659872.fig.005a
(a) Rotating speed (r.p.m.)
659872.fig.005b
(b) Rotating speed   (r.p.m.)
659872.fig.005c
(c) Rotating speed (r.p.m.)
659872.fig.005d
(d) Rotating speed (r.p.m.)
Figure 5: Effect of strength of electric field on the first three natural frequencies at different rotation speeds.