A new approach to the monitoring of granulation processes using passive acoustics together with precise control over the granulation process has highlighted the importance of particle-particle and particle-bowl collisions in acoustic emission. The results have shown that repeatable acoustic results could be obtained but only when a spray nozzle water addition system was used. Acoustic emissions...

. Vibro-acoustography (VA) is an acoustic image modality based on the response of tissue under excitation of two ultrasound beams with different-frequencies. The aim of this paper is to provide a quantitative analysis with experimental measurements of the difference-frequency (DF) pressure generated in VA. This analysis considered the radiation force , the induced acoustic emission, and nonline...