Compute derivative of specific entropy, low T region
function s0_Tlow_der extends Modelica.Icons.Function; input IdealGases.Common.DataRecord data "Ideal gas data"; input SI.Temperature T "Temperature"; input Real T_der(unit = "K/s") "Temperature derivative"; output Real s_der(unit = "J/(kg.K.s)") "Derivative of specific entropy at temperature T"; end s0_Tlow_der;