As can be seen, the evaluation of residual stresses and deformations requires the knowledge of a large set of parameters. In particular, three relaxation spectra are needed: the bulk and shear relaxation moduli, as well as the structural relaxation modulus. These three moduli (given by Equation 26–4, Equation 26–5, and Equation 26–9, respectively) involve , and parameters. Next, the reduced time expression shown in Equation 26–7 involves four parameters—namely, the ratio of activation energy to the ideal gas constant, a fractional parameter , a reference temperature , and the absolute zero temperature expressed in the current temperature scale. Finally, liquid and glassy expansion coefficients and are required in Equation 26–10. Note that they can be temperature dependent. Since the evaluation of residual stresses and deformations also involves a cooling phase, the energy equation is also solved, and this requires the knowledge of the density , the thermal conductivity , and the heat capacity .