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Found 2 results

  1. I have read through the available documentation for React and GWB more broadly and am stumped on a topic. I want to create a complex composite rate law for Olivine (Forsterite) dissolution following Wogelius and Walthers (1991). They have a three term rate equations: Rate = 9.07e-12*activity(H+)^0.54 + 5.25e-15 + 2.33e-17*activity(H+)^-0.31 The overall rate is in units mol cm-2 s-1, so to write this complex composite rate law surface and (1-Q/K) terms are needed. None of the documentation I have read explains clearly how to do such a rate law, and you cannot add more than one kinetic mineral term in React. I suspect I just need guidance on how to format this on the command line, so insight for someone more knowledgeable than me would be appreciated.
  2. Hello all, I am attempting to model alteration mineral formation from an ultramafic composition, but cannot get a solution that converges. I have tried changing the parameters in the Config -> Iteration and Config -> Stepping settings, but it still won't converge. The error I get is: N-R didn't converge after 999 its., maximum residual = 2.46e-15, Xi = 0.0000 Largest residual(s): Resid Resid/Totmol Cbasis --------------------------------------------------------- Fe++ -4.405e-20 2.46e-15 1.074e-12 --------------------------------------------------------- My epsilon value is also 1e-11, so not sure why these lesser residuals count as not converging. This is for a planetary application, so the actual fluid chemistry is not constrained. Can someone please give me some advice on what changes should be made to the Basis fluid chemistry to make the solution converge? Or are there any "standard" Basis fluid chemistry packages that I could use to attempt to achieve solution convergence? The current React model is attached. Thank you in advance for your help and advice, it is much appreciated. All the best, Jesse Chassigny_Freshstart_USE_AllMins.rea
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