{TAIL ~ A small hole} is formed within each portion of the exposed membrane so that a differential pressure can be applied across the membrane without collapsing the membrane pores while effecting {HEAD ~ passage} of liquid through the membrane 
{ TAIL ~ A small hole } is formed within each portion of the exposed membrane so that a differential pressure can be applied across the membrane without collapsing the membrane pores while effecting { HEAD ~ passage } of liquid through the membrane
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH