Before revision: For the case of the conduction electrons being the dominant loss, then where is the dielectric's bulk conductivity, is the angular frequency of the AC current i, is the lossless permittivity of the dielectric, and is the lossless capacitance.
After revision: For the case of the conduction electrons being the dominant loss, then where is the dielectric's bulk conductivity, is the angular frequency of the AC current i, lossless permittivity of the dielectric, and is the is the lossless capacitance.