Figure 4: Vertical cross section, on x-z plane, of calculated NOx at y=12 m (see Figure 2) in double-fence cases with ( R ¯ C = γρR_c) and as parameters: (a, b) for no removal activity of ACF fences. (b, d) for removal activity with k_c= 1 s^-1, and (e, f) for removal activity with R_c= 3 s^-1. Contour interval is 10 ppb.