The mating behaviour of tsessebe was observed in the Kruger National Park. A description of the typical sequences in the mating behaviour is given which includes the "nose and neck stretch" posture of the courtship display of the bull when approaching a cow, the role of olfactory stimuli which are derived from either smelling at the base of a cow's tail or… (More)

In this paper we consider a model of an N-stepped bar. It is assumed that the longitudinal vibrations in each section of the thick bar is described by a fourth order Rayleigh equation. The analytical tools of vibration analysis are based on finding eigenfunctions with piecewise continuous derivatives, which are orthogonal with respect, to a specially chosen… (More)

"Bryan's effect" - that is, the effect of a vibrating pattern's precession in the direction of inertial rotation of a vibrating ring - was discovered by G. Bryan in 1890. This effect has several applications in navigational instruments, such as cylindrical, hemispherical and planar circular disc rotational sensors. The model of a thin circular disc… (More)

In this paper we consider the Dirichlet and diffraction problems for parameter-elliptic pseudo-differential operators. The present paper shows that, the regularisator (exact solution) to the Dirichlet problem can be obtained as a limit of the regularisator of the corresponding diffraction problem