( Luminescence ( ( is ( emission ( of ( ( light ( by ( a substance ) ) ) ( not ( resulting ( from heat ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Luminescence)) (VP (VBZ is) (NP (NP (NN emission)) (PP (IN of) (S (NP (NP (NN light)) (PP (IN by) (NP (DT a) (NN substance)))) (RB not) (VP (VBG resulting) (PP (IN from) (NP (NN heat)))))))) (. .)))
Luminescence is emission of light by a substance not resulting from heat.
(ROOT (S (NP (NP (NNP Producing) (NN light)) (PP (IN without) (NP (NN heat)))) (VP (VBZ is) (VP (VBN called) (S (ADJP (JJ luminescence))))) (. .)))