Convective Drying of Nonporous Biological Solids A $3mm$ bed of wet nonporous biological solids was dried in a tray by blowing air with $20\%$ relative humidity across the top of the bed at $70C$ and atmospheric pressure. The data in Table P$11\mathrm{.}5$ were obtained for the drying of these solids:

TABLE P $11\mathrm{.}5$

$\backslash$table$[[t(min),x_{m^{\text{'}}}$ mass water$/$mass dry solids$],[0,0\mathrm{.}190],[10,0\mathrm{.}176],[20,0\mathrm{.}153]]$

Drying $//439$

TABLE P$11\mathrm{.}5($Continued$)$

$\backslash$table$[[t(min),x_{m^{\text{'}}}$ mass water$/$mass dry solids$],[30,0\mathrm{.}130],[40,0\mathrm{.}107],[50,0\mathrm{.}084],[60,0\mathrm{.}064],[70,0\mathrm{.}050],[80,0\mathrm{.}039],[90,0\mathrm{.}031],[100,0\mathrm{.}026],[120,0\mathrm{.}018],[140,0\mathrm{.}014],[160,0\mathrm{.}012]]$

From the drying data, estimate the diffusion coefficient of water in the biological material and the heat transfer coefficient for the convective heat transfer. The wet material has a bulk density of $1\mathrm{.}1\frac{g}{c}{m}^3.$