Finally, {HEAD ~ the protective coating} 13 is applied to {TAIL ~ the surface} of the filter as the last layer, and once again the peripheral region is kept free in order to form the contact bank 8 
is applied to
Finally , { HEAD ~ the protective coating } 13 is applied to { TAIL ~ the surface } of the filter as the last layer , and once again the peripheral region is kept free in order to form the contact bank 8
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL 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