liquid_DFRI: Calculate the density fluctuation of the refractive index...

In AlexCast/rho: R Hydrology Optics

Description

This function calculates the density fluctuation of the refractive index (DFRI) for liquids. This is the partial derivative of the squared refractive index with respect to density when keeping temperature (isothermic) or pressure (isobaric) constant.

Usage

liquid_DFRI(n, d)

Arguments

n	Refractive index of the medium (unitless).
d	Density of the medium (kg dm^-3).

Details

Between the different formulations for the DFRI, the formulation of Proutiere et al. (1992) show the best experimental comparison with observed data of scattering, when deriving scattering by pure water from density fluctuations (Zhang et al., 2009). Strictly, the formulation was derived for isothermal conditions, but theory supports that it should be the same as isobaric (at least approximately).

Value

A numeric vector with the partial derivative of the squared refractive index with respect to density (dn^2 / dd, dm^3 kg^-1), with density given in kg dm^-3.

References

Proutiere, A.; Megnassan, E.; Hucteau, H. 1992. Refractive index and density variations in pure liquids: A new theoretical relation. The Journal of Physical Chemistry 96, 3485-3489. DOI: 10.1021/j100187a058

Zhang, X. Hu, L. 2009. Estimating scattering of pure water from density fluctuation of the refractive index. Optics Express 17, 3, 1671-1678. DOI: 10.1364/OE.17.001671

See Also

n_water

Examples

# Water entry on Table II of Proutiere et al. (1992):
liquid_DFRI(1.3330, 0.9982)

AlexCast/rho documentation built on Dec. 14, 2021, 9:47 a.m.