From the eighteenth century landowners had recognised the need for effective techniques for draining impermeable clay soils.
However, although the seed coat remained impermeable, and so imbibition was not possible, there appears to have been a response to the high external humidity.
The degree to which septate junctions may render a cell layer impermeable appears to be highly variable.
The theory has been applied to both impermeable and porous stationary and moving journal-bearing systems.
We investigate the propagation of the two fluid layers along a horizontal, impermeable boundary of a porous layer.
These shallow wells are apparently made possible by the presence of perched water tables that rest on impermeable geologic strata.
The chalaza, where the ovule was attached to the fruit, was the last portion of the seed to become impermeable.
Crudely speaking, the channel itself may be viewed as a pipe (cylinder) embedded in an impermeable membrane.
