Lifetimes compound index

The calculated radiative lifetimes rrad = l/krad of the lowest excited state for several compounds are included in Table 2. For the calculation a refractive index of 1.5 was assumed. 

Moreover, the radiative lifetime is not a constant for a given ion and a given electronic level. Indeed, there is a dependence on the refractive index, as clearly shown by eq. (14), so that transposition of a literature value to a specific compound cannot be made directly, which explains the wide range of rrad values reported for an individual Lnm ion. As an example, reported radiative lifetimes for Er111 range from 3 to 12 ms, even for relatively similar compounds (see table 19 below) Another hypothesis inherent to Judd-Ofelt theory is that 4f functions do not contain contributions from 5d orbitals, which is not quite the case for Pr111 and Tbm for instance. Selected data reported in the literature are listed in table 5. 

Risk Characterization. Once a quantitative exposure assessment has been made, Risk Assistant allows the user to automatically calculate lifetime excess cancer risk and/or a hazard index for toxic non-carcinogenic effects of chronic exposure for any agent included in the toxicity databases which currently include about 300 compounds. The appropriate hazard values (slope-potency factors and reference doses) for the relevant routes of exposure are automatically retrieved from the databases. The uncertainty calculations in the exposure assessment can also be retrieved to assess the range of risks associated with a given exposure situation. 

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