\begin{table}%t5
\caption {\label{tab_effects}Ratios of the predicted to apparent emissivities, using
the same processing as for the data with different models. }
%\centerline
 {\begin{tabular}{   c  c   c   c   c   c   c   c   c   c  }
\hline
\hline
 $\rm \lambda$ ($\rm \mic$) & \multicolumn{3}{c }{Grain size distribution}& \multicolumn{3}{c }{ISRF strength mixture} &  \multicolumn{3}{c }{Grain composition}  \\
 & $X\rm _{ISRF}=0.05$ & $X\rm _{ISRF}= 0.5$& $X\rm _{\rm ISRF}=4$& 
 $\rm \alpha=2.5$ &$\rm \alpha= 2$& $\rm \alpha= 1.25$& $T\rm _2=10$~K & 
 $T\rm _2= 15$~K & $T\rm _2=22$ K \\
\hline
 100 & 1.13 & 0.89 & 0.93 & 1.20 & 1.46 & 3.06 & 1.06 & 1.29 & 1.16 \\
 140  & 1.13 & 0.96 & 0.98 & 1.23 & 1.45 & 2.66 & 1.12 & 1.27 & 1.14 \\
 240  & 1.11 & 1.00 & 1.02 & 1.17 & 1.29 & 1.84 & 1.03 & 1.19 & 1.13 \\
 550  & 1.07 & 1.03 & 1.03 & 1.09 & 1.12 & 1.27 & 0.96 & 1.05 & 1.04 \\
 850  & 1.04 & 1.02 & 1.02 & 1.05 & 1.07 & 1.14 & 1.07 & 1.10 & 1.08 \\
 1400  & 1.00 & 0.99 & 0.99 & 1.01 & 1.01 & 1.05 & 1.00 & 1.04 & 1.05 \\
 2100  & 0.99 & 0.99 & 0.99 & 0.99 & 1.00 & 1.01 & 0.98 & 1.01 & 1.03 \\
\hline
\end{tabular}}
\smallskip
Columns~2--4: using the \citet{Desert90} model at various ISRF strength ($X_{\rm ISRF}$). Columns~5--7:
assuming a mixture of the radiation field intensity on each LOS, using
the model by \citet{Dale01} for various values of
the mixing parameter~$\rm \alpha$. Columns~8--10: using the two component model of
\citet{Finkbeiner99} for different temperatures of the warm component
($T\rm _2$).
\end{table}