  We calculate the charge and heat current associate with electrons, generated
by a temperature gradient and chemical potential difference between two ends of
a tubular nanowire of 30 nm radius in the presence of an external magnetic
field perpendicular to its axis. We consider a nanowire based on a
semiconductor material, and use the Landauer-Bttiker approach to calculate the
transport quantities. We obtain the variation of the Seebeck coefficient ($S$),
thermal conductivity kappa, and the figure of merit ($ZT$), with respect to the
temperature up to 20\,K, and with the magnetic field up to 3 T. In particular
we show that the Seebeck coefficient can change sign in this domain of
parameters. In addition $\kappa$ and $ZT$ have oscillations when the magnetic
field increases. These oscillations are determined by the energy spectrum of
the electrons.
