dielectrics in electric fields (3)

... dielectric constant of many dielectrics depends on the temperature, even allowing for change of state. The theory for calculating the dielectric constant of materials possessing ... ferroelectrics clearly show. Certain polymers such as poly(vinyl chloride) also exhibit a change of slope in ds /dT as T is increased 9 and the interpretation of this data in t...

Ngày tải lên: 21/03/2014, 12:08

... and engineering, including the lastest analysis and modeling techniques. As the editor of the Power Engineering Series, I am proud to include Dielectrics in Electric Fields among ... Power Engineering Series addresses a fundamental element of electrical engineering. Dielectric materials are a key element of electric power engineering, one of the most challen...

Ngày tải lên: 21/03/2014, 12:08

... form given by (1.3). 1 .4.3 FIELD IN A DIELECTRIC DUE TO A CONDUCTING INCLUSION When a conducting sphere is embedded in a dielectric and an electric field E is applied the field ... the individual energy levels transforming into bands is still valid because the interaction between neighboring atoms is still present in the amorphous material just as in...

Ngày tải lên: 21/03/2014, 12:08

... dielectric in alternating fields is examined by the approach of equivalent circuits which visualizes the lossy dielectric as equivalent to an ideal dielectric in series or in ... consistent with dc fields. As the value of n increases s' changes with increasing COT, the curves crossing over at COT = 1. At n=l the change in s' with increasing...

Ngày tải lên: 21/03/2014, 12:08

... Dekker, Inc. All Rights Reserved. c, h- Fig. 4.6 Equivalent circuit for two dielectrics in series for interfacial polarization. R, R * Substituting equations (4.63) and (4.64) in (4.61) ... the interfacial polarization that occurs in the boundaries separating the crystalline and non-crystalline regions, the former region having much higher resistivity. As the frequ...

Ngày tải lên: 21/03/2014, 12:08

... approximately the main chain length may also exist at intervals of a few main chain lengths. The degree of chain branching changes rapidly with density and comparing results obtained by different ... long backfolding; MF migrating fold; P paracrystalline lattice; S straight chains; SB short backfolding; SC single crystals; SF single fibrils (cold stretched); SM...

Ngày tải lên: 21/03/2014, 12:08

... shown in fig. 6.14 21 . The transformation from the time domain to the frequency domain involves the assumption that the current is measured in the interval 0 to infinity, ... Dekker, Inc. All Rights Reserved. (3) Determine (j)(t) from equation (6.58). Fig. 6.12 shows the result of step (1) above in PMMA, using broad band dielectric spectroscopy...

Ngày tải lên: 21/03/2014, 12:08

... in polymers (Mizutani and Ida, 1988, with permission of IEEE). 7.4 CHARGE INJECTION INTO DIELECTRICS Several mechanisms are possible for the injection of charges into a dielectric. ... also inject electrons into the dielectric. We first consider the tunneling phenomenon. 7.4.1 THE TUNNELING PHENOMENON In the absence of an electric field there is a c...

Ngày tải lên: 21/03/2014, 12:08

... ion recombination In considering recombination many of these processes have to be taken into account acting in combination and the decrease of electron density due to recombination ... for generating an ion-pair is a minimum resulting in a minimum sparking potential of the gas. I.2A • 0.8 A C Q 0.6A 0.4A 0.2A 0 ASYMPTOTE -= ORIGIN TANGENT LINE STOLETOW POINT !...

Ngày tải lên: 21/03/2014, 12:08

... amplitude that increases with increasing voltage (Fig. 8.20). (3) The average duration of positive corona pulses tends to increase with decreasing gas pressure and increasing applied voltage. Discharge cell VARIABLE GAIN ... studies on corona discharge continue to draw interest. Corona is a self sustained electrical discharge in a gas where the Laplacian electric fi...

Ngày tải lên: 21/03/2014, 12:08