Mathematics The Civil Engineering Handbook

... point called the origin These two lines constitute the coordinate axes; the horizontal line is the x-axis and the vertical line is the y-axis The positive direction of the x-axis is to the right, ... present The values of these units in terms of the corresponding SI units are not exact, since they depend on the values of the physical constants e (for the electronvo...

Ngày tải lên: 09/10/2016, 12:58

... 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 Reduce the area of high luminance causing the glare condition Increase the angle between the glare source and the line of vision Increase the luminance of th...

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 ... permission.) 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...

Ngày tải lên: 30/12/2013, 22:33

... in the 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 electric eld and the ... because of the Lorentz force on the conducting charges and is of just such a magnitude that in combination with the Lorentz force there is no net current in the y direction The...

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 rst place Because the critical ... (53.5) where the left side of the expression is the power owing into the region By taking the time derivative of the energy density and appealing to Faradays an...

Ngày tải lên: 30/12/2013, 22:33

... where 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, R G is the electrical ... constant, T is the absolute temperature, tand is the dielectric loss tangent of the detector material, C E is the electrical capacitance of the element, and C A i...

Ngày tải lên: 30/12/2013, 22:33

... overcompensates for the current due to the deep traps The mobility of the free charge carriers is determined by the depth of the traps, the eld resulting from the trapped charges, and the temperature ... assumed not to disturb the trapped charge; the received electrical signal is then correlated with the acoustical wave to determine the prole of the trapped charg...

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 The...

Ngày tải lên: 30/12/2013, 22:33

... data, the same thermal process can be applied while reversing the direction of the bias magnetic eld To read the stored information optically, the Kerr effect is used to detect the presence of these ... light waves The superposition of these two waves produces a linearly polarized wave The plane of polarization of the resultant wave rotates as one circular wave overtakes th...

Ngày tải lên: 30/12/2013, 22:33

... resistor and the other as a voltage probe where either can function in either role For the Y coordinate value the top layer is the voltage probe, and the voltage is applied by the controller to the bottom ... 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 t...

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 t...

Ngày tải lên: 30/12/2013, 22:33

... know the important aspects of the design which require the knowledge of electrical engineering, the architecture may not be good Given that the implementation of the architecture has to serve ... which the integrated circuits are made One also has to deal with the devices and device physics to make the most efficient transistors of which computing sytems are built The kn...

Ngày tải lên: 31/12/2013, 21:25

... INCREDIBLE CHANGES in the technology associated with electronics over the past three decades have certainly been the driving force for most of the growth in the field of electrical engineering Recall ... years ago the transistor was a novel device and that the majority of electronic systems still used vacuum tubes Then look at the section headings in the following chapter...

Ngày tải lên: 31/12/2013, 21:25