“…Furthermore, there is a possibility of instability when H s < 0 and H t > 0 even if H s -f-H f < 0. The linear stability of a reactor with a two-temperature feedback path was also discussed by Bethe [18], Brittan [19], Ackroyd et al [20], and Little and Schultz [21], with different approaches. (See Problem 10 for another application.…”