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The well-known Rayleigh�Plesset (RP) equation is the base of
nearly all hydrodynamical descriptions of the sonoluminescence
phenomenon. A major deficiency of this equation is that it
accounts for viscosity of an incompressible liquid and
compressibility, separately. By removing this approximation, we
have modified the RP equation, considering effects of liquid
second viscosity. This modification exhibits its importance at the
end of an intense collapse, so that the new model predicts the
appearance of a new picosecond bouncing during high-amplitude
sonoluminescence radiation. This new bouncing produces very sharp
(sub-picosecond) peaks on the top of the sonoluminescence pulse.
These new behaviours are more remarkable for higher driving
pressures and lower ambient temperatures
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