Sieverts square root dependence

Fig. 8.9 Hydrogen flux data from a 100 xm thick unalloyed ptdladium foiL Sieverts Law is followed very well, and the square root dependence implies that hydrogen is transported through the membrane in a dissociated form. The membrane, sealed by copper gaskets, was essentially 100% selective towards hydrogen with no leak to helium detected. Permeability at 440°C was 1.9 x 10 mol m- s-> Pa- -5...

Fig. 4.7 (a) Calibration data shown as responses to injections of Hoover a large range of concentrations showing a limit of detection of approximately 100 ppm. (b) Linear calibration plot showing the expected square root dependence as described by Sievert s law and a regression constant of 0.992 (Reprinted with permission from Patton et al. (2010). Copyright 2010 Elsevier)... 

Thus, the mole fraction of atomic nitrogen in the liquid metal phase is proportional to the square root of the partial pressure of molecular nitrogen in the gas phase. This square-root dependency is known as Sievert s law and is found to be valid for diatomic gases like O2, H2, etc. The effect of a chemical reaction on solute distribution between two phases in equilibrium has been considered in great detail in Chapter 5. 

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