The electrical engineering handbook CH054

... 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

... 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 luminance of the area surrounding the glare ... Ratios .The ability to see details depends on the contrast between the detail and its background. The greater the contrast difference in luminance, the more readily...

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

... Ehrlich A.C. The Hall Effect” The Electrical Engineering Handbook Ed. Richard C. Dorf Boca Raton: CRC Press LLC, 2000 © 2000 by CRC Press LLC 52 The Hall Effect 52.1Introduction 52.2Theoretical ... is (52.11) where the subscript specifies the band number and m i , the effective mass for each band. These masses need not be equal nor the same as the free electron mass...

Ngày tải lên: 30/12/2013, 22:33

... Recall that for type II materials the boundary between the normal and superconducting regions lowers the overall energy of the system. Therefore, the flux in the superconductor creates as many ... side of the expression is the power flowing into the region. By taking the time derivative of the energy density and appealing to Faraday’s and Ampère’s laws to find the time de...

Ngày tải lên: 30/12/2013, 22:33

... 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 determines the exponent n, which ... 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. Erro...

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 ... rotation. Furthermore, the direction of this twist is either clockwise or counterclockwise, depending on the orientation of the perpendicular magnetic moment, which is eith...

Ngày tải lên: 30/12/2013, 22:33

... after the paper and ribbon move together away from the printhead, the partially cooled ink layer adheres better to the paper than © 2000 by CRC Press LLC to the ribbon substrate. The ribbon is then ... length, and l z the distance from the upstream end of the deflection plates to the paper. Drop deflection can be either binary or analog. With the former, the drop either...

Ngày tải lên: 30/12/2013, 22:33

... vehicles, etc. are familiar terms. There is some variation among them relative to the electronics embedded in the systems and the options available to the driver. The same is true for railroads, ... All of these subsystems interact with each other and many also interact with subsystems external to the vehicle. Some of the initial design considerations for vehicles include: •Will...

Ngày tải lên: 30/12/2013, 22:33