Magnetic Alignment Process : A New Mechanism for Extracting Energy from   Rotating Black Holes
  As a complementary or companion process to the Blandford-Znajek mechanism for the rotational energy extraction from a Kerr black hole to serve as a viable model for the central engine of quasar, AGN and even GRB, the magnetic alignment process is proposed. In contrast to the environment assumed in the Blandford-Znajek mechanism in which the rotating hole's spin axis and the asymptotic direction of the magnetic field are aligned, this new process operates when they are generally misaligned which obviously is the more natural situation likely to happen. The time scales over which these two processes take place and the total radiated powers released at the horizon by them have been estimated and found to be nearly comparable. This may imply that in a random, non-axisymmetric configuration, the magnetic alignment process would operate first during which some of the hole's rotational energy is released and upon completion of the alignment, the Blandford-Znajek mechanism may follow and the rest of the hole's rotational energy, if any left, would be further released. 
Hongsu Kim, Hyun Kyu Lee, Chul H. Lee