Vd 10[mV] "Drain voltage"
Vga 0[V] "Gate voltage (applied)"
pHb 3 "pH of bulk electrolyte"
T0 25[degC] Temperature
V_therm R_const*T0/F_const "Thermal voltage"
WAg 4.6[V] "Work function of Ag"
Eeq 0.2[V] "Equilibrium potential of reference electrode"
DA 1e-9[m^2/s] "Diffusion coefficient, cation"
DX DA "Diffusion coefficient, anion"
DH 36.3e-4[cm^2/V/s]*V_therm "Diffusion coefficient, H+"
DOH 20.5e-4[cm^2/V/s]*V_therm "Diffusion coefficient, OH-"
c0 0.1[M] "Concentration parameter"
cH_bulk 10^-pHb[M] "Bulk H+ concentration"
cOH_bulk 10^-14[M^2]/cH_bulk "Bulk OH- concentration"
cA_bulk c0+cOH_bulk "Bulk cation concentration"
cX_bulk c0+cH_bulk "Bulk anion concentration"
zA +1 "Cation charge"
zX -1 "Anion charge"
Istr_bulk 0.5*(zA^2*cA_bulk+zX^2*cX_bulk+cOH_bulk+cH_bulk) "Bulk ionic strength"
eps_H2O 78.5 "Relative permittivity of water"
xD sqrt(epsilon0_const*eps_H2O*V_therm/(2*F_const*Istr_bulk)) "Debye length"
xS 0.5[nm] "Stern layer thickness"
epsr_st 11 "Relative permittivity of Stern layer"
Ci_st epsilon0_const*epsr_st/xS "Stern layer capacitance"
h_max 0.1[um] "Maximum mesh element size (electrolyte domain)"
h_max_surf 9.572087e-12[m] "Maximum mesh element size (oxide surface) ~xD/100"
Ka 10^-6[M] "Equilibrium constant"
Kb 100[M] "Equilibrium constant"
Ns 5e14[1/cm^2] "Oxide surface binding site density"
phi2_aprx -0.01[V] "Potential at outer Helmholtz plane (control parameter for 1D approx.)"
rhos0_aprx sqrt(8*R_const*T0*epsilon0_const*eps_H2O*c0)*sinh(phi2_aprx/V_therm/2) "Surface charge density (1D approx.)"
Psi0_aprx phi2_aprx+rhos0_aprx/Ci_st "Potential at oxide surface (1D approx.)"
eNs e_const*Ns "Help variable"
aHs_aprx if(eNs^2>rhos0_aprx^2,(Kb*rhos0_aprx+sqrt((Kb*rhos0_aprx)^2+4*Ka*Kb*(eNs^2-rhos0_aprx^2)))/(2*(eNs-rhos0_aprx)),NaN[M]) "Activity of adsorped H+ on oxide surface (1D approx.)"
pHb_aprx -log10(aHs_aprx/1[M]*exp(Psi0_aprx/V_therm)) "pH of bulk electrolyte (1D approx.)"
ramp 1 "Continuation parameter"