the determination of the time of maximum heat flow t max , the intersection of a parallel to the time axis with the heat flow at arbitrarily defined heat flow values (e.g., 1 mW g -1 or 2 mW g -1 ) , the determination of the time when the heat flow is increased by an additional 0.07 mW g -1 (or 0.25 J g -1 h -1 in the paper) relative to the minimum heat flow during the dormant period , the intersection of the tangent to the acceleration phase with the abscissa , and the determination of the time of maximum heat flow by obtaining the maximum of the first derivative of the heat flow curve . Furthermore, an extensive study on the effect of retarders on Portland cement quantitatively relates the induction period to the retarder dosage without describing the exact mathematical method to determine the induction time.