Fig. 7

The target samples after ultrasonic cleaning and drying. (a) The target samples after ultrasonic cleaning and drying after the SPE tests; (b) The target samples after ultrasonic cleaning and drying after 90Â min WDE tests.
The target samples after ultrasonic cleaning and drying. (a) The target samples after ultrasonic cleaning and drying after the SPE tests; (b) The target samples after ultrasonic cleaning and drying after 90Â min WDE tests.