Air flowing through a tube of 75-mm diameter passes over a 150-mm-Iong roughened section that is constructed from naphthalene having the properties M = 128.16 kg/kmol and psat(300 K) = 1.31 x 10-4 bar. The air is at 1 atm and 300 K, and the Reynolds number is ReD = 35,000. In an experiment for which flow was maintained for 3 h, mass loss due to sublimation from the roughened surface was determined to be 0.0 I kg. What is the associated convection mass transfer coefficient? What would be the corresponding convection heat transfer coefficient? Contrast these results with those predicted by conventional smooth tube correlations.