Tom Meuzelaar

Hi: It sounds like you are using a foreign language operating system- is that correct? Regards, Tom Meuzelaar RockWare, Inc.

Hello: The reason that you get different plots for the extended LLNL databases at temperatures slightly above and below 25C is that the species FeCl2+ and Fe(OH)3 only have equilibrium constant data given at 25C- thus, they are ignored in the diagrams with slightly higher or lower temperature. If you want to extend the temperature range for these two species, turn on the extrapolate option via the Plot - Diagram menu. Hope that helps, Tom Meuzelaar RockWare, Inc.

Thanks to Craig Cooper, Idaho National Laboratory, for providing a few pointers on how Mac users can get their hardware locks working correctly in Windows Parallels. Craig writes: The basic problem is to force the computer to register the dongle under the Windows Parallels OS rather than the Mac OS One way to do this is to plug the dongle into the port while the windows OS is booting. This tends to force the windows OS to recognize the dongle during startup and load it into the registry. Once it's in the registry, you can plug the dongle in anyttime. Once this Another trick is to view Windows Parallels in the "single window" view. This reveals a set of icons in the bottom RHS of the windows view. Once this is done, select the USB icon, click, and be sure that HASP 2.17 is checked. This will force the dongle to register under the Windows Parallells OS. Although we do not formally support GWB for the Mac platform, and do not have a Mac machine in-house for testing, we are more than happy to post other users experiences with GWB on this platform. Regards, Tom Meuzelaar RockWare, Inc.

Hi Lou: Let me see what I can find out. Regards, Tom Meuzelaar RockWare, Inc.

Hello: You did not attach your revised database- can you attach it, and tell me which 3 phases you added so that I can take a look? Regards, Tom Meuzelaar RockWare, Inc.

Dear Vincent: Thanks for your post. There is currently no provision for custom temperature dependency on Pitzer virial coefficients in GWB. I will add this to the list of feature requests- this has been requested at least one time by another user. However, implementing this would not be trivial, so I don't expect you'll see this feature anytime soon. Regards, Tom Meuzelaar RockWare, Inc.

Hello: I don't believe that any of the thermo databases contain Schwertmannite- you'll need to look for solubility product data in the literature and add this mineral manually to one of the databases. All of the databases contain ferrihydrite: In the default LLNL database (thermo.dat) it is called Fe(OH)3(ppd) In the extended LLNL database (thermo.com.v8.r6+.dat) it is called Fe(OH)3 In the Minteq database (thermo_minteq.dat) it is called Ferrihydrite In the PHREEQC (thermo_phreeqc.dat) and WATEQ (thermo_wateq4f.dat) databases it is called Fe(OH)3(a) Regards, Tom Meuzelaar RockWare, Inc.

Dear GWB Users: We have released GWB 8.0.10, which addresses the following issues: Significant improvements to the functioning of the Map View and Animation features in Xtplot Fixes a problem saving datasheets in GSS when TDS is in non-standard units Corrects intermittent problems plotting large numbers of scatter data points Fixes an issue pasting plot legends into PowerPoint 2010 All current GWB Essentials, Standard and Pro version 8 users can download the GWB 8.0.10 patch here. Please contact me with any questions. Regards, Tom Meuzelaar RockWare, Inc.

Hi Dave: No, you'll just need a single cation exchange database (use IonEx.dat as a template), and make sure that you have exchange reactions for Na <-> K, Na <-> Ca, and Na<->Mg etc. GWB will calculate the distribution of these exchanger sites based on equilibrium with the fluid. As far as solid solutions are concerned, you can find a brief discussion and further references in this thread. Hope that helps, Tom

Thanks Mooketsi: For your H2SO4 run, TDS appears to increase with H2SO4 reacted. Electrical conductivity, however, follows the concentration of the OH- anions and H+ cations, which have stronger conductance values than the major anions and cations. Refer to Standard Methods 2510A for further information. I hope that helps, Tom

Hi Rich: No, I haven't figured out what the data limit is on this yet. If I have a few spare minutes, I'll try to bracket this a bit more. Regards, Tom

Hi Mooketsi: I have your GSS file. Can you attach the React files as well? Regards, Tom Meuzelaar RockWare, Inc.

