Function describing exponential decline from a defined starting value, with a decreasing rate constant.

The form given here differs slightly from the original reference by Gustafson and Holden (1990). The parameter beta corresponds to 1/beta in the original equation.

FOMC.solution(t, parent.0, alpha, beta)

Arguments

t
Time.
parent.0
Starting value for the response variable at time zero.
alpha
Shape parameter determined by coefficient of variation of rate constant values.
beta
Location parameter.

Note

The solution of the FOMC kinetic model reduces to the SFO.solution for large values of alpha and beta with \(k = \frac{\beta}{\alpha}\).

Value

The value of the response variable at time t.

References

FOCUS (2006) “Guidance Document on Estimating Persistence and Degradation Kinetics from Environmental Fate Studies on Pesticides in EU Registration” Report of the FOCUS Work Group on Degradation Kinetics, EC Document Reference Sanco/10058/2005 version 2.0, 434 pp, http://focus.jrc.ec.europa.eu/dk

Gustafson DI and Holden LR (1990) Nonlinear pesticide dissipation in soil: A new model based on spatial variability. Environmental Science and Technology 24, 1032-1038

Examples

plot(function(x) FOMC.solution(x, 100, 10, 2), 0, 2, ylim = c(0, 100))