Date of Graduation
1988
Document Type
Dissertation/Thesis
Abstract
This work reports on three projects undertaken with the aim of learning more about complex behavior such as multiple steady states in a CSTR and traveling waves and spatial structures in unstirred solutions. Bistability in the permanganate-oxalate system was studied spectrophotometrically and computationally using a CSTR in a UV-Vis spectrophotometer. Absorbance of the solution was monitored as a function of flow rate. The concentrations of several manganese containing species in each of the steady states at a specific flow rate were determined using multi-component analysis. A four-variable empirical rate law model and computational results were presented. An experimental investigation of relaxation behavior in the bistable iodate-arsenous acid system revealed a region of flow rates where the system exhibited an apparent metastable steady state. Since this state appears as a plateau in a plot of iodide concentration vs. time, the region is called the plateau region. Relaxation times were measured and the limits of the plateau region determined. The relaxations have the form {dollar}\au{dollar} = c(k{dollar}\\sb{lcub}0{rcub})\\sp{lcub}\\rm -z{rcub}{dollar}, where c is a constant, z is the critical exponent, k{dollar}\\sb{lcub}0{rcub}{dollar} = {dollar}\\vert\\rm k\\sb{lcub}0{rcub} - k\\sbsp{lcub}0{rcub}{lcub}\\rm t{rcub} \\vert{dollar}, and k{dollar}\\sbsp{lcub}0{rcub}{lcub}\\rm t{rcub}{dollar} is the reciprocal residence time of the transition point. The experimental value of the critical exponent was evaluated. Relaxation times and the value of the critical exponent were determined using both a numerical integration method and an analytical solution of a simple one-variable model of the iodate-arsenous acid system. The experimental and computational results were found to be in good agreement. The development of a two-dimensional spectrophotometer for the study of chemical waves and spatial structures was described. The system was applied to the Belousov-Zhabotinskii reaction using an immobilized ferroin catalyst. Broken spirals and spatial turbulence were discovered and characterized.
Recommended Citation
Reckley, John Steven, "Studies of nonlinear dynamics in chemical systems." (1988). Graduate Theses, Dissertations, and Problem Reports. 9628.
https://researchrepository.wvu.edu/etd/9628