def Suzuki_UFL(Hc=None):
Hc = Hc/<NUM_LIT><EOL>UFL = <NUM_LIT>*Hc + <NUM_LIT>*Hc*Hc + <NUM_LIT><EOL>return UFL/<NUM_LIT><EOL>
r'''Calculates upper flammability limit, using the Suzuki [1]_ correlation.
    Uses heat of combustion only.

    The upper flammability limit of a gas is air is:

    .. math::
        \text{UFL} = 6.3\Delta H_c^\circ + 0.567\Delta H_c^{\circ 2} + 23.5

    Parameters
    ----------
    Hc : float
        Heat of combustion of gas [J/mol]

    Returns
    -------
    UFL : float
        Upper flammability limit, mole fraction

    Notes
    -----
    UFL in percent volume in air according to original equation.
    Hc is at standard conditions in the equation, in units of MJ/mol.
    AAPD = 1.2% for 95 compounds used in fit.
    Somewhat better results than the High and Danner method.
    4.9% < UFL < 23.0%
    -890.3 kJ/mol < dHc < -6380 kJ/mol
    r^2 = 0.989
    Sample calculations provided for all chemicals, both this method and
    High and Danner. Examples are from the article.

    Predicts a UFL of 1 at 7320190 J and a UFL of 0 at -5554160 J.

    Examples
    --------
    Pentane, literature 7.8% UFL

    >>> Suzuki_UFL(-3536600)
    0.0831119493052

    References
    ----------
    .. [1] Suzuki, Takahiro, and Kozo Koide. "Short Communication: Correlation
       between Upper Flammability Limits and Thermochemical Properties of
       Organic Compounds." Fire and Materials 18, no. 6 (November 1, 1994):
       393-97. doi:10.1002/fam.810180608.