Salt free cheddar cheese in wheel shape is dipped into the brine solutioncontaining $20\%$ salt during the salting process where salt diffuses in the cheese. Cheesehas a diameter of $12$ cm and a thickness of $5$ cm$.$ The diffusivity of salt in the cheese is$0\mathrm{.}33$ x $10-9$ m$2/$s$.$ If convective mass transfer coefficient of the system is given as $2$ x $10-7$m$/$s$,$ determine the leading transport direction and calculate the required processingtime to obtain $12\mathrm{.}8\%$ salt concentration at the center of the cheddar cheese.