The modification of the Bel-Robinson type energy-momentum
  For describing the non-negative gravitational energy-momentum in terms of a pure Bel-Robinson type energy-momentum in a quasi-local 2-surface, both the Bel-Robinson tensor $B$ and tensor $V$ are suitable. We have found that this Bel-Robinson type energy-momentum can be modified such that it satisfies the Lorentz covariant, future pointing and non-spacelike properties. We find that these particular quasi-local energy-momentum properties can be obtained from (i): $B$ or $V$ plus a tensor $S$ in a small sphere limit, or (ii): directly evaluating the energy-momentum of $B$ or $V$ in a small ellipsoid region. (iii): calculate the total energy using the Landau-Lifshitz pseudotensor in a small ellipsoid, from Jupiter's tidal force to Io in Schwarzchild spacetime, in an elliptic orbit. 
Lau Loi So
gr-qc