OPTIMIZING COMPLEX KINETICS EXPERIMENTS USING LEAST-SQUARES METHODS

Complex kinetic problems are generally modeled employing numerical int egration routines. Our kinetics modeling program, Acuchem, has been mo dified to fit rate constants and absorption coefficients generically t o real or synthesized ''laboratory data'' via a least-squares iterativ e procedure written for personal computers. To test the model and meth od of analysis the self- and cross-combination reactions of HO2 and CH 3O2 radicals of importance in atmospheric chemistry are examined. Thes e radicals as well as other species absorb ultraviolet radiation. The resultant absorption signal is measured in the laboratory and compared with a modeled signal to obtain the best-fit to various kinetic param eters. The modified program generates synthetic data with added random noise. An analysis of the synthetic data leads to an optimization of the experimental design and best-values for certain rate constants and absorption coefficients.