Fluorescence correlation spectroscopy INDEX

Figure 16.44. Correlation between the humification index determined by LIF spectroscopy (Huf) in whole soil samples and the humification index /t465 (Milori et al., 2002) determined by conventional fluorescence in the corresponding humic acid samples. The indexes are expressed as arbitrary units (a.u.) (Milori et al., 2006).

The characterization of additive diffusivity in polymers is an important area of study in order to understand the performance of a material. There has been much work in diffusivity measurement by mapping concentration profiles through various techniques, such as FTIR [2, 3], fluorescence recovery [4, 5], ultraviolet microscopy [6, 7], and refractive index-related optical spectroscopy [8]. The process usually involves preparation of standard samples, and correlation of concentration profiles with a mathematical model that is a function of distance and time. 

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