I don't think these equations can be simplified. You could maybe write them in a different way, for instance collecting terms proportional to T-Tm but that will not lead to any significant simplification. Why do you think it could be simplified? Why would the authors deliberately leave a complicated expression?

Simplifying equations is highly dependent on the specifics of some particular situation. The equations you highlighted are general, hence, that is the simplified form for the most general case. If you have specific values for the coefficients, then it might be possible to simplify the equations. For example, if you know a priori that the coefficient for heat capacity is small, say, two or more orders smaller than the other coefficients, then you might justify removing the whole term that coefficient governs. Another angle of attack are the differentials, where you can either contract based on the expected temperature regime. In other words, you might be able to justify throwing out or disregarding a whole term based upon the expectation that the temperature differential is vanishingly small. Lastly, you might decide to use perturbation expansion theorem, whereby, one expands the differential around some point of interest, plus, since the expansion naturally returns a set of ascending terms in some order, you might further justify ignoring higher order terms, based upon the logic that their contribution would be vanishingly small in that temperature regime, etc... 

So, you can well see that your question is not so straight forward! It is an art to effectively simplify equations for a given set of circumstances.

Can you send me the equations(pdf) to e-mail?, because I cannot download.

e-mail: [email protected]

 I am not a expert, because  I study yet(first year). I will try it.

Hi Luis Please check your inbox I have just mailed you. Thank you for your concern.

Thanks, I will trying it.