Diffusion constant of oxygen

The diffusion of ions through the polymer matrix has been investigated by Muller. 85 The mobility of the different analytes were found to parallel the diffusion constants of oxygen and ammonia and Table 7.3 describes ion diffusion in several polymers. Accordingly, the development of a polymer matrix for a specific application... 

M" s at 20° and 35°C respectively. To be sure that the protein medium determines the quenching rate and not the temperature dependence of the viscosity of the external water, the diffusion constant of oxygen in water was measured at 20 ° and 35°C. The oxygen diffusion constant does not exhibit real temperature dependence (1.3 x 10 M" ... 

Fig. 6.1. Arrhenius plots of the diffusion constant of oxygen into polyethylene (amorphous and crystalline regions). Several points located at upper left, , marked by a) are based on the results in the paper by Michaels et al. (Ref.

Here, Kj is the equilibrium constant for the jth reaction, is the dimensionless diffusion constant of oxygen, and Pe, the Peclet number, is defined as the ratio of flow to diffusion of oxygen. 

Fig. 4.18 Measurement cell for diffusion constant of oxygen in molten silicon [92].

Table 2 Diffusion Constants of Oxygen (D) in Fig. 10 and Oxygen-Binding and Oxygen-Releasing Rate Constants in the Cobalt-Porphyrin Polymer...

The diffusion coefficient of oxygen in solid silver was measured with a rod of silver initially containing oxygen at a conceim ation cq placed end-on in contact with a calcia-zirconia electrolyte and an Fe/FeO electrode. A constant potential was applied across dre resulting cell... 

The calculated diffusion constants of hydrogen and oxygen atoms are shown in Figure 9. The inset plot shows the equation of state for this isotherm for both L and S simulations. The two results are virtually identical up until 2.6 g/cc. At 34 GPa (2.0 gIcc), the hydrogen atom diffusion constant has achieved values associated with superionic conductivity (greater than... 

In Zone III combustion, the burning rate is determined by the diffusive flux of oxygen through the particle boundary layer. The particle density remains constant throughout burnout and the particle size continually decreases as mass is removed solely from the particle surface (constant-density combustion). 

Mass transfer coefficients In the mass transfer calculations, we need the Henry constant of oxygen in water at 30 °C, which can be evaluated using the relevant correlations presented in Section 1.3.2, Appendix I, and is equal to 34.03. The next parameter we need is the diffusion coefficient of oxygen in water at 30 °C, which can be also found in Table 1.10, Appendix I. The correction for the temperature has been also presented in eq. (1.28) Appendix I. The evaluated diffusion coefficient is 2.5 X 10-9 m2/s. 

S.S. Kristy and J.B. Condon176 found a value of D0 of the order of 10 23 m2 s 1 at 700°C and arrived at the conclusion that this value could not have any noticeable effect on the kinetics of reaction of silicon with oxygen. This is undoubtly the case in view of much greater values of the diffusional constant, ku listed in Table 1.2. From the work of J.A. Costello and R.E. Tressler,177 it can be concluded that the diffusion coefficient of oxygen atoms found by radiotracers becomes comparable with the growth-rate constant of the Si02 layer at temperatures above 1300°C. 

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