy ∆Eshort are calculated to be aT, short = (74-24)/16 = 3.1 and Eshort = 18 kJ mol -1 . These values are almost similar to those of the bulk viscoelastic relaxation (aT, η=2.9 and Eη =17 kJ mol -1 ).