Figure 6.

(Color online) Histograms (20 bins) of the static pressure threshold for both UCA populations, (a) Point and (b) Philips, suggested a multi-modal distribution. A k-means algorithm divided the pressure data into two groups: a primary group and a secondary group. Additional, a third category of UCAs that remained intact during the experimental runs were present in Point and Philips UCAs. The estimated probability densities of the rupture pressures for the collective and individual groups for Point UCA is shown in (c) and that for the Philips UCA is shown in (d).