Fig. 16.

Effect of pulse-modulation cold air plasma jet on MRSA inactivation as a function of NP and treatment time. The bacteria were grown in nutrient broth prior to spreading on to agar plate. They were then exposed to the air plasma jet with the nozzle fixed at the center, 0.5 cm above the agar. The exposure was conducted for the indicated time period, and the bacteria were incubated at 37°C for 18–24 h before pictures were taken. The air plasma jet was generated under pulse-modulation condition: PW = 1, PD = 12, NP = 5, and BRR = 2. The plate diameter was 9 cm. MRSA, methicillin-resistant Staphylococcus aureus; NP, number of pulses in a burst; PW, pulse width; PD, pulse delay time; BRR, burst repetition rate.