Equilibrium conductivity

Therefore, the activation energy of quasi-equilibrium conductivity changes as a logarithm of concentration of adsorption particles which, when the linear dependence between Nt and P is available, corresponds to situation observed in experiment [155]. We should note that due to small value m function (1.91) satisfactorily approximates the kinetics oit) A - B n(i + t/t>) observed in experiments [51, 167, 168]. Moreover, substantially high partial pressures of acceptor gas, i.e. at high concentrations of Nt expression (1.81) acquires the shape ait) Oait/toc) it,Nty " when t>toc>. This suggests that for... 

Figure 3 The final, equilibrium conductivity of polymerised mixtures of isobutylene and AlBr3 in methyl bromide as a function of the isobutylene concentration [IB]. Each point represents the conductivity resulting from an addition of isobutylene conditions...

While salt is entering the membrane its electrical resistance falls progressively. If the equivalent conductance A of the salt in the membrane may be regarded as constant, which is consistent with the equilibrium conductance data to be discussed later, integration of the local resistance across the thickness of the membrane leads to... 

In conclusion, it can be claimed that a combination of kinetic and equilibrium conductance and membrane potential measurements provides a powerful method for investigating the permselective properties of membranes of low fixed charge density. Such methods should be applicable also to other polymers useful in hyperfiltration if they can be prepared in the form of homogeneous membranes. 

The presence of a maximum on the TSDC curve, which is determined by equilibrium conductivity, was also confirmed in the extensive article by Agarwal (in particular, for chalcogenide glasses). Moreover, it was shown that the TSDC curves may contain more than one peak, the position and amplitude of which depends on... 

Fig. 9. Equilibrium conductance G is plotted as a function of the gate voltage Vg for the electrode separations of 11.7 A (the upper panel, circles) and 13.7 A (the lower panel, squares). Note that G ss 0.94Go at Vg = 0 V and G a 0.25G0 at V 0 V for the...

Fig. 6.6. The temperature dependence of the equilibrium conduction band tail electron concentration at different n-type doping levels (Street 1989).

For the system of BaTi03, the equilibrium conductivity has been the most extensively documented (see, e.g.. Refs. [8, 10, 11]) over the experimentally viable range of —20 < log < 0 at elevated temperatures, although the remaining variable, OxiOj or t] has not been explicitly specified. Figure 10.6a-c shotvs the typical results for the pure [10, 12], acceptor (AlTi)-doped [13], and donor (LaBa)-doped cases [11], respectively. 

It has already been pointed out that the undoped and acceptor-doped BaTi03 have essentially the same defect structure (see Figures 10.3c and/or 10.4b), in the oxygen partial pressure range that is experimentally viable in practice, namely —18 < log aoj < 0. Consequently, the equilibrium conductivities also have the same trend with oxygen activity, as shown in Figures 10.6a and b. Likewise, the relaxation kinetics appears also to be essentially the same [13, 16]. 

It should be noted that in Figure 10.6c, the conductivity for the specimen denoted as Vxi is the equilibrium conductivity of La-doped BaTi03 (nominal composition Bao.99Lao.oiTio.997503), that has an average grain size of 0.86 0.03 pm, and a bulk... 

FIGURE 3.59 The equilibrium conductivity of YBa2CujO as a function of oxygen activity in the... 

The equilibrium conductance of a portion of a system is a measure of its ability to pass gases and vapors and is defined by the pressure drop across that portion of the system. A design that restricts the free motion of the molecules decreases the conductance of the system. Such restrictions can be ... 

Fig. 5.66 High temperature anomalies in the conductivity can be explained with the cube root law. Even the phase transition temperatures themselves are well predicted. The S curve corresponds to the instability during the first order phase transitions. In the case of PbF2 (higher order) the high temperature region is also correctly described. In the other cases a jump characterizes the equilibrium conductivity (1st order phase transition). It occurs at the place on the S curve where the G values of the two phases are identical (see Fig. 5.67) [115].

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