Diffusion coefficients oxygen

FIGURE 10.8 Profiles of the relative oxygen diffusion-concentration product across the DMPC bilayer containing 0 (O) and 10mol% zeaxanthin ( ) at 25°C. The approximate locations of nitroxide moieties of spin labels are indicated by arrows. The value of the oxygen diffusion-concentration product in water can be obtained from the oxygen diffusion coefficient and oxygen concentration in water equilibrated with air at 25°C. (From Subczynski, W.K. et al., Biochim. Biophys. Acta, 1068, 68, 1991. With permission.)... 

The material would be expected to be a hole (p-type) semiconductor. However, in this compound the interstitial oxygen ions can diffuse fairly quickly, and the oxygen diffusion coefficient is higher than normal, so that the compound shows both high oxygen diffusivity and electronic conductivity, a situation referred to as mixed conductivity (Section 8.7). 

Oxygen Diffusion Coefficient (D ), Oxygen Surface Exchange Coefficient (Ar), and Oxygen Ionic Conductivity (tr,) of LaMn03-Based Oxides Measured by SIMS Technique... 

Aki pre-exponential factor of the reverse oxygen diffusion coefficient (cm2/sec)... 

Isotopic exchange reaction rates and oxygen diffusion coefficients of Pt/M-CZ, S-CZ and R-CZ at 41 are listed in Table V (Dong et al., 2004a). The surface diffusion rate for R-CZ (Rg) is nearly 4 times larger than the bulk diffusion rate or the equilibrium isotopic exchange rate (R ), while it is... 

Oxygen Diffusion Coefficient in Ce02-Zr02 Oxides... 

Fig. 4. Variation of the oxygen diffusion coefficient D with y in Lai-ySryMnC -s.

Thus, the result obtained for D(y) is due only to a decrease in the concentration of JT ions in the strontium-alloyed samples (some Mn3+ ions change their valence to Mn4+). It will be used below when we discuss the effect of JT deformations on the oxygen diffusion coefficients. 

A correlation was predicted in terms of this model between the behavior of the concentration dependence of the temperature of the JT (or pseudo-JT) structural phase transition and the concentration dependence of the oxygen diffusion coefficient. 

Fig. 55. Variation of oxygen diffusion coefficient with draw ratio. Key as for Fig. 56...

Figure 2.16. Left oxygen diffusion data of various ceria-coniaining materials 1 CeOj. single crystal 2 CeOj poly crystalline sample 3 CeogYojOiv 4 CCo Yo Oig 5 CeO,g 6 Ceo9Cao,0,/ 7 (0.3%)Od doped CcOj 8 Ce02. shaded area corresponds to oxygen diffusion values calculated from ionic conductivity of rare-earth doped ceria CC. M 02.o,. with x 0.2 and 0.3 using Eq. 2.29. Right details of oxygen diffusion coefficients of rare-earth doped ceria with x=0,3 from top to the bottom (M=Eu,Nd.Ho,Gd.Er.Sm,Y.La.Yb,Dy).

Table 2. Oxygen concentrations and oxygen diffusion coefficients in aqueous acid, recast ionomer, and bulk ionomer phases [1].

Figure 3.8 Distribution for the oxygen diffusion coefficient obtained by use of Monte Carlo simulations to assess propagation of errors for Example 3.2. The mean value for the diffusivity was 1.751 X 10 cm s" and the standard deviation was 1.3 x 10 cm s . ...

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