wherein {HEAD ~ the first plurality} of particles is mixed with {TAIL ~ a second plurality} of non encased particles, and 
is mixed with
wherein { HEAD ~ the first plurality } of particles is mixed with { TAIL ~ a second plurality } of non encased particles , and
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH