( ( ( Nitrogen ( oxides-or NOx ) ) ( for ( short - ) ) ) ( ( are ( formed ( at ( ( high ( temperature combustion ) ) ( when ( ( nitrogen ( in ( ( ( the air ) ( -LRB- ( ( which ( ( is otherwise ) ( generally ( inert ( in ( the atmosphere ) ) ) ) ) ) -RRB- ) ) ) ( ( along ( with ( nitrogen ( in ( the material ) ) ) ) ) ( being burned ) ) ) ) ) ( reacts ( with oxygen ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Nitrogen) (NNP oxides-or) (NNP NOx)) (PP (IN for) (NP (JJ short) (NNS -)))) (VP (VBP are) (VP (VBN formed) (PP (IN at) (NP (NP (JJ high) (NN temperature) (NN combustion)) (SBAR (WHADVP (WRB when)) (S (NP (NP (NN nitrogen)) (PP (IN in) (NP (NP (DT the) (NN air)) (PRN (-LRB- -LRB-) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (ADVP (RB otherwise)) (ADJP (RB generally) (JJ inert) (PP (IN in) (NP (DT the) (NN atmosphere))))))) (-RRB- -RRB-)) (VP (ADVP (IN along) (PP (IN with) (NP (NP (NN nitrogen)) (PP (IN in) (NP (DT the) (NN material)))))) (VBG being) (VP (VBN burned)))))) (VP (VBZ reacts) (PP (IN with) (NP (NN oxygen)))))))))) (. .)))
Nitrogen oxides-or NOx for short -are formed at high temperature combustion when nitrogen in the  air (which is otherwise generally inert in the atmosphere) along with nitrogen in the material being burned reacts with oxygen.
(ROOT (S (NP (NNP Nitrogen)) (VP (VBZ oxide) (NP (NP (NN form)) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-)) (SBAR (WHADVP (WRB when)) (S (NP (NN nitrogen) (CC and) (NN oxygen)) (VP (VBP combine) (PP (IN at) (NP (JJ high) (NNS temperatures)))))))) (. .)))