Relaxations overlapping

In microwave dielectric measurements (> 30 GHz) the dieleclric permittivity and dielectric losses for bound and free water show significantly different magnitudes. Thus, in measurements at high microwave frequencies the contribution from bound water in the dieleclric losses will be negligibly small, and the contribution from the free water fraction can be found. In contrast to the above-mentioned procedures used for calculation of bound water from the relaxation spectrum analysis, this approach will not involve analyses of overlapping relaxation processes and can thus easily be applied to microemulsions having a complex relaxation spectrum. 

This consideration about the analysis of overlapping relaxation effects holds for all chemical relaxation methods with pulse shaped perturbations, it is not restricted to the pressure jump. 

In general it is difficult to evaluate two closely overlapping relaxation times unless conditions can be found where the amplitude of one of them is very small or zero. In the present case could in fact be observed with almost no interference by 2 (negligible amplitude) by monitoring the reaction at 420 nm which is close to the isosbestic point of PS and PS. 2 monitored at 470 nm where the extinction coefficiencts of PS and PS2 differ strongly interference by could be minimized by evaluating only the last portion of the relaxation curve. 

Figure 6.14. Application of peak cleaning techniques for the separation of overlapping relaxations (a) technique introduced by Creswell and Perlman (1970), with 7k = 10 °C and Tp = 47 °C (b) variation of TSC spectrum with changes in Tp (between -123 °C and +47 °C in 10° increments). Filled circles correspond to the spectrum recorded with the optimum polarization temperature (rp = -13°C) for p relaxation. [From Kalogeras (2004) reprinted with permission of John Wiley and Sons, Ltd.]...

This is due to the strongly overlapping relaxations. The presentation of both parameters is useful where materials show such differences and may explain why certain results do not reproduce well and indeed whether or not a certain parameter is a good choice for material specification. 

Eln) is characterized by a very broad dielectric loss peak which consists of at least two overlapping relaxation regions sometimes the peak clearly separates into two components, but usually it can be reproduced only by... 

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