Ab initio molecular orbital calculations on t h e intramolecular rearrangements of t h e methylperoxyl and ethylperoxyl radicals are reported, together with transition-state structures and vibration frequencies for t h e ethylperoxyl reactions. Estimated equilibrium constants for t h e formation of two methylperoxyl isomers, CH(OH), and CH,(OH)O, are also reported.

A numerical study of the vibrational relaxation at 500 K of a mixture of ortho-H, and para-H, is described. The required state-to-state rate constants were calculated from the quantum results of Rabitz and co-workers, and missing pieces of data were estimated by interpolation.It is concluded that only one relaxation time will be observed in any mixture of ortho-H, and para-H, and that (except at very high dilutions in a third inert gas) the relaxation rate constant will be close to the mean of the individual rate constants for relaxation, weighted according to the respective mole fractions of ortho-Hz and para-H, present in the mixture.We find that the relaxation process can be modelled very accurately as an electrical RC network, whose time constants can be written down quite easily as sums of the appropriate microscopic rate constants, and by using this model, it is a simple matter to explore the conditions required for a mixture of two gases to exhibit two distinct vibrational relaxation times. On conclut qu'un seul temps de relaxation pourra btre observe pour tous les melanges de H, ortho et para et que (B ['exception des cas de tres fortes dilutions dans un troisieme gaz inerte), la constante de vitesse de relaxation sera voisine de la moyenne des constantes individuelles des vitesses de relaxation ponderees selon les fractions molaires respectives de Hz ortho et para presentes dans le melange. [Traduit par le journal]

The E Region Wind INterferometer (ERWIN) was designed specifically to measure winds in the cold (200 K) region of the earth’s atmosphere near the mesopause (85–100 km altitude) by detecting the Doppler shifts of the faint airglow emissions occuring there.

AVYGDOR Mom and Huw 0. PRITCHARD. Can. J. Chem. 67, 442 (1989).The Newton method was shown by Vatsya to be suitable for solving the generalised elliptic problem, and we show that this approach can be used to treat the Frank-Kamenetskii model of a thermal explosion, by using a variational solution of the sequence of linear equations that are encountered in the Newton method. Convergence to the desired solution is rapid in the case of spherical geometry. The method produces converging upper and lower bounds to the critical value of the dimensionless heat production rate, ?I,, and lower bounds to the dimensionless temperature excess distribution function 0 and its critical form 0,.

This RFC provides a framework for transporting ANSI C12.22/IEEE 1703/MC12.22 Advanced Metering Infrastructure (AMI) Application Layer Messages on an IP network.This document is not an official submission on behalf of the ANSI C12.19 and C12.22 working groups. It was created by participants in those groups, building on knowledge of several proprietary C12.22-over-IP implementations.