Engineering topics
Publications and source records attributed to Margitan, J. J..
An evaluated set of rate constants and photochemical cross sections were compiled for use in modelling stratospheric processes. The data are primarily relevant to the ozone layer, and its possible perturbation by anthropogenic activities. The evaluation is current to, approximately, January, 1979.
Three simultaneous observations of atomic chlorine (Cl) and the clorine monoxide radical (ClO) are reported which encompass the altitude interval between 25 and 45 kilometers. Together, Cl and ClO form a gas-phase catalytic cycle potentially capable of depleting stratospheric ozone. Observed Cl and ClO densities, although variable, imply that chlorine compounds constitute an important part of the stratospheric ozone budget. The results are compared with recent models of stratospheric photochemistry which have been used as a basis for predicting ozone depletion resulting from fluorocarbon release.
The reaction of OH radicals with D-atoms to form OD has been studied at room temperature in a discharge-flow system utilizing UV resonance fluorescence detection of the molecular species. A rate constant of approximately 1.3 by 10 to the -10th power cu cm per sec is reported where the error limits include systematic error estimates. Astrophysical and kinetic implications are discussed briefly.
The reaction OH + HN3 yields H2O + NO3 was studied over the temperature range 270-470 K in a flow system utilizing UV resonance fluorescence detection of OH. A temperature independent rate constant of (8.9 plus or minus 1.3) x 10 to the -14 cu cm/s was obtained, where the reported uncertainty represents a single standard deviation including estimates of systematic errors.