Interaction Hamiltonians,spectral lineshapes and deviations from the exponential decay law at long times

Long-time deviations from the exponential decay law in atomic spontaneous emission are demonstrated to be unusually sensitive to the form of the interaction Hamiltonian used to describe the decay.     

The role of the interactive Kerr effect in two-photon optical multistability

We show that bistable behaviour in a two-photon resonant system within a cavity may be attributed to interactive mode-pulling via the two-photon optical Kerr effect and also to absorptive bleaching (atomic saturation). The interactive Kerr process may be regarded as giving rise to a new category of optical bistability. Moreover, a mechanism for the recently-predicted tristability can be found in terms of simultaneous competition between the interactive Kerr effect and bleaching.     

Vehicle Scheduling with Timed and Connected Calls: A Case Study

A manual method was developed for scheduling the vehicle fleet of a contract transport undertaking. The main requirements were observance of time limits on individual calls and the ability to allocate pairs or groups of related calls to the same vehicle. These objectives were achieved by introducing an initial allocation of calls to vehicles prior to sequential routing of the calls. The allocation was based on a model relating work density (calls per unit area) to vehicle loading (calls per unit of vehicle time), and on fact-finding research on the main parameters of calling time, travelling speed and distance. This relationship was embodied in a visual scheduling aid for use by the route planners. Implementation was successful and resulted in about 15 per cent of vehicle time being made available for additional revenue-earning work without increase in fleet size. When utilized this represented an effective saving in operating costs of about 12 per cent.     

NMR solvent shifts and structure elucidation in coumarins

The use of the solvent shift techniques enables the position of methyl, methoxyl and aromatic protons in coumarins to be determined and should prove a valuable aid to structural elucidation in this class of compounds.     

Theories whose resplendent models are homogeneous

Buechler proved that ifT satisfies certain conditions, then all resplendent models ofT are homogeneous. Here the theories whose resplendent models are all homogeneous are characterized as satisfying a pair of conditions (weaker than Buechler’s). It follows from the characterization that if all resplendent models ofT in some uncountable power are homogeneous, then all resplendent models ofT are homogeneous. The author thanks John Baldwin and the other participants in the 1979 and 1980 Forking Festivals for helping her to learn some stability, and especially, Steve Buechler, whose results led directly to the results of this paper. Research partially supported by the National Science Foundation under Grant MCS78-02224.     

The photochemistry of citral

Citral (I) is cyclized by UV irradiation¹ to 2-isopropenyl-5-methylcyclopentane-carboxaldehyde (II), containing the carbon skeleton of the monoterpenes of ants and catmint. 1,6,6-Trimethylbicyclo[2,1,1]hexane-2-carboxaldehyde (XII, R = H), produced in lesser amount at the same time, was synthesized from camphor. The two photocitrals may, perhaps, come from a common intermediate containing the cyclopentane ring.