It is clear from the results and drawings that the liquid before the addition behaves as (Bingham), but after the addition the value of (tao yield) decreases, which is the point of intersection of the slope with (y axes), which means that the liquid after the addition approaches the Newtonian behavior (as the slope begins to approach zero). The greater the concentration of the added nanomaterials to crude oil, the lower the value of the tao yield, i.e. closer to the Newtonian behavior. What does that mean?