Outer-media impedance

2 Outer-Media Impedance Zg 1.2.2.1 Outer-Media Impedance 

The outer media of an overhead conductor are the air and the earth for the conductor is isolated by the air from the earth, which is a conducting medium. Therefore, the outer-media impedance Zg of the overhead conductor is composed of the following two components  

The outer-media impedance of an underground cable (insulated conductor) is the same as the earth-return impedance because the underground cable is surrounded only by the earth  

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In general, the impedance and admittance of a conductor are composed of the conductor s internal impedance Z,- and the outer-media impedance Z. The same is applied to the... 

Using the penetration depth for the earth, the outer-media impedance of an overhead conductor is readily obtained based on image theory. Figure 1.2 illustrates a single overhead conductor and its image ... 

Thus, the outer-media impedance of a single overhead conductor is given by... 

For the multiconductor illustrated in Figure 1.3, the outer-media impedance is obtained in the same manner as Equation 1.15 [6] ... 

In order to analyze the influence of the different loading mechanisms on the QCM response one has to model a dependence of the mechanical impedance Zl or the complex resonance frequency shift on the chemical and physical properties of the contacting mediiun. Various models for the mechanical contact between the oscillating quartz crystal and the outer medium are discussed below. The QCM is now so widely and extensively used that, in the framework of this chapter, it is not possible to review all the available literature. Hence we limited ourselves here to a review of the experimental data and theoretical ideas concerning the studies of structure and interaction at solid-hquid interface. Furthermore, we did not present here studies on... 

In order to analyze the influence of the diflferent loading mechanisms on the QCM response, one has to model a dependence of the mechanical impedance Zout or the complex resonance frequency shift on the chemical and physical properties of the contacting medium. Various models for the mechanical contact between the oscillating quartz crystal and the outer medium are discussed below. 

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