The melting point of a polymer containing lamellae of thickness L is given by Tm (K) = T (1 2y/LAH), where Tm is the melting point of the infinitely thick crystal, ys is the specific free energy of the lamellar surface, and AH, is the enthalpy of fusion per unit volume. Calculate Tm for polyethylene containing lamellae 12.0 nm thick. Take Tn = 416.7 K, y = 0.0874 Jm-2, and AH = 279 MJ m - 3 =