Fig. 7

Dnom ST increases at each BFR after 300 s exposure to (a) all frequencies with FPD = 125 mW/cm2 (varying \(\alpha\)) and (b) all frequencies with FPDs altered to maintain a constant power absorption of 75 mW/cm.2 (\(\alpha\) = 0.6)
Dnom ST increases at each BFR after 300 s exposure to (a) all frequencies with FPD = 125 mW/cm2 (varying \(\alpha\)) and (b) all frequencies with FPDs altered to maintain a constant power absorption of 75 mW/cm.2 (\(\alpha\) = 0.6)