PRO Phycon

; This procedure develops a library of physical constants that will be used throughout
; this course.

;Avogadro's Number [mol-1]
DEFSYSV, '!Na',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Na', 6.022D23, 1
ENDIF ELSE PRINT,'System Variable !Na already Exists'

;Gravitational Acceleration [m/s^2]
DEFSYSV, '!Grav',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Grav', 9.807D0, 1
ENDIF ELSE PRINT,'System Variable !Grav already Exists'

;Molecular Wgt of Dry Air [g/mol]
DEFSYSV, '!Md',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Md', 28.966D0, 1
ENDIF ELSE PRINT,'System Variable !Md already Exists'


;Molecular Wgt of Water Vapor [g/mol]
DEFSYSV, '!Mv',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Mv', 18.016D0, 1
ENDIF ELSE PRINT,'System Variable !Mv already Exists'


;Universal Gas Constant [J/mol/K]
DEFSYSV, '!Rstar',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Rstar', 8.3143D0, 1
ENDIF ELSE PRINT,'System Variable !Rstar already Exists'


;Gas Constant for Dry Air [J/kg/K]
DEFSYSV, '!Rd',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Rd', 287.04D0,1
ENDIF ELSE PRINT,'System Variable !Rd already Exists'


;Gas Constant for Water Vapor [J/kg/K]
DEFSYSV, '!Rv',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Rv', 461.5D0, 1
ENDIF ELSE PRINT,'System Variable !Rv already Exists'


;Specific Heat of Dry Air (Constant Pressure) [J/kg/K]
DEFSYSV, '!Cpd',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Cpd', 1005.D0, 1
ENDIF ELSE PRINT,'System Variable !Cpd already Exists'


;Specific Heat of Dry Air (Constant Volume) [J/kg/K]
DEFSYSV, '!Cvd',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Cvd', 718.D0, 1
ENDIF ELSE PRINT,'System Variable !Cvd already Exists'

;Specific Heat of Water Vapor (Constant Pressure) [J/kg/K]
DEFSYSV, '!Cpv',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Cpv', 1850.D0, 1
ENDIF ELSE PRINT,'System Variable !Cpv already Exists'

;Specific Heat of Water Vapor (Constant Volume) [J/kg/K]
DEFSYSV, '!Cvv',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Cvv', 1390.D0, 1
ENDIF ELSE PRINT,'System Variable !Cvv already Exists'

;Specific Heat of Water (@ 0 degrees C) [J/kg/K]
DEFSYSV, '!Cw',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Cw', 4218.D0, 1
ENDIF ELSE PRINT,'System Variable !Cw already Exists'

;Absolute Temperature of 0 degrees C  [K]
DEFSYSV, '!Tzero',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Tzero', 273.15D0, 1
ENDIF ELSE PRINT,'System Variable !Tzero already Exists'

;Latent Heat Vaporization at 0 degrees C
DEFSYSV, '!LV0',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!Lv0', 2.500D6, 1
ENDIF ELSE PRINT,'System Variable !Lv0 already Exists'

;Saturation Vapor Pressure at 0 degrees C [Pa]
DEFSYSV, '!es0',EXISTS=alive
IF (ALIVE NE 1) THEN BEGIN 
  DEFSYSV, '!es0', 611.21D0, 1
ENDIF ELSE PRINT,'System Variable !es0 already Exists'



END