Page:4SIGHT manual- a computer program for modelling degradation of underground low level waste concrete vaults (IA 4sightmanualcomp5612snyd).pdf/133

      n=sol_array[i][j].n;
      m=sol_array[i][j].m;
      temp= pow(cation[i].c[k],(double) m) * pow(anion [j].c[k] (double) n);
      if((sol_array[i][j].s[k]>0.0)$\lor$ ( temp > soLarray[i][j].ksp)) {
        xa=— MIN(cation[i].c[k], anion[j].c[fc])/10.0;
        xb=—xa
        xc=0.0;
        mnbrak(&xa, &xb, &xc, &fa, &fb, &fc, mnifunc, i, j, k);
        tmp = brent (xa,xb,xc,minfunc,TOL,&moles,i,j,k);
        if (fabs(moles) > 0.05)
          moles *= 0.10;    /* no drastic changes */
        if (sol_array[i][j].s[k];-moles < 0.0)
          moles = sol_array [i][j].s[k];   /* insufficient salt */
        if (cation[i].moles[k]+m*moles<0.0)
          moles = -cation[i].moles[k]/m+0.000001; 
        if (anion[j].moles[k]+n*moles<0.0)
          moles = -anion[i].moles[k]/m+0.000001; 
        $\Delta$litre = 0.001 * moles *sol_array[i][j].molar_density/$\Delta X$[k];
        if (litre[k]+$\Delta$<0.0) {
          $\Delta$litre=-litre[k];   /* insufficient  pore space */
          moles = $\Delta$litre * $\Delta X$[k]*1000.0/sol_array[i][j].molar_density;
        }
        cation[i].moles[k]+=m*moles;
        anion[j].moles[k]+n*moles;
        if (Change_Porosity$\equiv$TRUE) {
          litre[k]+=$\Delta$litre;
            sol_array[i][j].s[k]-=moles;
          }
          $\delta$=fabs(moles);
          w_max=MAX($\delta$,w_max);
        }
      }
    }
  }   /* readjust the concentrations */
  $\phi '^{n}$[k]=1000.0*litre[k]*$\delta X$[k]/Vsample;
  litre[k]=MAX(litre[k],0.0001);   /* avoid zero volume problems */
  for (i=0; i < num_cations; i++ )
    cation[i].c[k]=cation[i].moles[k]/(litre[k]*$\delta X$[k]);
  for (j=0; i < num_anions; i++ )
    anion[j].c[k]=anion[i].moles[k]/(litre[k]*$\delta X$[k]);
       /* Determin [OH] and [H] concentration */    /* store old value */
  old_cOH = anion[OH].c[k];
  charge=0.0;
  for (j=1; j < num_anions; j++) charge += anion[j].valence * anion[j].c[k]
  for (j=1; i < num_anions; i++) charge += cation[j].valence * cation[j].c[k]
  anion[OH].c[k]=0.5 *(charge+sqrt(SQR(charge)+4.0*sol_arrary[H][OH].ksp));
  anion[OH].moles[k]=anion[OH].c[k]*litre[k]*$\Delta X$[k];
  if (fabs((anion[OH].c[k]=old_cOH)/old_cOH)>1.00) {
    w_max = 1.0;
    anion[OH].c[k]=0.5 * (anion[OH].c[k]_old_cOH);
    anion[OH].moles[k]= anion[OH].c[k]*litre[k]*$\Delta X$[k];