We propose an alternative to the usual time–independent Born–Oppenheimer approximation that is specifically designed to describe molecules with non–symmetrical hydrogen bonds. In our approach, the masses of the hydrogen nuclei are scaled differently from those of the heavier nuclei, and we employ a specialized form for the electron energy level surface. As a result, the different vibrational mo...

In this paper we study the time evolution of fast MHD waves in a coronal loop driven by footpoint motions in linear ideal MHD. We restrict the analysis to footpoint motions polarized normal to the magnetic flux surfaces such that the fast waves are driven directly. By supposing the azimuthal wave number ky to be zero, the fast waves are decoupled from the Alfvén waves. As a first step to real s...

In a variety of applications in shallow water acoustics, coupled mode theory is an attractive model. In addition to the parabolic equation technique (PE), it is the only other numerically efficient model that provides the solution of the wave equation in a range-dependent environment. However, while the parabolic equation technique for propagation in the ocean over a bottom modeled as a fluid h...

SENSE MODE AND COUPLING IN A VIGILANCE TASK

We discuss the classical motion of a spring of arbitrary mass coupled to two arbitrary massive blocks attached at its ends. A general approach to the problem is presented and some general results are obtained. Examples for which a simple elastic function can be inferred are discussed and the normal modes and normal frequencies obtained. An approximation procedure to the evaluation of the normel...