  An oblique projections based feedback stabilizability result in the
literature is extended to a larger class of reaction-convection terms. A
discussion is presented including a comparison between explicit oblique
projections base feedback controls and Riccati based feedback controls.
Advantages and limitations of each type of feedback are addressed as well as
their finite-elements implementation. Results of numerical simulations are
presented comparing their stabilizing performances for the case of
time-periodic dynamics. It is shown that the solution of the periodic Riccati
based feedback can be computed iteratively.
