Nonlinear scatter from Sonazoid

Presents a nonlinear model for the response of shell-encapsulated gas bubbles to an ultrasound pulse. Values for the viscoelastic properties of the shell were estimated from ultrasound measurements at low amplitude. Results from simulations were compared with experiments. Ultrasound pulses were transmitted with a 1 MHz transducer into samples of Sonazoid. Pressure amplitudes were varied between 20 and 500 kPa. In the received echoes, frequency components up to the 9th harmonic of the transmit frequency were detected. Good agreement was found between the experimental results and predictions from the theory. Theories based on gas-bubbles without shell give poor agreement between theoretical and experimental results