The contour lines for tR exhibit slopes akin to the ReOh = 2 line, while those for tvisc display slightly flatter slopes in the Oh versus Re log-log plots. The contour lines indicate that both tR and tvisc values rise with increasing Re and Oh, as illustrated by arrows in Figure . it is important to note that a higher t R signifies a slower rate of bubble formation, whereas a higher tvisc suggests increased stability of bubbles/foams. The occurrence of foaming requires a delicate balance between bubble formation and the stability of bubbles/foams.