( ( As ( cooling ( agent liquid ) ) ) ( ( ( ( helium ( as ( well as ) ) ) liquid ) nitrogen ) ( ( can ( be used ) ) . ) ) )
(ROOT (S (PP (IN As) (S (VP (VBG cooling) (NP (NN agent) (NN liquid))))) (NP (ADJP (NN helium) (CONJP (RB as) (RB well) (IN as)) (JJ liquid)) (NN nitrogen)) (VP (MD can) (VP (VB be) (VP (VBN used)))) (. .)))
As cooling agent liquid helium as well as liquid nitrogen can be used.
(ROOT (S (NP (NN Liquid) (NN nitrogen)) (VP (VBZ is) (VP (VBN used) (PP (IN for) (NP (NP (VBG cooling) (NNS detectors)) (PP (IN of) (NP (JJ infrared) (NNS telescopes))))))) (. .)))