Dispersion theory Terms Links

The original Placzek theory of Raman scattering [30] was in terms of the linear, or first order microscopic polarizability, a (a second rank tensor), not the third order h3q)erpolarizability, y (a fourth rank tensor). The Dirac and Kramers-Heisenberg quantum theory for linear dispersion did account for Raman scattering. It turns out that this link of properties at third order to those at first order works well for the electronically nonresonant Raman processes, but it cannot hold rigorously for the fully (triply) resonant Raman spectroscopies. However, provided one discards the important line shaping phenomenon called pure dephasing , one can show how the third order susceptibility does reduce to the treatment based on the (linear) polarizability tensor [6, 27]. 

A. Surface Free Energies. Surface free energies must dominate any explanation of the adhesion between different phases which are not mechanically linked. Current levels of understanding of adhesiveness are such that actual adhesive strengths are always much less (1-0.1%) than those predicted by thermodynamic analysis, and often there is apparently little correlation between the two. Further refinement of the theory of adhesiveness will require understanding of the importance of flaws in an adhesive joint and of the relative contributions of polar and dispersive Van der Waal s interactions. The following is an analysis of adhesion in terms of surface free energies. 

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