1. (20 Points) A flat slab of wood 50 mm thick containing 90 mol/m3 moisture is being dried from the top surface by passing hot dry air. The equilibrium moisture content at the surface of the wood due to the drying air blown over it is held at 6.6 mol/m3 moisture. The drying can be assumed to be represented by diffusivity of 8.0 x 10-6 m/h. a) What is the moisture content at a point 1.4 cm beneath the slab surface after 24 h? b) What is the required time for the moisture content at the slab center to reach 50 mol/m3? X