(a)–(c) Plots of versus time for the case of Model II and for different values of . Numerical integrations: Curve I, (2); Curve II, and . Direct numerical solutions: curve superposed to Curve I, ; Curve III, . (d) Plot of versus . Numerical methods: numerical values of the rest of the parameters and definition of are the same as in Figure 3. For each value of , the numerical value for the adjust factor (Appendix A) was obtained by trial and error in order to attain the best approximation to Curve I. The curve versus (d) was obtained as the best fit to a sample of values of for the corresponding values of , throughout the whole range of values of considered.
