Values of σ_e at 1200GHz (250μm), T and L versus the average velocity of each Hi component. These dust parameters were estimated from the SED fit over the range 353 to 3000GHz to a modified black body with β = 1.8. Black and blue symbols are for LVC and IVC, respectively. The different symbols in blue represent IVCs associated with specific complexes: IV Arch (dot), IV/LLIV Arch (triangle), Complex K (square) and PP Arch (star). In each panel the dotted line represent the value for the diffuse ISM obtained with the high-latitude FIRAS spectrum (see Fig. 17). Error bars are given for each data point, some being smaller than the symbol size.