( Sometimes ( , ( ( ( ( the rate ) ( of dissipation ) ) ( -LRB- ( or ( ( ( any ( other ( decay process ) ) ) ( that ( behaves ( like this ) ) ) ) -RRB- ) ) ) ) ( ( is ( described ( in ( terms ( of ( ( ( its half-life ) , ) ( ( the time ) ( it ( ( takes ( for ( half ( of ( the amount ) ) ) ) ) ( to decay ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Sometimes)) (, ,) (NP (NP (NP (DT the) (NN rate)) (PP (IN of) (NP (NN dissipation)))) (PRN (-LRB- -LRB-) (CC or) (NP (NP (DT any) (JJ other) (NN decay) (NN process)) (SBAR (WHNP (WDT that)) (S (VP (VBZ behaves) (PP (IN like) (NP (DT this))))))) (-RRB- -RRB-))) (VP (VBZ is) (VP (VBN described) (PP (IN in) (NP (NP (NNS terms)) (PP (IN of) (NP (NP (PRP$ its) (NN half-life)) (, ,) (NP (NP (DT the) (NN time)) (SBAR (S (NP (PRP it)) (VP (VBZ takes) (PP (IN for) (NP (NP (NN half)) (PP (IN of) (NP (DT the) (NN amount))))) (PP (TO to) (NP (NN decay))))))))))))) (. .)))
Sometimes, the rate of dissipation (or any other decay process that behaves like this) is described in terms of its half-life , the time it takes for half of the amount to decay.
(ROOT (S (NP (DT The) (NN term) (NN half-life)) (VP (VBZ decribes) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN time)) (VP (VBN required) (PP (IN for) (NP (NP (NN half)) (PP (IN of) (NP (DT the) (JJ original) (NN material))))) (PP (TO to) (NP (NP (NN decay)) (PP (IN in) (NP (DT an) (NN isotope)))))))))) (. .)))