The GEMSFITS test suite is a set of examples for different parameter optimization problems. The
projects can be used as tutorials for learning GEMSFITS and as a source for different types of optimization
setups. It is recommended to copy-paste different sections from fitting Tasks found in the
Tests projects into the users own optimization project and do the necessary modifications.
The tests are included into GEMSFITS installer (see "/Tests/"); they will be automatically copied in the user tests directory upon the first installation; upon the upgrade, the folder will be overwritten.
Each project is opened in GEMSFITS by Open Project ... and clicking on the *.pro file found in the folder named after the test.
Each test project comes with pre-formated experimental data found in the /dbimport/ folder, the exported GEMS3K chemical system files, and the GEM-Selektor project both found inside the /GEMS/ folder for each test example.
It is recommended that the user uses the pre-formated experimental data files distributed with the text projects as templates and doing necessary changes for loading their own experimental data into the fitting project.
|Test fitting project
|Aqueous-Al||Fitting multiple aqueous species independent (type F) and reaction constrained (type R).
For one of the reactions (AlOH+2) the logK values are calculated using a logK function of water density (logK_dRHOw function
and coefficients described in LogKFun) and literature parameters, and for a second one (NaAl(OH)4@) it uses the logK values
from the input system file calculated in the initial step.
The test also uses the nested functionality to fix the calculated pH at each optimization step to the measured one by titrating NaOH and HCl.
|| Fitting Calcite-Strontianite
solid solution interaction parameters against excess Gibbs energy data, without using full
equilibrium calculations (UseEqC set to -1 - no equilibrium, instead of 1 with equilibrium)
Fitting G0 of end members and non ideal interaction parameters for a CSH
solid-solution against measured Ca(aq), Si(aq), Ca/Si in solid, and mean silicate chain length
Fitting G0 of sorption sites against Rd (partition coefficient) measured values form
experiments, with and without the presence of air.
Fitting Pitzer interaction parameters as a function of T and P against synthetic
experimental data from Archer et al. (1992). Using 120% +- bounds from initial
values for the parameters (PBPerc set to 120). !!convergence problems, needs to be checked / updated.
A. Test example for fitting Ti in quartz regular solid solution model parameters against experimental data of Thomas et al., (2010) and Wark and Watson (2006). TiQ_normal.pro
B. Using the fitted parameters from TiQ_normal for doing inverse modeling calculations determining the T & P of formation of quartz crystals based on their Ti content. TiQ_inverse.pro
Results are found in Inv. Mod. Results tab of the Results window.
(always under construction)