An increase in {HEAD ~ zinc} from {TAIL ~ about 23%} to about 28 30% results in markedly higher electrical conductivity 
An increase in { HEAD ~ zinc } from { TAIL ~ about 23 % } to about 28 30 % results in markedly higher electrical conductivity
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH