  We investigate the behavior of a two dimensional array of Bose-Einstein
condensate tubes described by means of a Bose-Hubbard Hamiltonian. Using a
Wannier function expansion for the wavefunction in each tube, we compute the
Bose-Hubbard parameters related to two different longitudinal potentials,
periodic and quasiperiodic. We predict that - upon increasing the external
potential strength along the direction of the tubes - the condensate can
experience a reentrant transition between a Mott insulating phase and the
superfluid one.
