Some are also suggesting that airport security has become an issue of national security and should be made a function of the federal government.
Instead of a constant non-coaxial plastic modulus in the original yield vertex non-coaxial model, the non-coaxial modulus is made a function of cumulative deviatoric plastic strain.
The value of thermal diffusivity is commonly in the order of ~10−6 m2 s−1; however, it can be made a function of thermal conductivity ((lambda), W m−1 K−1), i.e., (kappa sim lambda /(2.3 times 10^{6} )) (Beck 1988).
Similarly to the Shell model, the ITD is all about dividing up canopy space and so, in common with it, it naturally captures competition between large trees: growth can simply be a made a function of exposed crown area, ECA ([49]).
The RH of the outside atmosphere is an adjustable parameter in the model; it can be set to a constant value or made a function of time.
To reduce errors, parameters in eq. 9 could be made a function of wind angle, but this complexity did not seem warranted, especially since the largest errors (8 - 12%) occurred at low traffic volumes (< 2,000 vehicles hr-1), which would normally yield small concentrations.
