h_vap: heat of vaporization (J / mol)

.get_hvap(T_leaf, unitless)

Arguments

T_leaf: Leaf temperature in Kelvin
unitless: Logical. Should function use parameters with units? The function is faster when FALSE, but input must be in correct units or else results will be incorrect without any warning.

Value

Value in J/mol of class units

Details

Heat of vaporization: The heat of vaporization (\(h_\mathrm{vap}\)) is a function of temperature. I used data from on temperature and \(h_\mathrm{vap}\) from Nobel (2009, Appendix 1) to estimate a linear regression. See Examples.

References

Nobel PS. 2009. Physicochemical and Environmental Plant Physiology. 4th Edition. Academic Press.

Examples


# Heat of vaporization and temperature
## data from Nobel (2009)

T_K <- 273.15 + c(0, 10, 20, 25, 30, 40, 50, 60)
h_vap <- 1e3 * c(45.06, 44.63, 44.21, 44.00, 
                 43.78, 43.35, 42.91, 42.47) # (in J / mol)
                 
fit <- lm(h_vap ~ T_K)

## coefficients are 56847.68250 J / mol and 43.12514 J / (mol K)

coef(fit) 
#> (Intercept)         T_K 
#> 56847.68250   -43.12514 

T_leaf <- 298.15
h_vap <- set_units(56847.68250, J / mol) - 
           set_units(43.12514, J / mol / K) * set_units(T_leaf, K)

## h_vap at 298.15 K is 43989.92 [J/mol]

set_units(h_vap, J / mol)
#> 43989.92 [J/mol]

tealeaves:::.get_hvap(set_units(298.15, K), FALSE)
#> 43989.92 [J/mol]