A simple activated carbon air filter is useful to remove strong odours or harmful gases at home (room temperature at 30C and the air viscosity is 0.02mPa.s). If the air filter is a cylindrical tube fully packed with small carbon particles (approximately 1mm diameter with density of 1.2g/cm3 ), calculate the air linear circulation velocity and the specific surface of the bed if pressure drop of 0.1atm is expected (Let R=0.082atm.m3/kmol.K ). Given that the air filter is 145cm height and 18cm diameter, and the total mass of the carbon particles is approximately 7800g. [34 marks]