Calculates the first derivative of Metselaar model at a given time for the model parameters provided and the environmental conditions given.
dMetselaar_model(t, x, parms, temp_profile)
The value of the first derivative of N at time t
as a list.
numeric vector indicating the time of the experiment.
list with the value of N at t.
parameters for the secondary model. No explicit check of their validity is performed (see section Model Parameters).
a function that provides the temperature at a given time.
\deqn{\frac{dN}{dt} = -N \cdot p \cdot (1/D)^p \cdot (t/Delta)^{p-1} }{
dN/dt = -N * p * (1/D)^p * (t/Delta)^(p-1)} \deqn{D(T) = D_{ref} \cdot 10^{- (T-T_ref)/z} }{
D(T) = D_R * 10^(- (T-T_ref)/z )}
temp_ref: Reference temperature for the calculation.
D_R: D-value at the reference temperature.
z: z-value.
p: shape factor of the Weibull distribution.
Delta: Scaling parameter
The model is developed from the isothermal Metselaar model without taking into account in the derivation the time dependence of \(\delta_T\) for non-isothermal temperature profiles.
This function is compatible with the function
predict_inactivation
.
predict_inactivation