3^He A-B Transition in Finite Geometries
  The measured rate of the 3^He A-B transition depends on the diameter of the experimental cell. Theoretically, this can only be explained by a direct drag on the interface exerted by the lateral walls, leading to a pressure discontinuity across the interface. This has not been considered before, either here or in similar circumstances. The general hydrodynamic theory that includes the influence of finite geometries is presented. 
Peter Kostaedt and Mario Liu