On electrostatic induction through solid insulators

The following paper contains an account of a series of experiments on the variation of the capacity of condensers having solid dielectrics with the potential difference and the time. The influence of temperature on the results has also been investigated. It is not proposed to give any detailed account of previous work on this subject here. A very full list of papers is given in a paper by Schweidler entitled “Studien liber die Anomalien im Yerhalten der Dielektrika,” ‘Ann. der Physik,’ No. 14, 1907, p. 711. Let A and B be two guard ring parallel plate condensers, the dielectric in A being air and in B any insulator. Let the two guard rings be permanently connected to earth, and the two small plates permanently connected together. Suppose initially the large plates and small plates are connected to earth, the small plates then disconnected, and then the large plate of the condenser B raised to a potential + V and that of A to a potential — V. After a time t , measured from the instant at which the plates were charged, the total charge on the small plates will be given by the equation (V + e ) C -(V - e ) C' + e C" = q, where C is the capacity of the condenser A, C' that of B, C" the capacity of the backs of the small plates and their connecting wire, and e the potential of the small plates. The charge q will be very small if the dielectric in B is a good insulator, and we may put it equal to k Vc' t , where k is a constant approximately.

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Note on the influence of temperature on the rigidity of metals

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1920.0045 ◽

1920 ◽

Vol 97 (687) ◽

pp. 450-455

Keyword(s):

Temperature Effect ◽

Young’S Modulus ◽

Test Piece ◽

Young's Modulus ◽

Narrow Strip ◽

Influence Of Temperature ◽

Complex Constant ◽

Fine Wire ◽

Influence Of Temperature On ◽

Series Of Experiments

In these ‘Proceedings,’ I described some experiments on the influence of temperature on the value of Young’s Modulus for various metals. The results showed that the more fusible the metal, the greater was the variation of the modulus with temperature, and suggested that, roughly, the decrement of the modulus for a given rise of temperature was equal to the ratio of the modulus at absolute zero to the melting temperature and a constant ( i. e. d M/ dθ = M 0 /( θ n + θ ')). Since Young’s Modulus is a complex constant, involving both rigidity and volume elasticity, it seemed worth while to examine the temperature effect on rigidity alone, and with this object in view I have recently carried out a further series of experiments on most of the metals previously tested. The apparatus used was a torsion-balance, shown diagrammatically in fig. 1. A vertical rod, A, is suspended by a long fine wire, B, and the test piece, C, in the form of a wire or narrow strip of plate, is clamped to the lower end of A, and also to the fixed support, D. The whole of this part of the balance can be immersed in a bath of fluid at any required temperature.

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The effect of temperature on high-resolution TEM image contrast

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139573 ◽

1995 ◽

Vol 53 ◽

pp. 640-641

Author(s):

T. Geipel ◽

W. Mader ◽

P. Pirouz

Keyword(s):

Form Factor ◽

Inelastic Scattering ◽

Accurate Method ◽

Waller Factor ◽

Effect Of Temperature ◽

Specimen Thickness ◽

Influence Of Temperature ◽

Debye Waller Factor ◽

Influence Of Temperature On ◽

Atomic Form Factor

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).

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