Dynamic mechanical thermal analysis Extern

Other thermal analysis techniques such as dilatometry in Sect. 4.1 or thermo-mechanical analysis in Sect. 4.5 can also be used to study the time dependence of T. Especially suited for measurement of the frequency response are dynamic mechanic analyses in Sects. 4.5.4 and 4.5.5, and dielectric thermal analyses in Sect. 4.5.6. Although the different techniques respond to different external excitations, the obtained relaxation times are similar, as shown in Fig. 6.117. Over wider temperature... 

The general experimental approach used in 2D correlation spectroscopy is based on the detection of dynamic variations of spectroscopic signals induced by an external perturbation (Figure 7.43). Various molecular-level excitations may be induced by electrical, thermal, magnetic, chemical, acoustic, or mechanical stimulations. The effect of perturbation-induced changes in the local molecular environment may be manifested by time-dependent fluctuations of various spectra representing the system. Such transient fluctuations of spectra are referred to as dynamic spectra of the system. Apart from time, other physical variables in a generalised 2D correlation analysis may be temperature, pressure, age, composition, or even concentration. 

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