Neste trabalho calcula-se o domínio de segurança relacionado ao lançamento de projéteis perto da superfície terrestre. Leva-se em consideração uma força de resistência proporcional à velocidade do projétil (regime laminar) e proporcional ao quadrado da velocidade (regime turbulento).

In this work we compute the safety domain related to projectiles fired close to the Earth's surface, taking into account a linear (laminar regime) and a quadratic drag force (turbulent regime).

We discuss the Casimir effect for a massive bosonic field with mixed (Dirichlet-Neumann) boundary conditions. We use the zeta-function regularization prescription to obtain our physical results. Particularly, we analyse how the Casimir energy varies with the mass of the field and compare this mass dependence with those obtained for other boundary conditions. This is done graphically. Some other graphs involving a massive fermionic field are also included.