function beta = calc_beta_z1(params,V,z)
% params: [kf, kr];
R = 8.314;
T = 310;
F = 96485;

% beta = params(:,2).*exp(1*F*V/R/T);
beta = bsxfun(@times, params(:,2)',exp(z*F*V/R/T));

end