The Thrust(Ct) and Power(Cp) coefficients are dimensionless coefficients which allow you to determine propeller thrust and absorbed power if you know the RPM, Pitch and Diameter and the air density (rho).
The coefficients in the TR-237 Technical Report are determined using Imperial units (Pounds Thrust - Horsepower).
From the Advance graphs, the Thrust and Power may be determined for any airspeed.
On the Advance Curves, the X-axis may be considered airspeed.
The Y-axis gives the value of the coefficients for that airspeed.
On the X-axis the Pitch Speed (RPM X Pitch) is equal to an Advance equal to the Pitch/Diameter ratio.
A prop with a P/D ratio of 0.8 has a Pitch Speed (RPM X Pitch) with an Advance of 0.8.
The Zero Thrust Speed is equal to the Pitch Speed Advance + 0.2.
For a prop with a P/D ratio of 0.8, the Zero Thrust Speed occurs at an Advance of 1.0.