Klymenko O. Mathematical and computer modelling of photochemical processes and determination of their kinetic parameters

The research subject comprises homogeneous chemical reactions represented by stoichiometric equation systems and photochemical experimental data. The research objective is the mathematical and computer modelling of homogeneous chemical processes and the determination of unknown values of key parameters of a photochemical experiment. Numerical methods for ODEs and numerical minimisation methods have been utilised. Theoretical results of this study include the approaches for the a priori determination of stiffness of a Cauchy problem and the determination of the necessary local error limit of the applied numerical ODE solver. A practical result is the developed software "KinFitSim". The scientific novelty of this study is: 1) the generalised mathematical model of a homogeneous chemical process in the form of a Cauchy problem for an ODE system; 2) the approach for the determination of the local error limit of a numerical ODE solver that provides physically meaningful numerical solutions; 3) the criterionfor determining the stiffness of a given Cauchy problem from initial data; 4) the approach to parameter identification utilising simultaneously several datasets; 5) the software "KinFitSim" which allows modelling homogeneous chemical reactions and identification of their parameters. "KinFitSim" is being used in 5 major scientific institutions worldwide. The results of this study may be applied to the solution of various physicochemical and biochemical problems involving homogeneous chemical processes.