2003 to 2008
25 July 2008
BUGFIX RELEASE of GEMS-PSI version 2.2.4 rc7 is now available for download for Win32 XP/Vista; Linux 32/64 rpm, and Intel Mac OS X 10.5 platforms. In this version of GEM-Selektor, a mismatch in representation of output activities and activity coefficients has been fixed. This mismatch is potentially important for calculation of equilibria involving concentrated aqueous solutions. A test project (suggested by B.Lothenbach) is provided here; using this project with this and any older version of GEM-Selektor for comparisons, you will be able to see the magnitude of bias corrected by the present bugfix. In old projects where the ionic strength is less than 0.5 m, the bias is usually small and hardly visible on the Process or GtDemo plots. The detailed description of the mismatch and how it has been corrected is provided in the (updated) file Activity-Coeffs.pdf.
19 May 2008
BUGFIX RELEASE of GEMS-PSI version 2.2.3 rc6 is now available for download for Win32 XP; Linux 32/64 rpm, and Intel Mac OS X 10.5 platforms. In this version of GEM-Selektor, a few small annoying bugs were fixed, and some documentation extensions made (in particular, for using Pronsprep algorithms in ReacDC module). More example Process scripts (written by Th.Wagner) for sequential reactors mode were added as well.
This version of GEMS-PSI, for the first time, is provided as a .deb package for the Kubuntu 8 "Hardy Heron" 32-bit linux with KDE-3. We hope that this development will further expand the GEM-Selektor user community to Southern Hemisphere.
31 March 2008
INTERIM RELEASE of GEMS-PSI version 2.2.3 rc5 is now available for download for Win32 XP; Linux 32/64 rpm, as well as for Intel Mac OS X 10.4 and 10.5 platforms. In this version of GEM-Selektor, the "Smart Initial Approximation" (SIA) mode has been further improved and tested. There were also numerous changes in the GEMIPM2 kernel code aimed at better reproducibility of results in automatic initial aproximation. Three methods of temperature/pressure extrapolation for aqueous complexes and non-polar dissolved species were built-in (contributed by Dr. Th. Wagner, ETHZ), documentation pending.
13 February 2008
INTERIM RELEASE of GEMS-PSI version 2.2.2 rc4 is now available for download for Win32; Linux 32/64 rpm platforms; installers for Apple G4/G5 and Apple Intel PCs are coming soon. This is the first released version of GEM-Selektor where a "Smart Initial Approximation" (SIA) mode can be used e.g. in Process Simulators. Depending on the system size, this accelerates calculations 5 times and more compared with version 2.2.1, or 10 to 60 times compared with versions 2.2.0 rc0 or earlier. The optional SIA mode needs an interim period of extensive testing.
07 January 2008
MAINTENANCE RELEASE of GEMS-PSI version 2.2.1 rc3 is now available for download for Win32; Linux 32/64 rpm platforms, as well as (after 2 years break) for Apple G4/G5 PCs. We also provide for the first time the installation bundle for Apple Intel PCs (for now, Mac OS X 10.4 only). The variant for Mac OS X 10.5 may be expected in the near future.
07 November 2007
NEW RELEASE! GEMS-PSI version 2.2.0 rc2 code is now available on our new web page (https://gems.web.psi.ch) for download for Win32 and Linux rpm platforms. This version uses the performance-optimized GEM IPM-2 numerical engine which runs 2 to 30 times faster than that in previous versions. It also incorporates important bugfixes, some of which result in improved quality and precision of calculated phase assemblage and speciation. We highly recommend upgrading to the latest GEMS version!
03 August 2007
COMING SOON! New release of GEM-Selektor code - version 2.2.0 release candidate - will be available for download for Win32 and Linux rpm platforms. This version uses the performance-optimized GEM IPM-2 numerical engine which runs 2 to 30 times faster than that in previous versions. From version 2.2.1 on, the GEM solver will also be available as a standalone batch program GEMIPM2K which can be coupled with an existing or a new fluid-mass-transport, reaction path, or sensitivity analysis code, including those running on high-performance computers and clusters. A major extension in version 2.2.0 is related to built-in implementations of models of non-ideal mixing in multi-component solid, liquid solutions and fluids (see List of Changes). Numerous bugfixes (see List of Corrections) result in unmatched stablilty of the program and in a better convergence than it was possible before.
31 August 2006
New release of GEM-Selektor code - version 2.1.2 (release candidate 3) - is now available for download (for Win32 and Linux 32/64 platforms). This version contains an upgraded GEM IPM-2 numerical engine that uses the JAMA C++ TNT numerical algebra package; due to this, GEMS runs faster and stabler as previously, and converges better. For bugfixes, see List of Corrections; for extensions, see List of Changes. The online Screenshot tutorial has been revised and extended with sections on surface complexation modeling, including setup of MUSIC-type GEM SCMs.
31 October 2005
COMING SOON! After 13 months of development, a major new release of GEM-Selektor code - version 2.1.0 (release candidate 0) - will be available for download within next days. This version contains many bugfixes (several important ones, see List of Corrections) and extensions (see List of Changes) including new CD-MUSIC implementation of surface complexation models with more precise surface activity coefficient terms replacing the older SAT (surface activity terms).
07 September 2004
GEM-Selektor v. 2.0.1-rc7 (release candidate 7) now replaces the release candidate 6.
This bugfix release is available for for Win32, Linux and Mac OS X. It fixes a problem with database file compression function (see List of Corrections for details).
03 August 2004
GEM-Selektor v. 2.0.1-rc6 (release candidate 6) is now available for downloading for Win32, Linux and Mac OS X !
This is the first release available for all three major computing platforms. It contains many improvements in the graphical user's interface (see List of Changes for details).
30 June 2004
GEM-Selektor v. 2.0.0-rc5 (release candidate 5) is now available for downloading! Contains bugfixes of low-to medium importance (see List of Corrections and List of Changes for details).
31 October 2003
GEM-Selektor v. 2.0.0-rc4 (release candidate 4) is now available for downloading! It is the first release that comes as a real installer for Win32 (creates shortcuts, registry entries, etc.) and can be deinstalled in a standard way.
25 September 2003
GEM-Selektor v. 2.0.0-rc3 (release candidate 3) is now available for downloading! See List of Changes for details.
Check the Screenshot online tutorial - now strongly extended to aqueous partitioning equilibria involving solid solutions and surface complexation.
18 August 2003
GEM-Selektor v. 2.0.0-rc2 (release candidate 2) is now available for downloading! See List of Changes for details.
02 April 2003
GEM-Selektor v. 2.0.0-rc1 (release candidate 1) is now available for downloading! See List of Changes for details.
31 March 2003
The "complementary" part of the Default chemical thermodynamic database is now extended with ca. 570 organic aqueous species imported from the Slop98.dat database (http://epsc.wustl.edu/geopig).
14 March 2003
The on-line Screenshot Tutorial is now extended to show how to model irreversible mass transfer using Process Simulators and how to plot various results of such simulations using GtDemo data samplers.
13 March 2003
The GEMS package download page now explains what to do if you experience problems with downloading GEM-Selektor installation files.