equation icon  9[c2 - 1 + (2 + w + c2)r/c] [4 r ] Stot = -----------------s---3----3--------s-------------------- ---E-D - (1 + w)U . (291) [3(1 + w)(1 + r/c) + 4rE /r][3w + 3(1 + 2w)r/2c + rE/r] 3 r