No abstract

Glasses are known to undergo spontaneous densification during isothermal annealing. This volume recovery process can be viewed as collapse of free volume. We have modeled this change in free volume during annealing as a vacancy diffusion process, where the diffusion constant depends on the local free volume (as defined by the Simha-Somcynsky theory) through the Doolittle equation. Good agreement was obtained with estimates of experimental volume recovery results for poly(vinyl acetate). Since volume recovery is sample-size independent, the characteristic length for diffusion cannot be identified with macroscopic dimensions. Several possibilities exist that can reconcile a diffusion picture with the known sample-size independence of the volume recovery process. These possibilities include internal annihilation of vacancies, density fluctuations, and a coupling of diffusive and uniform lattice motions.

No abstract

Wescreened for fungi that can decolorize molasses melanoidin in the tropical zone and isolated some strains, mainly in the genus Aspergillus. Of these, strain No. G-2-6 was most active and was identical with Aspergillus fumigatus based on detailed morphological studies. This strain decolorized about 75%of a molasses melanoidin solution when the strain was cultivated on a glycerol-peptone medium at 45°C for 3 days with shaking. In successive