{HEAD ~ The surface area} of contact between the first and the second layers can define {TAIL ~ a frame} about the perimeter of the reservoir 
define
{ HEAD ~ The surface area } of contact between the first and the second layers can define { TAIL ~ a frame } about the perimeter of the reservoir
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH