type ConcentrationQuantities = enumeration(c_molpm3 "Concentration (mmol/L)", X_kgpkg "Mass fraction (kg/kg)", b_molpkg "Molality (mol/kg)", x_molpmol "Mole fraction (mol/mol)", p_Pa "Partial pressure (Pa)", p_kPa "Partial pressure (kPa)", p_mmHg "Partial pressure (mmHg)", p_bar "Partial pressure (bar)");