Richard W. Rothery

Line intensities in vibration-rotation bands of diatomic molecules

Abstract The expression for the transition probability for a rotating Morse or Pekeris oscillator obtained by Herman and Rubin has been simplified considerably for numerical calculation. The details of the simplification are presented. In its reduced form, the transition probability consists of the product of the transition probability of a non-rotating Morse oscillator obtained by Heaps and Herzberg and a rotational correction factor which is termed the F -factor. We have calculated F -factors for the 1-0, 2-1, 2-0, and 3-0 vibration-rotation bands of HF, HCl, and CO. The F -factors for the fundamental band of a rotating Morse oscillator are shown to be in excellent agreement with the corresponding F -factors for a rotating anharmonic oscillator obtained by Herman and Wallis.

The Synchronization of Traffic Signals for Minimum Delay

In order to ascertain whether neighboring intersections can be effectively coupled on the basis of traffic behavior, observational information on vehicular platoons was collected at four sites in London, England. This information is analyzed with particular emphasis on the phasing or synchronization of neighboring intersections for minimum delay. At each of the four sites studied, arrival time data was collected at four positions downstream from the signalized intersection from which the vehicular platoons were emerging. This data gives a measure of how platoons diffuse as they move from one intersection to the next. The analysis indicates that the diffusion process can be taken into account in the setting of signals. In particular, total delay in vehicle-hours per hour of green as a function of offset time is calculated, and in turn, the optimal offset time that would minimize delay is shown to be a linear function of the distance from the issuing traffic signal.