DETERMINATION OF THE RADII OF GAS CAVITATION NUCLEI BY FILTERING GELATIN

We report an experiment in which the size distributions of the entities which initiate bubble formation in supersaturated gelatin are systematically altered by passing test samples through Nuclepore filters with nominal pore diameters of 0.4, 0.6, 0.8, 1.0, and 3.0 μm. The actual diameters range from +0% to — 20% of the nominal values. The data are compared with a new model, described in the previous article, in which gas cavitation nuclei are stabilized by surface-active skins of varying gas permeability. Within the measurement resolution, the initial cutoff radii for bubble formation are the same as the respective filter-pore radii. This implies that the calculated radii are those of actual physical structures capable of initiating bubble formation in gelatin. © 1979, Acoustical Society of America. All rights reserved.