Different oxygen partial pressures

The mathematical model was found to describe well the observed activity increase for numerous mechanical mixtures of a-Sb204/Mo03 at different oxygen partial pressures and temperatures.73... 

When a zirconia electrolyte is exposed on different sides to gases with different oxygen partial pressures a relationship such as shown in Figure 1 is obtained. The voltage, E, developed with this type of galvanic cell is given by the Nernst equation as shown below ... 

Fig. 1.3 Temperature (F) versus composition (O/M) curves at different oxygen partial pressure > PqJ.

Figurel.8 /n s/ tu XPS data of a single crystal ofVaOc (basal surface orientation) heated under different oxygen partial pressures.

Fig. 5.16. AFM images (lxl pm2) of the surface morphology and root mean square value of the surface roughness Rrms for 1pm ZnO films deposited at Ts = 200° C at different oxygen partial pressure...

Fig. 7.18. Temperature dependence of the Hall mobility (top) and of the carrier concentration (bottom) of undoped PLD ZnO thin films on a-plane sapphire grown at different oxygen partial pressures (see legends). Note the different temperature scales. The film grown at highest pressure shows an unusual metal-like temperature dependence of the carrier concentration for T < 90K. By H. von Wenckstern [59]...

Figure 1. X-ray diffraction patterns for deposited films prepared by RF sputtering using pure W metal target with different oxygen partial pressure.

Figure 4.6.1 Equilibrium concentration (mM) of dissolved oxygen in RPMI medium at different oxygen partial pressures (mmHg). Based on data of Oiler et al. (1989) by permission of Journal of Cell Science.

Figure 13.24 shows the calculated surface tension of Si B (left) and Si-C (right) melts. The modeled surface tension and temperature gradient for the Si-O melts at different oxygen partial pressures are shown in Fig. 13.25. The calculation results can reproduce the experimental data [159-163] within their uncertainties.

Figure 4 The ionic current plot as a function of temperature at different oxygen partial pressures (0.05, 0.30, and 1.00 atm). The inset is a plot of the simulated conductivity compared to the EIS experiment [115] (in log(o) in Sm- ) as a function of inverse temperature (in 1000/7). Reprinted from Reference [119], copyright 2008, with permission from Elsevier.

Fig. 1.28. Mass spectra of antimony and antimony oxide cluster distributions synthesized at different oxygen partial pressures in the flow tube reactor presented in Fig. 1.27. (a) oxygen traces only, (b) 4mbar O2, (c) 40mbar O2. The geometric structures shown for the most prominent antimony oxide cluster species in the mass spectra have been determined by quantum chemical calculations (dark spheres, antimony atoms grey spheres, oxygen atoms) [23,163]...

A different oxygen partial pressure was used on the right-hand side. 

Therefore, the output emf, which is equal to the difference of contact potentials difference, appears at the different oxygen partial pressures Pq2 on the opposite boundaries of the solid electrolyte in open circuit (schematically shown in Figure 1.12) ... 

If the SE and RE of the zirconia-based sensor are exposed to different oxygen partial pressures, P02 (gas) and 7 02 (reference), this induces different chemical potentials of oxygen ions in zirconia at the interfaces with gas phases. In order that the electrochemical potential remains constant, the electrical potential has to be different. Therefore, the output emf of the electrochemical cell (3.2), represented as a difference between potentials on the RE and SE, obeys the well-known Nemst s law ... 

Figure 5. Phenol concentration as a function of time obtained in a semibatch slurry reactor at different oxygen partial pressures but constant reaction temperature.

Haila, K.M., Nielsen, B.R., Heinonen, M.I., and Skibsted, L.H. 1997. Carotenoid reaction with free radicals in acetone and toluene at different oxygen partial pressure. Food Res. Technol. 204, 81-87. 

The electrical conductivity of surfaces of /8-carotene and lycopene carotene (175)] in oxygen has been determined at different oxygen partial pressures. 

Figure 2-33. Composition range over which films grown at 800 °C by MOCVD contained the Y-124 phase at different oxygen partial pressures. (From Hayashi et al. [207].)...

SrCoo 5FeOt showed a remarkable structural stability at high temperature and with different oxygen partial pressure. The conversion of methane using this tube was >98%, the selectivity to CO was 90%, and the H2/CO ratio was around 2.0. Some of these reactor tubes have been tested for syngas production up to 1000h. 

During TTM operation, the feed and permeate sides are at different oxygen partial pressures and activities. An equilibrated oxygen activity can prevent build-up of differential strains on the feed and permeate sides of the membrane and minimize or prevent stress-induced failure, especially during heating and cooling cycles, and planned and emergency shutdowns. 

Fig. 2.1-15 Rate of consumption of A as a function of for different oxygen partial pressures (Pqj - 0.2, 0.4, 0.6 from top to bottom, = 1, (cqj = 1, n - 1) according to Equation (2.1-48). With increasing P, Ta ceases to increase because re-oxidation becomes rate-determining.

This working principle is the one in the lambda probes used to control combustion in engines. If the two electrodes are under different oxygen partial pressures, then an electromotive force is produced following the Nemst law (Equation [16.4]). In practical devices, one of the electrodes is in permanent contact with a reference atmosphere (see Fig. 16.2). 

Identical metals in contact with different concentrations In this case, the metal immersed in a dilute solution is dissolved from the electrode and deposited on the electrode immersed in a more concentrated solution. The other type of electrochemical concentration ceU is known as a differential aeration cell. In this case, the electrode potential difference occurs when the electrode is immersed in the same electrolyte with different oxygen partial pressures. Differential aeration initiates crevice corrosion in aluminum or stainless steel when exposed to a chloride environment. 

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