Propagation Constant Step Response

The frequency dependence of the propagation constant appears as wave deformation in time domain. This is measured as a voltage waveform at distance X when a step (or impulse) function voltage is applied to the sending end of a semi-infinite line. The voltage waveform, which is distorted from the original waveform, is called step (impulse) response of wave deformation, and is defined in Equation 1.201. 

The reason for the much smaller wave deformation in the aerial modes than that in the earth-return mode is that the conductor internal impedance that contributes mainly to the aerial modes is far smaller than the earth-return impedance mainly contributing to the mode 0. 

Modal step responses of wave deformation for a horizontal line. 

It should be noted that the definition of Equation 1.202 proposed by the author in 1973 is effective only for a semi-infinite line or for a time period of 2t, where t is a traveling time of a line [17,18]. Also, the definition requires a further study in conjunction with the wave equation in time domain, because it has not been given the proof that the earlier definition expresses the physical behavior of the time-dependent characteristic impedance. 

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The gradual accumulation of structures III in the initial stages of the reaction could account for its auto-catalytic character until a "stationary-state" is reached in which the surface of the precipitated polymer available for such association with monomer remains practically constant. A structure such as III could also be responsible for the stereo-control of the propagation step. Indeed, the polymer formed at conversions below 2 per cent exhibits much lower stereoregularity than at higher conversions (see Figure 6). These various peculiar consequences connected with the arizing of structure III will be referred to as "matrix effect". 

Apart from labelled ethene,[ ° l FT synthesis was carried out in the presence of other labelled compounds such as ethanol,larger alkenesi and higher alcohols.Most results indicate that more than one mechanism is responsible for the distribution of radioactivity in the products. Figure illustrates that polymerisation of labelled ethene on Co produced more label in even C-number alkanes up to Cio- Almost constant radioactivities were observed in the >Ce products with added propanol. Smaller products showed more incorporated and the monomethyl-alkanes contained more radioactivity. The authors concluded that these alkenes participate both in chain initiation and chain propagation. Alcohols, in turn, initiated chain growth but did not participate in chain propagation on an industrial Fe catalyst.Neither ethene nor ethanol (or ethene formed by its dehydration) participated in the chain termination step. ... 

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