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+//example 8
+//calculating change in enthalpy
+clear
+clc
+h1=273.2 //specific heat enthalpy for oxygen at 300 K
+h2=1540.2 //specific heat enthalpy for oxygen at 1500 K
+T1=300 //initial temperature in K
+T2=1500 //final temparature in K
+x=poly([0],'x');
+Cp=0.88-0.00001*x+0.54*x^2-0.33*x^3 //expression for constant pressure specific heat enthalpy for oxygen
+dh1=h2-h1 //this change in specific heat enthalpy is calculated using ideal gas tables
+dh2=1000*integrate('0.88-0.00001*x+0.54*x^2-0.33*x^3','x',T1/1000,T2/1000) //using empirical equation
+dh3=0.922*(T2-T1) //it is claculated if we assume specific heat enthalpy to be constant and uses its value at 300K
+dh4=1.0767*(T2-T1) //it is claculated if we assume specific heat enthalpy to be constant and uses its value at 900K i.e mean of initial and final temperature
+printf("\n Hence,change in specific heat enthalpy if ideal gas tables are used is dh1=%.1f kJ/kg. \n", dh1)
+printf("\n if empirical equations are used, dh2=%.1f kJ/kg. \n", dh2)
+printf("\n if specific heat is assumed to be constant and using its value at T1, dh3=%.1f kJ/kg. \n", dh3)
+printf("\n if specific heat is assumed to be constant at its value at (T1+T2)/2, dh4=%.1f kJ/kg. \n", dh4) \ No newline at end of file