Can a rate constant independent of sample size be obtained from the rate equation generally used in thermal analysis?

Some consequences of using the rate equation d/dt=k_tf() are shown on a simple example. It is demonstrated thatk_t usually depends on the sample size, and that it is usually incorrect to assume that if mass and heat transport effects are avoided both and d/dt — as functions of time — are independent of the initial mass. Rate equations should be based on real local quantities.