Two types of transient responses have been investigated in fly motion-sensitive neurons in the past: the impulse and the step response. In response to a brief motion pulse, cells show a sudden rise in activity followed by an exponential decay ('impulse response'). In response to the onset of a constant velocity stimulus, cells exhibit transient oscillations before settling to a steady-state val...

In this paper, exact solutions of velocity and stresses are obtained for the magnetohydrodynamic (MHD) flow of a Maxwell fluid in a porous half space by the Laplace transform method. The flows are caused by the cosine and sine oscillations of a plate. The derived steady and transient solutions satisfy the involved differential equations and the given conditions. Graphs for steady-state and tran...

We consider an HIV pathogenesis model incorporating antiretroviral therapy and HIV replication time. We investigate the existence and stability of equilibria, as well as Hopf bifurcations to sustained oscillations when drug efficacy is less than 100%. We derive sufficient conditions for the global asymptotic stability of the uninfected steady state. We show that time delay has no effect on the ...

In [1] the occurence of a Hopf bifurcation at steady-state cornering for two-wheel oversteering vehicle with brush model tyre forces was found and following bifurcating branch periodic solutions we observed Canard phenomenon relaxation oscillations, which are typical singularly perturbed systems. that article assumed simplicity, car's center mass lies street level. this presentation investigate...

The electroretinogram (ERG) evoked in the lobster by a short flash of light consists of a highly damped, slow oscillation of potential, triggered apparently by a single excitatory process. Near the threshold, only one wave may be evident; but as the intensity of stimulus rises, a prior wave appears, and grows so much more rapidly as to become dominant. Simultaneously third and later waves appea...

Start-up times in viscoelastic channel and pipe flows generated by the sudden imposition of a pressure gradient are here determined by a mixed analytical/numerical procedure. The rheological models considered are the upper convected Maxwell and the Oldroyd-B equations. With these models the flow evolves asymptotically to the steady state solution after a transient regime presenting strong oscil...

We present an experimental and numerical study of the chlorine dioxide-iodide (CDI) reaction in a single, well-stirred, flow-through reactor with feedback regulation of flow rate in three different arrangements. The control is accomplished through a computer-mediated sigmoidal dependence of the dynamic flow rate(s) on the iodide concentration. Numerical simulations predict interesting dynamics ...

A chemostat limited by a single growth-limiting substrate displays a rich spectrum of dynamics. Depending on the flow rate and feed concentration, the chemostat settles into a steady state or executes sustained oscillations. The transients in response to abrupt increases in the flow rate or the feed concentration are also quite complex. For example, if the increase in the flow rate is small, th...

We investigate the behavior of a system composed of two small identical water droplets loaded with an activator-inhibitor system possessing only a single stable steady state and coupled through a third, ‘‘signaling’’ species able to diffuse through the interdroplet medium. Depending on whether the third species is coupled to the activator or the inhibitor, the system can exhibit wave instabilit...