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The gradient of each properties contribution to the objective function during the first and second iterations were extracted and are displayed in Figure 11. In general, each property contributes largely appears to constrain the different parameters in the same direction, with the exception of XXX.
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b)
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Figure 11. The contribution of each type of property to the gradient of the objective function at iteration 0 when refitting against a) enthalpy of mixing and binary mass density and b) pure density and enthalpy of vaporisation. Solid lines represent the true direction and magnitude of each gradient, while the dashed lines represent the same gradients but which have been normalised to enhance clarity when the magnitude of a gradient is small.
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