  Acoustic waves are dissipated when they pass through bubbly media.
Dissipation by bubbles takes place through thermal damping (Td), radiation
damping (Rd) and damping due to the friction of the liquid (Ld) and friction of
the coating (Cd). Knowledge of the contributions of the Td, Rd, Ld and Cd
during nonlinear bubble oscillations will help in optimizing bubble and
ultrasound exposure parameters for the relevant applications by maximizing a
desirable parameter. In this work we investigate the mechanisms of dissipation
in bubble oscillations and their contribution to the total damping (Wtotal) in
various nonlinear regimes. By using bifurcation analysis, we have classified
nonlinear dynamics of bubbles that are sonicated with their 3rd superharmonic
(SuH) and 2nd SuH resonance frequency (fr), pressure dependent resonance
frequency (PDfr), fr, subharmonic (SH) resonance (fsh=2fr), pressure dependent
SH resonance (PDfsh) and 1/3 order SH resonance. The corresponding Td, Rd, Ld,
Cd, Wtotal, scattering to dissipation ratio (STDR), maximum wall velocity and
maximum back-scattered pressure from non-destructive oscillations of bubbles
were calculated and analyzed using the bifurcation diagrams. We classified
different regimes of dissipation and provided parameter regions in which a
particular parameter of interest (e.g. Rd) can be enhanced. Afterwards enhanced
bubble activity is linked to some relevant applications in ultrasound. This
paper represents the first comprehensive analysis of the nonlinear oscillations
regimes and the corresponding damping mechanisms.
