function [sf]=sf(T) 
  %fluid specific entropy [kJ/kg*K] at T [celsius] 
 
 Tsat=[0:10:300,320,340,360,374.15];
  %saturation temperature in celsius

 sliq=[0,0.151,0.2966,0.4369,0.5725,0.7038,0.8312,0.9549,1.0753,1.1925,1.3069,1.4185,1.5276,1.6344,1.7391,1.8418,1.9427,2.0419,2.1396,2.2359,2.3309,2.4248,2.5178,2.6099,2.7015,2.7927,2.8838,2.9751,3.0668,3.1594,3.2534,3.448,3.6594,3.9147,4.4298];
  %saturated liquid specific entropy in kJ/kg*K

sf=interp1(Tsat,sliq,T);