Rotation of charge

The y-dispersion is solely due to water and its relaxational behavior near about 20 GHz. A minor additional relaxation (6) between 3 and y-dispersion is caused in part by rotation of amino acids, partial rotation of charged side groups of proteins, and the relaxation of protein bound water which occurs somewhere between 300 and 2000 MHz. 

Following the wave-mechanical reformulation of the quantum atomic model it became evident that the observed angular momentum of an s-state was not the result of orbital rotation of charge. As a result, the Bohr model was finally rejected within twenty years of publication and replaced by a whole succession of more refined atomic models. Closer examination will show however, that even the most refined contemporary model is still beset by conceptual problems. It could therefore be argued that some other hidden assumption, rather than Bohr s quantization rule, is responsible for the failure of the entire family of quantum-mechanical atomic models. Not only should the Bohr model be re-examined for some fatal flaw, but also for the valid assumptions that led on to the successful features of the quantum approach. 

Fig. 8. Model for Bo-induced rotation of charge involving ground and excited states, shown for a trigonal planar triorganosilyl cation. Both of the shown Si-C

Larmor rotation The circular rotation of charged particles in a uniform magnetic field. Also called cyclotron rotation. 

The value of ap ra is larger the lower the energy of the excited states involving a rotation of charge AE is small), the more asymmetric the distribution of p electrons (the P term is large) and the closer they are to... 

Other relaxation mechanisms come into play when dipole-dipole relaxation is less efficient. The spin-rotation (SR) interaction is important for spin-5 nuclei in smaller molecules, particularly in the gas phase. The nucleus experiences magnetic fields due to the differential rotation of charge with the molecular frame, and fluctuations of these fields, as with collisions, induce relaxation. This mechanism is distinguished by increase in the rate with increase in temperature and with decrease in viscosity, in contrast to the mechanisms depending on molecular tumbling. This is because the mechanism is more effective with increased population of the higher rotational states. The rate depends on the spin-rotation coupling tensor (C) and its anisotropy (as the square) and appropriate moments of inertia (/), values of which may be available from rotational spectroscopy. 

Solar array efficiency depends on its orientation to the sun. The best result is achieved if the array faces the sun at an angle of 90° to S5°. Precise orientation can be achieved either through the rotation of the whole spacecraft, or the rotation of the solar arrays only. To ensure constant electricity flow regardless of changes in spacecraft orientation, solar arrays charge... 

Microwave Hall experiments have been performed in our laboratory.16 They have shown that the mobility of charge carriers in semiconductors can be measured quite reliably even if the semiconductors are only available in the form of a powder. The measurement technique itself is relatively complicated and involves, for example, rectangular waveguides, which can be rotated against each other on opposite sides of the sample to monitor the phase rotation. In the two-mode resonator, two modes of... 

---