Transverse Alternating Field

Transversely alternating-field electrophoresis TBP-associated factors Triacyl glycerol Tosyl-arginine methyl ester... 

Transverse alternating field electrophoresis. (Courtesy - Chrambach,... 

Daniel, R, de Waele, E., and HaUet, J.-N. (1993) Optimization of transverse alternating field electrophoresis for strain identification of Leucmostoc oenos. Appl Microbiol Biotechnol 38, 638-641. 

At resonance, the magnetization vector M precesses about the vector B, i of the alternating field according to eq. (1.34). As a result, a component of transverse magnetization My.j rotates in the x y plane at the Larmor frequency v0. If a receiver coil is placed in the x y plane, the rotating magnetic vector Myj induces an electromotive force measurable as an inductance current. This process is called nuclear induction [5, 8]. The orientation of the coil axis will affect the phase relative to B1 i but not the magnitude of the induction current. 

AAS (a) Transverse magnetic field, i.e. the (b) Instruments in which the longitudinal magnetic field is perpendicular to the optical magnetic field is oriented parallel to the optical axis of the spectrometer. The rotating polariser axis of the spectrometer do not require a po-provides alternately p- and s-polarised radiation lariser. when the magnetic field is constant or trans-... 

In practice, mass-selective excitation, so-called resonant excitation, is achieved by applying a transverse electric field alternating at the cyclotron frequency f (cOc = 2nfc) to accelerate the ions. Such a field can be applied by a pair of RF electrodes placed on opposite sides of the orbit. As the ions accelerate, the radius of their orbit increases, and the resulting overall motion is a spiral (Fig. 4.52a)... 

As the name suggests, the in-plane switching (IPS) mode is a method that applies an in-plane transverse electric field that is generated by comb-shaped electrodes placed on the substrate, and the liquid crystal layer is switched in the in-plane direction [67]. The modeling of the IPS mode requires an at least two-dimensional model, for example, with respect to the arrangement of the various comb-shaped electrodes to obtain the two-dimensional distribution of the liquid crystal alignment and the transverse electric field described above. There is no alternative to a simulation to get a realistic model, which is totally different from the case of the TN display described above. 

As witli tlie nematic phase, a chiral version of tlie smectic C phase has been observed and is denoted SniC. In tliis phase, tlie director rotates around tlie cone generated by tlie tilt angle [9,32]. This phase is helielectric, i.e. tlie spontaneous polarization induced by dipolar ordering (transverse to tlie molecular long axis) rotates around a helix. However, if tlie helix is unwound by external forces such as surface interactions, or electric fields or by compensating tlie pitch in a mixture, so tliat it becomes infinite, tlie phase becomes ferroelectric. This is tlie basis of ferroelectric liquid crystal displays (section C2.2.4.4). If tliere is an alternation in polarization direction between layers tlie phase can be ferrielectric or antiferroelectric. A smectic A phase foniied by chiral molecules is sometimes denoted SiiiA, altliough, due to the untilted symmetry of tlie phase, it is not itself chiral. This notation is strictly incorrect because tlie asterisk should be used to indicate the chirality of tlie phase and not tliat of tlie constituent molecules. 

The transverse magnetization and the applied radiofrequency field will therefore periodically come in phase with one another, and then go out of phase. This causes a continuous variation of the magnetic field, which induces an alternating current in the receiver. Furthermore, the intensity of the signals does not remain constant but diminishes due to T and T2 relaxation effects. The detector therefore records both the exponential decay of the signal with time and the interference effects as the magnetization vectors and the applied radiofrequency alternately dephase and re-... 

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