ABSTRACT
A medium or a medium boundary movement also gives rise to
various important non-stationary phenomena in addition to the
changes in material properties discussed in the previous chapter.
Apart from the classical uniform movement of a medium or its
boundaries other forms of movement are of interest [1, 2]. Rota-
tional movement has been investigated most often. It leads to the
scattering [3-9] and amplification [10, 11] of electromagnetic waves
and to the appearance of peculiar effects of ponderomotive forces
[12, 13]. The modulation and transformation of the electromagnetic
spectrum of waves being reflected from vibrating surfaces have also
been investigated [14-17]. Nevertheless, uniform movement is also
interesting due to a whole series of new problems concerned with
a complex form of moving boundaries [2, 18] or with the radiation
of sources crossing through moving complex boundary [19, 20].
There are also some more fundamental problems. The problem of
“paradoxes” of moving boundaries [21-23] can be chosen among
them. These paradoxes occur because of the discrepancy between a
number of secondary waves and a number of boundary conditions.
In order to resolve these paradoxes it is proposed in [21] to abandon
a sharp boundary idealisation and to consider a structure with
a boundary transition layer. However, it will be shown in this
chapter that the Volterra integral equation approach allows these
“paradoxes” to be resolved whilst retaining these sharp boundaries.
