Perturbation studies of excitable media

Lisa Elizabeth Seagraves, West Virginia University


Poly(N-isopropylacrylamide) (PNIPA) based systems are probably the most often studied polymer gels due to their dramatic change in volume, swelling and deswelling. Since this system has the best response to pH between 4 and 7, the ferrocyanide-iodate-sulfite (FIS) reaction, which exhibits pH oscillations between 4 and 7.5 in a continuously stirred tank reactor (CSTR), is a good candidate for studies of oscillatory gel systems.;This work also focused on two dynamical phenomena in the ruthenium catalyzed Belousov-Zhabotinsky (BZ) reaction. One is self-organized criticality and the other is periodic forcing and how they can be studied with the BZ reaction. Self-organized criticality is the ability of a system to organize itself into a critical state as a response to random perturbations. Periodic forcing gives rise to waves being sustained in a subexcitable medium by imposing periodic perturbations above and below the excitability limit.