Flux density saturation

Flux density saturation. As field-exciting current is increased, a point is reached where the flux density no longer increases because of iron saturation in the core. Normally the generator rating in kilovoltamperes (kVA) is near this flux saturation point. 

To determine the value of p, the saturation or the B-H curve of the silicon steel being used must be available. Assuming a normal flux density for such a core to be 1 1 wb/ m (see also Section 1.9) and making use of a normal B-H curve as shown in Figure 28.28, the corresponding value of H for a value of B as 1.1 wb/m can be read as 200 A/m,... 

The peak operating flux density (Umax) should never closely approach or enter saturation over the power supply s entire operating range. 

Next refer to the normal magnetization eurves and seleet a value of H (magnetizing foree, oersteds (Oe)) that is below the point on the eurves where the permeability starts to drop due to the saturation of the eore material. From the ehart in figure 3-22 a value of 20 Oe is a good value. Choosing a permeability of 60 yields a reasonably low value of flux density. 

The should be approximately one-half the saturation flux density (5sat) at 100°C. A5inax of 1800 to 2500G (0.18 to 0.25T) is satisfactory. To determine the number of turns on the primary, use Equations 3.36a and 3.36b. 

The power convertor must provide the AC motor with low-harmonic voltage waveform and simultaneously allow the amplitude to be adjusted. This avoids magnetic saturation of the motor as the frequency is adjusted. For constant torque, from maximum speed to base speed, the voltage is adjusted proportional to frequency. Above base speed, the motor is usually operated at constant horsepower. In this region the voltage is held constant and the flux density declines. Also, the convei tor must limit the starting current, ensure operation at favorable slip, and provide a path fitr reverse power flow during motor slowdown. 

A general expression for average void fraction in an adiabatic two-phase flow or in saturated boiling was suggested by Zuber and Findlay (1965). Defining the local superficial velocities, VSG(= Qc/A) and VSL (= QJA), as volumetric flux densities, they assumed the velocity and void distributions to be... 

It is often easy to measure the flux density, e.g., using a flowmeter, and then determine the hydraulic conductivity or diffusion coefficient by dividing the flux by the driving force. One of the most difficult problems is determining how to represent the driving force. The symbol V is called an operator, which signifies that some mathematical operation is to be performed upon whatever function follows. V means to take the gradient with respect to distance. For Darcy s law under saturated... 

Today, magnetic information carriers are widespread, and no other technology can compete in storage density and rate of access to stored data. Further improvement in performance requires the development of new magnetic materials with high saturation magnetic flux density, appropriate coercivity and suitable magnetic characteristics. 

Since the magnetic snsceptibilities of ferromagnetic materials are so high, H << M, and Eq. (6.59) can be simplified. Use this information and your value of Ms to calculate the saturation flux density, Bs-... 

Assume there exists some hypothetical metal that exhibits ferromagnetic behavior and that has a simple cubic structure, an atomic radius of 0.153 nm, and a saturation flux density of 0.76 tesla. Determine the number of Bohr magnetons per atom for this material. 

Facilitated diffusion has certain general characteristics. As already mentioned, the net flux is toward a lower chemical potential. (According to the usual definition, active transport is in the energetically uphill direction active transport may use the same carriers as those used for facilitated diffusion.) Facilitated diffusion causes fluxes to be larger than those expected for ordinary diffusion. Furthermore, the transporters can exhibit selectivity (Fig. 3-17) that is, they can be specific for certain molecules solute and not bind closely related ones, similar to the properties of enzymes. In addition, carriers in facilitated diffusion become saturated when the external concentration of the solute transported is raised sufficiently, a behavior consistent with Equation 3.28. Finally, because carriers can exhibit competition, the flux density of a solute entering a cell by facilitated diffusion can be reduced when structurally similar molecules are added to the external solution. Such molecules compete for the same sites on the carriers and thereby reduce the binding and the subsequent transfer of the original solute into the cell. 

Figure 2.6 Air-sea flux densities of N2 (bold lines) calculated as F = (0.39ujq ) (SRCair-Cair) (Scn2/660) (Wanninkhof, 1992). SR stands for the N2 saturation ratio and Um stands for the wind speed in a height of 10m. Water temperature and salinity were set to 25° C and 35, respectively. C ir is the equilibrium concentration of atmospheric N2 and was calculated with the equation given by Hamme and Emerson (2004). The dashed lines represent maximum (3110 pmol N m day ) and minimum (161 pmol N m day ) mean N2 fixation rates for the North Atlantic Ocean (Capone et a/., 2005).

Fig. 15. Effect of the pH of the bath on the deposition rate, phosphorus content, saturation magnetic flux density (BJ, and specific resistance ip) of NiP deposits (T. Osaka et al., 1983 [24]).

Saturation induction (saturation flux density) Bs > 2.0 T (/i well above that... 

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