The effect of thermal broadening

The effect of thermal broadening can be seen in Fig. 21. As might be expected, the main effect is, in fact, to reduce both the resolution of the spectrum and the overall amplitude as T is increased. 

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In order to calculate the effect quantitatively, explicit expressions are needed for the complex dielectric constant, e, in the presence and absence of an electric field the effects of thermal broadening and inhomogeneities in the electric field may be included at a later point in the theoretical development. 

There are several points to consider when choosing a derivatizing scheme, such as the stability of the derivative to hydrolysis, solvolysis, and thermal decomposition. In addition, if precolumn derivatization is chosen, the derivatization process will alter the chromatographic properties of the analytes, which may result in the need to adopt a different chromatographic mode. Finally, if postcolumn derivatization is chosen, the effects of band broadening and sample loss caused by adsorption and dilution effects should not be overlooked. 

Fig. 2 Thermal FFF elution profiles before (original) and after (corrected) removing the effects of band broadening. With the poly disperse sample (NBS 706), which was analyzed at a flow rate of 0.4 mL/min, the effect of band broadening on the elution profile is minimal. The polydispersity values listed were determined using thermal FFF.

Another unusual feature of CuCl and CuBr is the presence of two Mu centers with nearly identical isotropic hyperfine parameters. One of the centers, Mu7, occurs preferentially at low temperatures but is metastable as evidenced by a thermally activated transition to the second center, Mu77 (see Fig. 13). As the temperature increases, the effects of this transition first appear as an increse of the Mu7 depolarization rate (lifetime broadening). At higher temperatures the transition becomes fast enough so that... 

Similarly, differences in manufacturing substantially affect the DSC melting profile (7). In figure 8 we see thermal curves of nearly identical polyester yarns. Sample one and two are identical in composition--both contain a dyability additive--but were annealed at different temperatures as can readily be seen by the position of the annealing "scars" on the thermograms. The effect of the dyability additive apparently is that it lowers and broadens the melting peak destroying its characteristic first-run, double-peak behavior. 

Hofmann and Thomas (31) have discussed the effect of ion bombardment on thermally grown silicon dioxide. XPS showed that small changes in the surface chemistry were observable. The Si 2p and 0 Is peaks were seen to broaden due to ion damage trtilch presumably Increased bond-angle disorder resulting in charge redistribution. 

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