Fig. 9
From: Effect of HIFU frequency on gold removal efficiency from e-waste
Removed gold volume normalized by the input electrical energy, as function of burst count. The data is the average of three experiments ± 1 SD. Largest volume (left) is calculated from the largest individual removed gold area, and total volume (right) from the sum of all removed gold areas. A maximum in largest volume removal efficiency is observed for all frequencies, after which removal rate diminishes. For 7.3 MHz the total volume removal rate does not reach a maximum, owing to significant removal within the sidelobe. Lines are shown to guide the eye.
