where 0<x<1, 0.6≦y≦1.1 and 0.05≦d≦0.05, {HEAD ~ x} representing {TAIL ~ a weight fraction} 
where 0 < x<1 , 0.6≦y≦1.1 and 0.05≦d≦0.05 , { HEAD ~ x } representing { TAIL ~ a weight fraction }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL