Extracting the oscillatory component and defining a mean amplitude of thermokinetic oscillations in the H/Pd system

Abstract

The mean value theorem for integrals has been applied in constructing a base curve for non-equilibrium thermokinetic oscillations, q(t), recorded in oscillatory sorptions of H2(D2) in Pd. The mean values are calculated for each period of q(t), followed by cubic spline interpolation, forming the new non-oscillatory curve, h(t), to be used as a baseline for the oscillatory component of the original thermokinetic time series. Crucially, areas, under both q(t) and h(t) are strictly identical. Subsequent pointwise subtraction q(t) h(t) yields another oscillatory time series g(t), considered the oscillatory component extracted from the thermokinetic data. The method has been applied to various experimental time series q(t). Using the g(t) curves, a new parameter, the mean amplitude has been defined and used as a descriptor correlating the intensity of thermokinetic oscillations with various experimental conditions. The mean amplitude turns out to be a linear function of the first ionization potential of noble gases, admixed intentionally to H2 before its contacting Pd.