“…Let Γ t be given by a rotation of the graph of a function y = u(x, t) (defined on x ∈ R) around the x-axis (cf [1,2]). In our previous paper [4], among other results, we have proved that if u(x, 0) → m := inf x∈R u(x, 0) > 0 as |x| → ∞, then Γ t closes open ends at the time T (m), where T (m) is the quenching (pinching) time of the regular cylinder with radius m. (Moreover, there is no neck-pinch in R at t = T (m).) These results imply that lim x→∞ u(x, T (m)) = 0 or lim x→−∞ u(x, T (m)) = 0, but it does not provide the convergence rate.…”