The electrical engineering handbook CH065

... Distribution is the last section of the electrical power system. Figure 65.1 shows the major components of the electric power system. The power plants convert the energy stored in the fuel (coal, ... connects the selected tap to the line to regulate the voltage. The problem with the tap changer is that the lifetime of the switch is limited. This permits on...

Ngày tải lên: 31/12/2013, 21:28

... coefficients in the same manner as the coefficient of utilization. The room position multiplier is a function of the room cavity ratio and of the location in the room of the point where the illumination ... both. b.Reduce the area of high luminance causing the glare condition. c.Increase the angle between the glare source and the line of vision. d.Increase the lumina...

Ngày tải lên: 30/12/2013, 22:33

... tensile stress in the x-direction, for example, will strain the lattice in the xy-plane and destroy the three-fold symmetry, thereby lifting the degeneracy of the energy minima. However, the four-fold ... LLC According to the deformation potential theory, the strain will shift the energy of all the states in a given band extremum by the same amount, i.e., the valley...

Ngày tải lên: 30/12/2013, 22:33

... (52.7) can be solved for g ( k ), then expressions can be obtained for both the E H and the magnetoresistance (the electrical resistance in the presence of a magnetic field). Solutions ... characterization of the latter. Some authors choose to discuss the Hall effect in terms of the Hall angle, f , shown in Fig. 52.1, which is the angle between the net...

Ngày tải lên: 30/12/2013, 22:33

... superconductor. The correlations of the electrons in the superconductor must lower the overall energy of the system or else the material would not be superconducting in the first place. Because the critical ... ␰ from the boundary, the energy of the material is lowered (because it is superconducting), and more than a distance ␭ from the boundary the energy of the ma...

Ngày tải lên: 30/12/2013, 22:33

... G T is the thermal conductance from the element to the environment, t T is the thermal time constant of the element, t E is the electrical time constant of the element, ... element, R G is the electrical resistance across the element, h is the emissivity of the element for the radiation being detected, and A is the sensiti...

Ngày tải lên: 30/12/2013, 22:33

... assumed not to disturb the trapped charge; the received electrical signal is then correlated with the acoustical wave to determine the profile of the trapped charge. Errors in the measurement would ... times at stresses in the vicinity of the operating stress should yield the value of the effective service life under the operating stress. The slope of the line deter...

Ngày tải lên: 30/12/2013, 22:33

... employed. The mercury thermometer was mentioned in the Introduction as a nonelectrical sensor. The most commonly used electrical temperature sensors are thermocouples, thermistors, and resistance thermometers. ... temperature. As the electrons in the metal gain thermal energy, they move about more rapidly and undergo more frequent collisions with each other and the atomic nuclei...

Ngày tải lên: 30/12/2013, 22:33

... data, the same thermal process can be applied while reversing the direction of the bias magnetic field. To read the stored information optically, the Kerr effect is used to detect the presence of these ... another 45 degrees through the Faraday material, and, because its polarization is now 90 degrees from the incident beam, is deflected by the first calcite prism. The four p...

Ngày tải lên: 30/12/2013, 22:33

... on the glass, and the time of arrival of the waves at the receivers is known because the wave velocity is known. The placing of a finger on the glass weakens the signal and the location of the ... the substrate. The Y axis is scanned in the same fashion after the X wave dies out. Then, when the finger touches the substrate, its water content absorbs some of the...

Ngày tải lên: 30/12/2013, 22:33