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Description:
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state model to the case of OH addition to isoprene . Excellent agreement with observed
temperature and pressure dependent rate constants affords a high confidence level in
understanding of the kinetics and in the calculated branching ratio of the initial OH
addition step .
I then focus attention on the subsequent reactivity of the OH -isoprene adducts .
Until recently , all four of the OH -isoprene adducts were supposed to have reacted with
O2 via addition to form alkylperoxy radicals . Previous computational results suggest that
two of the OH -isoprene adducts undergo an intramolecular cyclic isomerization
followed by hydrogen abstraction by O2 to form stable carbonyl compounds . I have
synthesized photolytic precursors , presenting a novel approach to probe the subsequent
reactivity of individual hydroxyalkyl radicals .
Initial verification of the cyclic isomerization pathway involved synthesis of the
photolytic precursor corresponding to the 1 ,3 -butadiene -OH adduct . A culmination of
theoretical and experimental techniques allowed verification of the cyclic isomerization
pathway . I synthesized the photolytic precursor , which provided a single isoprene -OH
adduct . Employing laser photolysis /laser induced fluorescence , time -dependent
multiplexed mass spectrometry , velocity map ion imaging , and theoretical techniques ,
we present the full characterization of the reactivity of the single isoprene -OH adduct in
the presence of O2 . Bureau of Economic Research (NBER ) production data , and outsourcing data provided
by Feenstra and Hanson , I find that outsourcing decreased blue -collar laborers’ average
years of completed education ; increased the hiring of females into white -collar workers ,
and increased job stability of unskilled and skilled laborers in the 1980s . Thus ,
outsourcing did not take away unskilled laborers’ jobs but hindered new hiring of young
unskilled workers . |