dryingmodels: Modeling Seed Drying Kinetics

In seedwater: Models for Drying and Soaking Kinetics of Seeds

Description

An interactive function to fit nonlinear models for seed drying kinetics.

Usage

dryingmodels(moisture, time)

Arguments

moisture	a numeric vector containing values of seed water content of weight of seed sample. See Details.
time	a numeric vector containing values of drying time.

Details

dryingmodels is set to fit curves of moisture ratio (MR) rather than moisture. It is automatically calculated through the equation:

MR = \frac{\code{moisture} - Mf}{Mi - Mf}

where Mi and Mf are the initial and final values of seed moisture.

These are the currently available models:

(Page) MR = exp(-K * x^n)

(Henderson and Pabis) MR = A * exp(-K * x)

(Henderson and Pabis modified) MR = A * exp(-K * x) + b * exp(-K0 * x) + exp(-K1 * x)

(Midilli) MR = A * exp(-K * x^n) + b*x

(Diffusion approximation) MR = A * exp(-K * x) + (1 - A) * exp(-K * b * x)

(Two terms exponential 1) MR = A * exp(-K0 * x) + b * exp(-K1 * x)

(Two terms exponential 2) MR = A * exp(-K * x) + (1 - A) * exp(-K * A * x)

(Logarithmic) MR = A * exp(-K * x) + b

(Thompson) MR = exp(-A - sqrt(A^2 + 4 * b * x))/(2 * b)

(Newton) MR = exp(-K * x)

(Verma) MR = A * exp(-K * x) + (1 - A) * exp(-K1 * x)

(Wang and Sing) MR = 1 + A * x + b * x^2

where x represents time and A, K, n, b, K0 and K1 are the model parameters.

Value

An object of class nls containing the parameter estimates.

Side Effects

An interactive graphic is displayed for selecting the model and the initial values for the parameters.

Author(s)

Anderson Rodrigo da Silva <[e-mail]>

See Also

nls, soakingmodels

Examples

data(waterloss)
if (interactive()) {
   res <- with(waterloss, dryingmodels(moisture = WaterContent, time = Time))
   summary(res)
}

# End (not run)

seedwater documentation built on Jan. 13, 2021, 6:42 p.m.