It has been found that {HEAD ~ CaX type adsorbents} provide {TAIL ~ the removal} of N2O and hydrocarbons in the third layer 
It has been found that { HEAD ~ CaX type adsorbents } provide { TAIL ~ the removal } of N2O and hydrocarbons in the third layer
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH