you could try to separate the two halves, upper and lower,and multiply by 2 at the end, let's say we take the upper half of the cylinder, then,
z goes from 0 to R*Cos∂ (the angule from Z to R),
if you cand find ρ, then 0<θ<2Pi and 0<∂<Pi/2
and you have the volume for the upper part of the...