  Gyratonic pp-waves are exact solutions of Einstein's equations that represent
non-linear gravitational waves endowed with angular momentum. We consider
gyratonic pp-waves that travel in the $z$ direction and whose time dependence
on the variable $u={1 \over \sqrt{2}}(z-t)$ is given by gaussians, so that the
waves represent short bursts of gravitational radiation propagating in the $z$
direction. We evaluate numerically the geodesics and velocities of free
particles in the space-time of these waves, and find that after the passage of
the waves both the kinetic energy and the angular momentum per unit mass of the
particles are changed. Therefore there is a transfer of energy and angular
momentum between the gravitational field and the free particles, so that the
final values of the energy and angular momentum of the free particles may be
smaller or larger in magnitude than the initial values.
