Slope Equation for Self Cleaning Sewage Pipes

Hello all

I was wondering if someone could help shed some light on an equation I found regarding obtaining the slope of sewage pipes in the following paper:-

The paper attached [ATTACH=CONFIG]2604[/ATTACH][ATTACH=CONFIG]2605[/ATTACH][ATTACH=CONFIG]2606[/ATTACH][ATTACH=CONFIG]2607[/ATTACH]

The equation that is quoted to obtain the slope (equation 13) is given as:-

S = 4.65 * N^2 * D^(-4/3) * (q/Q)^(-1/2) * v^2

I was wondering if anyone could figure out what the variables q and Q referred to as these variables are not defined in the paper.

I think Q = Flow Rate but no idea what q refers to.

Can anyone help?

Thank you.

q appears to be a flow rate where on page 4 (q / Q ) appears to be a flow rate ratio.

The document in question should provide declaration for each variable.