AQSys: Merchuk's nonlinear Equation

In LLSR: Data Analysis of Liquid-Liquid Systems using R

Description

.

Perform a nonlinear regression fit using any of the several mathematical descriptors implemented in order to calculate the equation's parameters.

Usage

AQSys(dataSET, ...)

## Default S3 method:
AQSys(dataSET, modelName = "merchuk", Order = "xy", ...)

Arguments

dataSET	- Binodal Experimental data that will be used in the nonlinear fit
...	Additional optional arguments. None are used at present.
modelName	- Character String specifying the nonlinear empirical equation to fit data. The default method uses Merchuk's equation. Other mathematical descriptors can be listed using AQSysList().
Order	Defines how the data is organized in the Worksheet. Use "xy" whether the first column corresponds to the lower phase fraction and "yx" whether the opposite.

Details

The function returns functions parameters after fitting experimental data to the equations listed in AQSysList().

Value

A list containing three data.frame variables with all data parsed from the worksheet and parameters calculated through the available mathematical descriptions.

References

MURUGESAN, T.; PERUMALSAMY, M. Liquid-Liquid Equilibria of Poly(ethylene glycol) 2000 + Sodium Citrate + Water at (25, 30, 35, 40, and 45) C. Journal of Chemical & Engineering Data, v. 50, n. 4, p. 1392-1395, 2005/07/01 2005. ISSN 0021-9568. (doi: 10.1021/je050081k)

MERCHUK, J. C.; ANDREWS, B. A.; ASENJO, J. A. Aqueous two-phase systems for protein separation: Studies on phase inversion. Journal of Chromatography B: Biomedical Sciences and Applications, v. 711, n. 1-2, p. 285-293, 1998. ISSN 0378-4347. (doi: 10.1016/s0378-4347(97)00594-x)

TANG, X. et al. The study of phase behavior of aqueous two-phase system containing [Cnmim] BF 4 (n=2, 3, 4)+(NH4)2SO4 + H2O at different temperatures. Fluid Phase Equilibria, v. 383, p. 100-107, 2014. ISSN 0378-3812. (doi: 10.1016/j.fluid.2014.09.029)

GONZALEZ-TELLO, P. et al. Liquid-Liquid Equilibrium in the System Poly(ethylene glycol) + MgSO4 + H2O at 298 K. Journal of Chemical & Engineering Data, v. 41, n. 6, p. 1333-1336, 1996/01/01 1996. ISSN 0021-9568. (doi: 10.1021/je960075b)

CHEN, Y. et al. Liquid-liquid equilibria of aqueous biphasic systems composed of 1-butyl-3-methyl imidazolium tetrafluoroborate+ sucrose/maltose+ water. Journal of Chemical & Engineering Data, v. 55, n. 9, p. 3612-3616, 2010. ISSN 0021-9568. (doi: 10.1021/je100212p)

See Also

• AQSys.default

• AQSys.plot

• AQSys.LevArmRule

• AQSysOthmer

• AQSysBancroft

Examples

# Populating variable dataSET with binodal data
dataSET <- peg4kslt[ , 1:2]
# Fitting dataSET using Merchuk's function
AQSys(dataSET)

Example output

    Be aware that LLSR is a collaborative package that still in
    development and your help is essential.

    If you found any bugs or have a suggestion, do not hesitate and
    contact us on https://github.com/diegofcoelho/LLSR/issues.

    You also can fork this project directly from github and commit
    improvements to us (http://diegofcoelho.github.io/LLSR/).

    The information used in the database was obtained free of charge
    but it might be copyrighted by third parties and references must
    be included appropriately.

Nonlinear regression model
  model: YC ~ P1 * exp(P2 * (XC^(0.5)) - P3 * (XC^3))
   data: XYdt
        P1         P2         P3 
94.9268443 -0.5082750  0.0007876 
 residual sum-of-squares: 176.8

Number of iterations to convergence: 8 
Achieved convergence tolerance: 1.49e-08

LLSR documentation built on Feb. 18, 2021, 1:09 a.m.