Izwana Idris

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We consider the problem of initiation of propagating waves in a one-dimensional excitable fiber. In the FitzHugh-Nagumo theory, the key role is played by "critical nucleus" and "critical pulse" solutions whose (center-) stable manifold is the threshold surface separating initial conditions leading to propagation and those leading to decay. We present(More)
We consider applications of a recently suggested new asymptotic approach to detailed ionic models of cardiac excitation. First, we describe a three-variable approximation for the excitation fronts in a detailed ionic model of human atrial kinetics. It predicts not only the speed of the fronts but also a condition for failure of propagation, i.e. gives an(More)
We consider the problem of initiation of a propagating wave in a one-dimensional excitable fibre. In the Zeldovich-Frank-Kamenetsky equation, a.k.a. Nagumo equation, the key role is played by the ldquocritical nucleusrdquo solution whose stable manifold is the threshold surface separating initial conditions leading to initiation of propagation and to decay.(More)
This paper focuses on the performance of polysulfone (PSf) and polyethersulfone (PES) ultrafiltration membranes with polyethylene glycol (PEG). The aim of this study is to determine the effect of PEG as an additive in producing PSf and PES membrane. The flat sheet membranes were prepared via a phase inversion method in which the casting dope solution(More)
We consider the problem of ignition of propagating waves in one-dimensional bistable or excitable systems by an instantaneous spatially extended stimulus. Earlier we proposed a method [I. Idris and V. N. Biktashev, Phys. Rev. Lett. 101, 244101 (2008)] for analytical description of the threshold conditions based on an approximation of the (center-)stable(More)
We consider the problem of initiation of a propagating wave in a one-dimensional bistable or excitable fiber. In the Zeldovich-Frank-Kamenetskii equation, also known as the Nagumo equation and Schlögl model, the key role is played by the "critical nucleus" solution whose stable manifold is the threshold surface separating initial conditions leading to the(More)
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