DELAY EFFECTS AND DIFFERENTIAL DELAY EQUATIONS IN CHEMICAL-KINETICS

The effects of time lags on the kinetic behaviour of chemical systems are considered. Such lags can result from spatial separation of components of a system, from the introduction of a delayed feedback, or as a way of representing the effects of intermediate steps in a series of reactions. The mathematical apparatus for treating systems with delay is introduced. Then, a number of examples, both experimental and theoretical, are discussed. It is seen that time lags can produce major, qualitative changes in the behaviour of a system, and that it is sometimes possible to reduce significantly the number of variables needed to describe a system if one utilizes differential delay rather than ordinary differential equations.