Find out the characteristic dimensions of three square cylindrical reactors; \(A, B\), and \(C\) with core diameter \(=3.5 \mathrm{~m}\). The other needed data of the reactors are given below in Table 7.8. The Diffusion Coefficient of reactors A, B, and C are \(1.22 \mathrm{~cm}, 1.50 \mathrm{~cm}\), and \(2.20 \mathrm{~cm}\), respectively. 

TABLE 7.8 Reactor 7 (cm) a (cm) A 29 0.065 (cm) 0.106 B 160 5.44 10-03 5.58 x 10-03 C 250 0.03522 0.05579