#NEWLINE# def relaxation_frequency_nitrogen( pressure , temperature , h , reference_pressure = REFERENCE_PRESSURE , reference_temperature = REFERENCE_TEMPERATURE ) : #NEWLINE# #INDENT# '\n    Relaxation frequency of nitrogen :math:`f_{r,N}`.\n    \n    :param pressure: Ambient pressure :math:`p_a`\n    :param temperature: Ambient temperature :math:`T`\n    :param h: Molar concentration of water vapour :math:`h`\n    :param reference_pressure: Reference pressure :math:`p_{ref}`\n    :param reference_temperature: Reference temperature :math:`T_{ref}`\n    \n    The relaxation frequency of nitrogen is calculated using\n    \n    .. math:: f_{r,N} = \\frac{p_a}{p_r} \\left( \\frac{T}{T_0} \\right)^{-1/2} \\cdot \\left( 9 + 280 h \\exp{\\left\\{ -4.170 \\left[ \\left(\\frac{T}{T_0} \\right)^{-1/3} -1 \\right] \\right\\} } \\right)\n    \n    ' #NEWLINE# return ( ( ( pressure / reference_pressure ) * ( ( temperature / reference_temperature ) ** ( - 0.5 ) ) ) * ( 9.0 + ( ( 280.0 * h ) * np . exp ( ( ( - 4.17 ) * ( ( ( temperature / reference_temperature ) ** ( ( - 1.0 ) / 3.0 ) ) - 1.0 ) ) ) ) ) )