  In this note we discuss two aspects of screw dislocations dynamics: their
behavior near the boundary and a way to confine them inside the material. In
the former case, we obtain analytical results on the estimates of collision
times (one dislocation with the boundary and two dislocations with opposite
Burgers vectors with each other); numerical evidence is also provided. In the
latter, we obtain analytical results stating that, under imposing a certain
type of boundary conditions, it is energetically favorable for dislocations to
remain confined inside the domain.
