incorporating into said fluid a trisubstituted cyclic compound, of which the ring is substituted by one or two X—Am—Yn groups and wherein the remaining one or two substituents are —X Z groups, wherein {HEAD ~ the substituted ring} is {TAIL ~ a 1,3,5 substituted cyclohexane}, the compound being non symmetrical in that at least one of said —X Z groups is free of an Am moiety, wherein 
is
incorporating into said fluid a trisubstituted cyclic compound , of which the ring is substituted by one or two X — Am — Yn groups and wherein the remaining one or two substituents are — X Z groups , wherein { HEAD ~ the substituted ring } is { TAIL ~ a 1,3,5 substituted cyclohexane } , the compound being non symmetrical in that at least one of said — X Z groups is free of an Am moiety , wherein
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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL 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