No abstract

Changes in the free volume in CYTOP due to pressure densification and swelling with CO2 have been examined using PALS and PVT experiments. Employing the Simha‐Somcynsky equation of state the specific hole free, Vf, and occupied, Vocc, volumes were estimated. The change in the total volume due to the pre‐treatments occurs exclusively in the hole free volume and the relative change in Vf is one order of magnitude larger than in the total volume. Vocc shows no memory for the history of the polymer glass. The mean and width of the size distribution of subnanometre holes in the glassy state decrease upon densification and increase upon swelling. The volume changes which are frozen in the polymer glass begin to recover at temperatures distinctly below Tg.magnified image

No abstract

Measurement of positron annihilation lifetime in a pairs of deformed magnesium specimens with deformations of up to 75% are discussed. The lifetime *BAR*τ*BAR* exhibits saturation: for deformations larger than those corresponding to a 15% thickness reduction. The lifetime varies from 231±2 ps for annealed magnesium to 249±2 for dislocation-saturated samples. The trapping cross section and trapping efficiency are calculated.