Magnetic loss factor

Eq. (9.20) shows that, for a small gap and at low field strengths, the ratio (tan 5)/ p of a high-permeability low-loss material is independent of the gap width and is therefore a useful material constant in the pot-core context. It is often referred to as the magnetic loss factor but is clearly quite different in character from the dielectric loss factor (see Section 2.7.2). It indicates that a reduction in permeability due to the introduction or enlargement of a gap is accompanied by a proportionate reduction in tan (5m (or increase in Qm). 

The way in which magnetic loss in a material is expressed depends upon the particular application. For example, in the case of pot cores, when currents are small and hence the flux density is also small (typically less than 1 mT), the loss factor used is (tan <5)//iri or its reciprocal jinQ where Q is the quality factor. 

It is shown (Section 9.1.4) that the loss factor is independent of gaps introduced in the magnetic circuit. In the case of pot cores (Fig. 9.48), where air gaps are introduced both intentionally and because of the imperfect join, the loss factor is a particularly useful parameter. 

Dielectric constant (e ) and dielectric loss factor (e") are the two most important properties, which have a pronounced effect on the effectiveness of microwave processing of a material. The dielectric constant (s ) is a ratio of the permittivity of a substance to the permittivity of free space. The dielectric constant of a material gives the extent the material could concentrate the electric flux. It is an electrical equivalent of the relative magnetic permittivity (Regier and Schubert, 2001 Venkatesh and Raghavan, 2004). 

Loss factor. 2) Volume specific magnetic snsceptibility. 

Fig.4.3-32 Frequency dependence of permeability, (t, and the relative loss factor, /x"/ /xp, for nanocrystalline Fe73.5Cu1Nb3Si15.5B7 and comparable, low remanence soft magnetic materials used for common mode choke cores [3.23]...

Major composition Saturation magnetization 4 , G Curie temperature Tc,K Resonance line width AH,Oq Lande g factor Coercive force H, Oe Dielectric constant Dielectric loss factor tan 5 Dielectric density, g/cm ... 

Major magnetization temperature line width Lande force constant loss factor density,... 

The reflection loss factor is computed by considering the electric, magnetic and plane wave reflection losses separately according to the following set of equations ... 

The resulting overall energy balance for the plant at nominal load conditions is shown in Table 3. The primary combustor operates at 760 kPa (7.5 atm) pressure the equivalence ratio is 0.9 the heat loss is about 3.5%. The channel operates in the subsonic mode, in a peak magnetic field of 6 T. AH critical electrical and gas dynamic operating parameters of the channel are within prescribed constraints the magnetic field and electrical loading are tailored to limit the maximum axial electrical field to 2 kV/m, the transverse current density to 0.9 A/cm , and the Hall parameter to 4. The diffuser pressure recovery factor is 0.6. 

The declared efficiency and power factor of a motor are affected by its loading. Irrespective of the load, no-load losses as well as the reactive component of the motor remain constant. The useful stator current, i.e. the phase current minus the no-load current of a normal induction motor, has a power factor as high as 0.9-0.95. But because of the magnetizing current, the p.f. of the motor does not generally exceed 0.8-0.85 at full load. Thus, at loads lower than rated, the magnetizing current remaining the same, the power factor of the motor decreases sharply. The efficiency, however, remains practically constant for up to nearly 70% of load in view of the fact that maximum efficiency occurs at a load when copper losses (f R) are equal to the no-load losses. Table 1.9 shows an approximate variation in the power factor and efficiency with the load. From the various tests conducted on different types and sizes of motors, it has been established that the... 

The no-load test is a very informative method to determine the no-load current, core and pulsation losses, friction and windage losses, magnetizing current and the no-load power factor. The test also reveals mechanical imbalance, if any, performance of the bearings, vibration and noise level of the motor. 

Aside from the efficiency of the motor itself, energy efficiency is very dependent upon proper sizing. While the efficiency of a motor is fairly constant from full load down to half load, when a motor operates at less than 40 percent of its full load, efficiency drops considerably, since magnetic, friction, and windage losses remain fairly constant regardless of the load. Moreover, the power factor drops continuously as... 

Thus, the magnetization is transferred from the amide proton to the attached nitrogen and then simultaneously to the intra- and interresidual 13C spins and sequential 13C spin. The 13C chemical shift is labelled during /, and 13C frequency during t2. The desired coherence is transferred back to the amide proton in the identical but reverse coherence transfer pathway. The 15N chemical shift is frequency labelled during t3, and implemented into the 13C 15N back-INEPT step. The sensitivity of the HNCOmCA-TROSY experiment is excellent and nearly similar to HNCA-TROSY except for the inherent sensitivity loss by a factor of /2, arising from additional quadrature detection needed for 13C frequency discrimination in the fourth dimension. The excellent sensitivity is due to a very efficient coherence transfer pathway,... 

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