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