Magnetic shield

Figure 27.3 Three-phase air-cored magnetically shielded reactor...

Any increase in the fundamental value of the current beyond I or a voltage drop across the coil of more than 150% of the reactor voltage (this may occur in the presence of harmonics) may, however, saturate the core and reduce the reactance of the coil. Magnetically shielded reactors therefore have limitations when the system harmonics are high or when linear V-/ characteristics are desirable beyond 150% of the rated fundamental current. 

For the theory of neutralization of the magnetic effect on the conductor in a non-magnetic shielding, refer to the continuous enclosures for isolated phase bus systems discussed in Section 31.2.2. As a result of non-magnetic shielding there will be no saturation of the iron core and the V-I characteristic of the reactor will remain almost linear. 

Coreless, gapped iron core or / with magnetic shielding ... 

It eliminates the proximity effect (extra forces and heating) by providing a magnetic shielding to the supporting and metallic structures in the vicinity. 

It reduces the proximity effects between the main current-carrying conductors of the adjacent phases to almost zero due to magnetic shielding, on the one hand, and large centre spacing, on the other. 

The NMR magnetic shielding for atoms like carbon is affected greatly by what it is bonded to and the type of bond to its neighbor. Use the inner carbon atoms of normal butane as the reference atom and calculate the shift in C isotropic shielding for 2-butene and 2-butyne. Can you explain these shifts as a function of the changing molecular environments ... 

For another dramatic illu.slration of chemical shifts, have. students calculate the magnetic shielding of nitrogen in pyridine and compare it to its saturated cyclohexane analogue. 

Correlations in nuclear magnetic shielding, part I. J. Mason, Adv. Inorg. Chem. Radiochem., 1976, 18,197-228 (99). 

A. Haas and U. Niemann Correlations in Nuclear Magnetic Shielding. Part 1 Joan Mason... 

The Molecular Magnetic Shielding Field Response Graph Illustrations of the Benzene Field ... 

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