کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1867056 | 1038153 | 2012 | 8 صفحه PDF | دانلود رایگان |
Through numerical simulation of the Hoff model we show that when ultrasound contrast agents (UCAs) are excited at frequencies which are close to integer (m>2m>2) multiples of their natural resonance frequency, the bifurcation structure of the UCA oscillations as a function of pressure may be characterized by 3 general distinct regions. The UCA behavior starts with initial period one oscillations which undergoes a saddle node bifurcation to m coexisting attractors for an acoustic pressure above a threshold, Pt1Pt1. Further increasing the pressure above a second threshold Pt2Pt2, is followed by a sudden transition to period 1 oscillations.
► Bifurcation structure of the ultrasound contrast agents at high frequencies has been classified.
► Frequencies were considered to be equal or close to m times the resonance of the system (m>2m>2).
► Above the 1st pressure threshold period 1 oscillations turn to period m via a saddle node bifurcation.
► Above the 2nd pressure threshold period m oscillations turn to period 1 via a saddle node bifurcation.
Journal: Physics Letters A - Volume 376, Issue 33, 2 July 2012, Pages 2222–2229