Hi vel low P Gas transport Low vel, hi P Laminar flow across plate Transport Hi vel. low acrosS boundary ∝D△C Plate Knudsen Nk Viscous flow 2 Tube Wall Laminar flow pipe Conductance aA/L Mon., Sept. 15, 2003Gas transport J1 µDgDC Transport across boundary layer 2 Knudsen NK ≡ lL <1 L Viscous flow Dgas ª lvx 2 Mon., Sept. 15, 2003 5