Softening ranges discussion

The spectrum recorded at 230 K was discarded in the fit procedure because above 200 K the effective thickness decreases drastically because of a significant softening of protein-specific modes [16]. From the simultaneous fit of the spectra in the temperature range 3.2-200 K, the Debye temperature was determined as do = 215 K. AEq proved to be a temperature-dependent quantity, which is discussed later (see Sect. 9.4.2). 

Experimental techniques such as those used to measure specific values of viscosity (e.g. softening point) are still in common use, but are not as powerful as those in which a range of viscosities can be measured. Hence, only the Margules (1 to 106 Pa-s), parallel plate (103 to 108), and beam bending viscometers (107 to 1014 Pa-s) will be discussed here. These devices are manufactured and marketed by Theta Industries. 

There are significant differences between the small-strain (i.e., small deformation) and the large-strain behavior of polymers. The small-strain behavior is discussed in Section 1 l.B. It is mainly described by the moduli (or compliances) and Poisson s ratio. An amorphous polymer typically softens drastically as its temperature is raised above Tg, so that its structural rigidity is lost. At the typical time scale of a practical observation, the key indicators of stiffness (the tensile and shear moduli), which decrease very slowly with increasing temperature below Tg, decrease rapidly over a narrow temperature range with further increase in temperature by... 

The simple picture afforded by the wormlike chain model is likely to break down under conditions of extreme deformation, as discussed in Section 9.13.2. The internal organization of dsDNA is likely to have instances where the chain is highly deformed, significantly beyond the range where linear elasticity theory is an adequate description. In addition, the potential for dsDNA to exhibit curvature-induced softening may promote... 

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