Revisiting the Diffusion Problem in a Capillary Tube Geometry
  The present work revisits the problem of modeling diffusion above a stagnant liquid interface in a capillary tube geometry. In this revisitation we elucidate a misconception found in the classical model proposed by Bird et. al. Furthermore, we propose alternative explanations for thermally forced diffusion and provide a description of natural convection in the absence of forcing terms. 
Eric Sullivan and Lynn Schreyer-Bennethum
math-ph math.MP physics.flu-dyn