Sequential coupling

Abstract: The purpose of this paper is to present a numerical simulation of the behavior of a sphere-plane electrical contact when a high current flows through it. A sequential coupling allows to study the interactions between mechanical, electrical and thermal phenomena occurring under a high current flow (intensity between 20 and 60 kA). The structural deformations and the voltage and temperature distributions are computed with the help of the finite element method via the ANSYS software. The 2D axisymmetric geometry considers a smooth sphere pressed on a smooth plane. The model takes into account the temperature dependency of material properties such as Young's modulus, hardness, electrical and thermal conductivities, specific heat, and coefficient of thermal expansion. The influence of the current intensity, the contact force, and the duration of the current flow on the potential distribution has been studied. As they are coupled, all phenomena are affected by heat generation variations and every phenomenon has an effect on all others and so on. In some particular conditions, analytical calculations make it possible to validate the simulation. Comparisons with experimental results are realized with several contact forces.

Abstract: An arrangement for the noninvasive coupling of information from a plurality of devices, including sensors, to an optical fiber at different locations uses a photodetector and a fiber bender attached to each device in such a manner that the sequential transmission of trigger signals to the photodetector of each device causes the sequential coupling of the information to the optical fiber by the fiber bender.

Abstract: In this paper, we propose and solve sequential coupling models for molecular dissociation of the Rice‐McLaughlin‐Jortner (RMJ) type in which the usual assumption of constant coupling among the states is replaced by an assumption of random coupling. The counter‐intuitive nonsequential branching behavior found previously for constant coupling is eliminated and we find completely sequential time dependence which obeys the phenomenological rate equations. We isolate the features of constant vs random coupling which give rise to the branching vs sequential behavior in terms of simple physical models and considerations of the coherence properties of the wavefunction. It is concluded that constant coupling is inappropriate for most molecules, and that the random coupling assumption has the effect of validating the use of a random phase approximation which in turn causes the molecule to decay as if each quasibound molecular level is coupled to its own continuum. Our conclusions do not change when we solve an extended model with many continua, with each molecular level coupled to each continuum.