New experiments for a systematic approach to the determination of the reaction mechanisms of an oscillatory combustion reaction and an oscillatory enzymatic reaction.

摘要

Experimental and theoretical studies are reported on two oscillatory reactions: the oxidation of acetaldehyde in a flow reactor and the horseradish peroxidase catalyzed oxidation of NADH in a semi-batch reactor. Experimental tests are designed to provide information useful in formulating a reaction mechanism. Measured in this thesis are the relative amplitude of oscillation, the relative phase of oscillation, the quench vector amplitude and phase, the regulation of several species in response to a step perturbation of one species, and the total change in phase shift across the entrainment band for a sinusoidal variation of the concentration of one species. These quantities are calculated with two models for the acetaldehyde oxidation reaction. Experimental quantities are measured by mass spectrometry (acetaldehyde reaction) and by spectrophotometry and an oxygen electrode (horseradish peroxidase reaction). Comments are provided concerning the utility of the tests employed in this thesis.;In the acetaldehyde oxidation reaction, the species acetaldehyde, oxygen, methane, water, carbon dioxide, hydrogen peroxide, methanol, and formaldehyde are observed to have small relative amplitudes and so found to be nonessential. The results of the calculations with two models for oscillatory cool flames indicate that the essential variables in the model systems are internal temperature, one short-lived species, and several radicals. Both models are Category 2 oscillators in Eiswirth's classification scheme.;The concentration shift regulation of eight species was measured for step perturbations of acetaldehyde and oxygen; the results agree with the calculations made with two models except for the responses of carbon dioxide and water due to a step perturbation in acetaldehyde. The concentration shift regulation of nine species for a step change in internal temperature was inferred from data found in the literature; there is partial agreement between these results and model predictions. The relative phase of oscillation measured for the eight species compares well to the calculations for most species.;In the horseradish peroxidase reaction, the oscillations were successfully quenched with a pulse-like addition of oxygen, indicating that the quench vector amplitude is finite and that oxygen is an essential variable. The quench vector phase is 99