Fig. 2: Equilibration of water vapor saturation.
From: Ultrasound propagation in water-sorbing carbon xerogel
Variation of the travel time of the longitudinal wave with the exposure time of the sample a after changing RH from 48% to 12% and b to each RH level from 30% to 88%. c Variation of the travel time of the longitudinal wave and the sample mass with the exposure time of the sample at 93% RH (filled markers) and 98% RH (empty markers). d % Change of longitudinal speed (vL), bulk density (ρb) and the longitudinal modulus (M) with the exposure time of the sample at 93% RH. Note: the base time, t = 0 is taken when the sample is exposed to 93% RH after equilibration at 88% RH. e Cracks observed along the axial direction of the sister sample at (I) 84% RH and (II) 77% RH during desorption (similar cracks were observed on the sample used for ultrasonic measurements after the experiment was completed). f Growth of additional longitudinal peak in the waveforms measured over the time at 84% RH.
