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This section lists past changes related to AIOMFAC-web in reverse chronological order.

• Back to recent announcements.

• June 19, 2023: AIOMFAC-web model update to v3.05. This minor version update fixes a bug introduced with v3.04, which slightly affected activity coefficient calculations of mixtures containing organics with secondary hydroxyl functional groups. We thank Darren Rowland for noticing this and for informing us.

• March 18, 2023: AIOMFAC-web model update to v3.04. This minor version update fixes a bug introduced with v3.03, which affected only the output of molalities reported for water and organic species as well as the individual mole fractions of ions (other outputs, such as activity coefficients and activities, were not affected). We thank Thomas Preston for notifying us about this issue.

• February 11, 2022: AIOMFAC-web model update to v3.03. This minor version update adds support of AIOMFAC-VISC viscosity calculations for systems involving carbonate, bicarbonate and IO₃^-.

• December 9, 2021: AIOMFAC-web model update to version 3.01. This major version update provides a number of new features.
  (1) Based on the work by Hang Yin et al.: additions of new inorganic species (ions I^-, IO₃^-, HCO₃^-, CO₃^2-, OH^- and aqueous CO₂) supporting calculations involving iodine species and the CO₂(aq)–bicarbonate–carbonate system, including solving the dissociation equilibria (and associated effects on pH). Other ion–organic interaction parameters were also updated; for details see the article by Yin et al. (2022).
  (2) Based on the work by Lilek and Zuend: viscosity calculations of aqueous electrolyte mixtures as well as mixed organic–inorganic phases have been introduced; for details see the article by Lilek and Zuend (2022). This addition is a major update of the AIOMFAC-VISC model within AIOMFAC-web, substantially enhancing the range of applicability. See the Hints & Examples page for more information.
  Additional notes on underlying source code updates are provided at https://github.com/andizuend/AIOMFAC.

• July 18, 2020: AIOMFAC-web model update to version 2.32. This version provides added selection choices for UNIFAC's primary and secondary amine groups, as well as nitro groups. However, these functional groups are currently only supported for electrolyte-free systems.

• September 26, 2019: AIOMFAC-web model update to version 2.31. The underlying model code has been updated to resolve an issue with systems of a large number of components, introduced with the previous version, resulting in faster model execution speed. Also, an issue on the McGill server when running the model via the upload of an input file has been fixed.

• August 23, 2019: A new feature, the prediction of the dynamic viscosity of an aqueous organic mixture (phase) has been introduced with this update. The viscosity prediction uses the recently developed AIOMFAC-VISC model by Gervasi et al. (2019). See the Hints & Examples page for more information. The model was updated to version 2.30. This version update further includes new or updated AIOMFAC interaction parameters for the following cation–anion combinations: K⁺ ↔ SO₄^2-, K⁺ ↔ HSO₄^-, Ca²⁺ ↔ HSO₄^-, Mg²⁺ ↔ HSO₄^-, and Li⁺ ↔ HSO₄^-.

• January 23, 2019: A minor model update to version 2.21. A bug concerning input composition verification and a related error check have been fixed (no changes to actual AIOMFAC calculations).

• August 13, 2018: Several changes were made to hardware, software and content of the AIOMFAC website.  (1) The website is now hosted permanently on a new server at McGill University, accessible via the following URL: https://aiomfac.lab.mcgill.ca. The previous, temporary server at McGill will redirect to this address. The Caltech-hosted website remains available.  (2) The contents of this page as well as the Hints & Examples page, previously listed as "Help" page, were updated.  (3) A new option on the "Run model" input form makes it possible to display the model results page in a new browser tab. This allows keeping the input form open for easier adjustments.  (4) AIOMFAC-web has been updated to version 2.20, which includes minor revisions and optimization of the code.  (5) For the adventurous: the Fortran source code of the AIOMFAC-web version 2.20 (and future updates) and supporting information is made availabe publicly via https://github.com/andizuend/AIOMFAC.

• November 22, 2017: Recent hardware issues and related repairs of the server at Caltech have caused temporary unavailability of this website. To avoid longer unavailabilities in future, the AIOMFAC model website is now also hosted on a server at McGill University, currently accessible via the following URL: http://web.meteo.mcgill.ca/aiomfac/. The Caltech-hosted website (http://www.aiomfac.caltech.edu) remains available.

• May 15, 2015: A search tool has been added to the navigation menu to aid you in finding relevant information on this website.

• April 24, 2014: Initial input data validation, error, and warning checks have been further improved (including the blocking of automated spam upload). The model version was changed to 2.18. However, these changes do not affect the actual AIOMFAC code nor model output.

• June 19, 2013: The AIOMFAC model has been corrected for a typo in the supplementary tables of Hansen et al. (1991) for the relative surface area parameter of the ketone subgroup CH₃CO. The previously used value (1.448 instead of 1.488) led to slight deviations of activity coefficients in affected systems, e.g., noticeable at conditions of very high dilution in the system of water + acetone. We thank Steven Compernolle for the hint. The AIOMFAC-web version has been changed to 2.16.

• December 10, 2012: Additional error and warning checks have been implemented in the AIOMFAC-web model to prevent certain types of incorrect input data. The model version was changed to 2.15.

• October 16, 2012: The webpages have been updated to be compliant with HTML5 syntax and features. The AIOMFAC-web model has been updated to version 2.14 (including output of results in HTML5 syntax and internal performance upgrades).

• August 17, 2012: The model input page has been updated to fix compatibility issues with older web browsers (and their interpretation of JavaScript code).

• June 06, 2012: AIOMFAC-web version bug-fix update to 2.11. A bug in the model code slightly affecting activity coefficients in mixtures containing organic compounds and non-1:1-electrolytes has been corrected. Thanks to Steven Compernolle for pointing out this error.

• May 11, 2012: AIOMFAC-web version update to 2.10. New functional groups are made available in AIOMFAC-web: hydroperoxide, peroxyacid, peroxide, peroxyacyl nitrate (PAN), and organonitrate. The new functional groups and the parameterization of their interactions with other functional groups and inorganic ions are described in Zuend and Seinfeld (2012). The list of available functional groups and the interaction matrix shown on the page About AIOMFAC have been updated accordingly.

• April 01, 2012: AIOMFAC-web version update to 2.02. The version update includes a minor correction in TeX format of model output in text files, allows now 101 data points per model run, and addresses numerical issues at extremely high electrolyte concentrations.

• February 17, 2012: Additional examples of AIOMFAC-web calculations have been added to the Hints & Examples page. It is demonstrated how the water content and mixture composition at a given RH can be computed and how the solubility and deliquescence RH of a component in a multicomponent solution can be determined with AIOMFAC.

• January 10, 2012: The AIOMFAC website has been launched with AIOMFAC-web version 2.0 available for online calculations.

  AIOMFAC-web 2.0 covers water, inorganic ions and the following organic functional groups: hydroxyl, carboxyl, ketone, aldehyde, ether, ester, alkenyl, aromatic hydrocarbon, aromatic carbon-alcohol, and different alkyl groups. The inorganic ions available are: H⁺, Li⁺, Na⁺, K⁺, NH₄⁺, Mg²⁺, Ca²⁺, Cl^-, Br^-, NO₃^-, HSO₄^-, and SO₄^2- (see further here).