title: Intrinsic periodic and aperiodic stochastic resonance in an electrochemical cell.
abstract: In this paper we show the interaction of a composite of a periodic or aperiodic signal and intrinsic electrochemical noise with the nonlinear dynamics of an electrochemical cell configured to study the corrosion of iron in an acidic media. The anodic voltage setpoint (V_{0}) in the cell is chosen such that the anodic current (I) exhibits excitable fixed point behavior in the absence of noise. The subthreshold periodic (aperiodic) signal consists of a train of rectangular pulses with a fixed amplitude and width, separated by regular (irregular) time intervals. The irregular time intervals chosen are of deterministic and stochastic origins. The amplitude of the intrinsic internal noise, regulated by the concentration of chloride ions, is then monotonically increased, and the provoked dynamics are analyzed. The signal to noise ratio and the cross-correlation coefficient versus the chloride ions' concentration curves have a unimodal shape indicating the emergence of an intrinsic periodic or aperiodic stochastic resonance. The abscissa for the maxima of these unimodal curves correspond to the optimum value of intrinsic noise where maximum regularity of the invoked dynamics is observed. In the particular case of the intrinsic periodic stochastic resonance, the scanning electron microscope images for the electrode metal surfaces are shown for certain values of chloride ions' concentrations. These images, qualitatively, corroborate the emergence of order as a result of the interaction between the nonlinear dynamics and the composite signal.
authors.affiliation: Department of Physics, Indian Institute of Technology, Bombay, Powai, Mumbai-400 076, India.
authors.forename: Ishant
authors.initials: I
authors.lastname: Tiwari
authors.affiliation: Department of Physics, Indian Institute of Technology, Bombay, Powai, Mumbai-400 076, India.
authors.forename: Richa
authors.initials: R
authors.lastname: Phogat
authors.affiliation: Department of Physics, Indian Institute of Technology, Bombay, Powai, Mumbai-400 076, India.
authors.forename: P
authors.initials: P
authors.lastname: Parmananda
authors.affiliation: Centro de Investigación en Ciencias-(IICBA), UAEM, Avenida Universidad 1001, 62209 Cuernavaca, Morelos, México.
authors.forename: J L
authors.initials: JL
authors.lastname: Ocampo-Espindola
authors.affiliation: Centro de Investigación en Ciencias-(IICBA), UAEM, Avenida Universidad 1001, 62209 Cuernavaca, Morelos, México.
authors.forename: M
authors.initials: M
authors.lastname: Rivera