TYPE: bug fix

KEYWORDS: chemical reaction rate constant

SOURCE: internal

DESCRIPTION OF CHANGES:

Correct the reaction rate constant for reaction tag usr23.

The prior code had the expression:

    fc    = 3.e-11_dp * (300._dp/temp) ** 3.3_dp

which has been corrected to:
    fc    = 3.e-31_dp * (300._dp/temp) ** 3.3_dp

This change applies only to the following chem_opt options:

MOZART_KPP,MOZCART_KPP,T1_MOZCART_KPP,MOZART_MOSAIC_4BIN_KPP,MOZART_MOSAIC_4BIN_AQ_KPP

LIST OF MODIFIED FILES:

M       chem/KPP/mechanisms/mozart/mozart.def
M       chem/KPP/mechanisms/mozart_mosaic_4bin/mozart_mosaic_4bin.def
M       chem/KPP/mechanisms/mozart_mosaic_4bin_aq/mozart_mosaic_4bin_aq.def
M       chem/KPP/mechanisms/mozcart/mozcart.def
M       chem/KPP/mechanisms/t1_mozcart/t1_mozcart.def

TESTS CONDUCTED:

Gabi Pfister has compared simulations with the old and new rate constant.
Differences are consistent with the modification and are within an expected
range.