Hi Denis: It looks like there's a problem with your custom rate law for Analcime. It appears to be handling the condition that the precipitation rate for Analcime = 0 as long as Q/K < 1.03 correctly, but the script stops at 72, at which point your Q/K value = 1.0299, just before precipitation should begin. Another way to confirm this is that if you switch from a custom rate law to the built-in rate law (using all of your input variables), the script converges and precipitates kinetically. If all that your script does is establish a minimum Q/K value for Analcime precipitation to begin, I'm wonder if you can use the built-in rate law and critical saturation index setting instead. Also, you have a temperature dependent rate law for both your glass and Analcime, but T never varies in your model- I assume this is for future polythermal simulations? Regarding the two other questions you asked in your email: Yes, if you enter a kinetic mineral in your Reactants tab, GWB will ignore suppression, since you are invoking it's presence in the model kinetically You should use the File - Change working directory setting to establish the default directory for all input and output files Hope that helps, Tom Meuzelaar RockWare, Inc.

Hi Mooketsi: Hard to tell without being able to look at your scripts. Can you attach the CO2 and HSO4 model scripts, any custom databases, and a quick summary of what behavior you expect in both cases? Regards, Tom Meuzelaar RockWare, Inc.

Dave: It was pointed out to me that your original question may have been referring to the equilibrium (or post-speciation) occupancy of cations on the clay. If this is the case, this is simply determined via equilibrium of the exchange sites with the fluid based on the selectivity coefficients for individual cations in the database, as well as the CEC and total rock mass. Hope that clarifies things a bit more. Regards, Tom Meuzelaar RockWare, Inc.

Rich: As a follow-up, this appears to be a bug tied to the number of samples in the GSS dataset, as the scatter points plot fine when I reduce the GSS dataset that you provided. We'll get this address in the next patch, GWB 8.0.10. Regards, Tom

Rich: Turns out I was wrong in saying there is no way to input activity data directly into the GSS spreadsheet. You can do this by creating a new analyte- go to Data -> Add Analytes, and click on the New button. Set category as Species Activities and give the new analyte the same name as the species you are plotting on your Act2 diagram. I've tested this, and it plots fine in Act2. Hope that helps, Tom

Hi T.C.: The problem is that both reactants, the microbial population and your bioacetate mineral, have their own biomass and biomass0 variable. The only way to have one reactant set the value of the 2 variables for the other would be to write a C++ function, and link it into a DLL. I hope that helps, Tom Meuzelaar RockWare, Inc.

Hi Rich: Files received, and problem duplicated. I'll let you know when we figure this out... Regards, Tom

Hi Rich: I've just configured .GSS as an allowable attachment file type on the forum. Can you try your upload once again? If unsuccesful, just email it to me. Also, be sure to include the Act2 file that you are trying to plot scatter data points on... Regards, Tom

Hi Karen: Your model approach should work (this type of problem is more ideally suited for 1D reactive transport, ie. a column model), however, I can give you a couple of suggestions that might advance the model along: Your initial fluid is both in equilibrium with atmospheric oxygen and reduced sulfides, hence it will not equilibrate. Since this is your oxgyenated titration fluid, it does not need to be in equilibrium with the sulfides. I would just define the fluid composition sans minerals, speciate it, and pick it up as reactant If you use the flush method, each successive iteration will completely equilibrate with your sulfide minerals. Does this mimic your experimental conditions, or is it worth considering kinetic dissolution rates for your sulfides? You might consider fixing the fugacity of oxygen in the titrant, since it sounds like oxygen is buffered in your experiment In your Basis, when defining the sulfide+fluid setup, you'll want to do this with minimal initial oxygen. You could even constrain the oxygen concentration via equilibrium with one of the sulfides I hope that helps. You'll find cadmium in the extended LLNL database (thermo.com.v8.r6+.dat). Zn sorption should work as long you have physical ferrihydrite mass present in your system. I'd add these latter elements in one by one- first make sure the dissolution model works, so that it's easier to troubleshoot if your model doesn't converge. Regards, Tom Meuzelaar RockWare, Inc.

fyi, the reason that the GSS data will not work is that there is no way to put activity values directly into the spreadsheet. You can calculate them using the Data - Calculate option, and then they should plot on the Act2 diagram. Regards, Tom

Rich: Disregard the previous reply- attached is a revised working scatter data text file containing only the necessary parts. The legacy scatter data format is rather fickle. A couple of things that I changed: List the Y column data first List the values for aluminium on a log scale, matching that of the diagram Change the header of the aluminium data column to be the name of the component only (ie. not 'log component') I hope that helps, Tom

Hi Rich: Go ahead and email the GSS file to me as well. I'll take a look at both the txt and GSS based scatter dataset. I am at SEG this week, so my response time is slower than usual. Regards, Tom Meuzelaar RockWare, Inc.

Hi Nikolay: You have a custom thermo and surface dataset that I do not have access to, so I cannot completely reproduce your results. However, I am not sure what you mean by "change happening with H and O on reactants tab": you have an O2 concentration of -2.3e-10. I'm not sure about the -.001 moles you are referring to- is this after you run the model? Regards, Tom