( ( Case hardening ) ( ( is ( ( a ( thermochemical ( diffusion process ) ) ) ( ( in which ) ( ( ( ( ( ( an ( alloying element ) ) , ) ( most commonly ) ) ( ( carbon or ) nitrogen ) ) , ) ( diffuses ( into ( ( the surface ) ( of ( a ( monolithic metal ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NN Case) (NN hardening)) (VP (VBZ is) (NP (NP (DT a) (JJ thermochemical) (NN diffusion) (NN process)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (NP (DT an) (JJ alloying) (NN element)) (, ,) (ADVP (RBS most) (RB commonly)) (NP (NN carbon) (CC or) (NN nitrogen)) (, ,)) (VP (VBZ diffuses) (PP (IN into) (NP (NP (DT the) (NN surface)) (PP (IN of) (NP (DT a) (JJ monolithic) (NN metal)))))))))) (. .)))
Case hardening is a thermochemical diffusion process in which an alloying element, most commonly carbon or nitrogen, diffuses into the surface of a monolithic metal.
(ROOT (S (NP (NNP Carbon)) (VP (VBZ is) (NP (NP (DT the) (ADJP (RBS most) (VBN found)) (NN element)) (PP (IN in) (NP (VBG living) (NNS organisms))))) (. .)))