Surface elastic moduli polarization

Polarization in the point dipole model occurs not at the surface of the particle but within it. If dipoles form in particles, an interaction between dipoles occurs more or less even if they are in a solid-like matrix [48], The interaction becomes strong as the dipoles come close to each other. When the particles contact each other along the applied electric field, the interaction reaches a maximum. A balance between the particle interaction and the elastic modulus of the solid matrix is important for the ER effect to transpire. If the elastic modulus of the solid-like matrix is larger than the sum of the interactions of the particles, the ER effect may not be observed macroscopically. Therefore, the matrix should be a soft material such as gels or elastomers to produce the ER effect. 

This paper has dealt exclusively with SAW sensors that exploit the mass sensitivity of the device to achieve chemical vapor detection. Schemes to exploit the SAW sensitivity to coating conductance changes (17) or elastic modulus changes should afford new opportunities for imaginative chemical vapor sensor designs. Finally, the field of liquid phase chemical analysis may also yield to surface acoustic wave devices that utilize plate waves and horizontally polarized shear waves to minimize acoustic losses in the liquid (18). 

The relationship between the mechanical stresses and strains and electrical surface charges and polarization is given by the piezoelectric coefficients d and e. These parameters are defined in terms of the stress elasticity modulus (or = Ex), the electric field strength O (in Vm ) and polarization P (dipole moment per unit volume in C/m ) ... 

This article has investigated the potential of cross-linked polyamides for tribological applications. Results have shown a significant influence of the structural properties decrease in crystallinity, cross-linking particularly within quasi-amorphous or less crystalline ranges and the formation of a three-dimensional network. This shows up in the macroscopic material behavior increased insolubility, increased elastic modulus, particularly in the glass transition region, increased stiffness, brittleness, reduced creep and an increase in surface polarity. 

The disturbance in seawater travels rapidly outward, creating a growing spherical cavity. The traveling gas-liquid interface is known as the detonation front. Seawater is not an ideal elastic solid but has a bulk modulus that is a fxmction of pressure. The seawater as it is compressed becomes stiffen Therefore, the velocity of the outward traveling shock wave is a function of the peak pressure of the new wave. As the wave travels outward, the peak pressure decreases as a negative power of radial distance from the source. The value of the negative power decreases from typically -3 to -1.3 with distance from the source (Kramer et al., 1968 Dobrin, 1976). When the initial positive pressure pulse reaches a free water surface, it is reflected as a pulse of opposite polarity. 

To visualize the elastic properties of crystals it is common to draw a polar diagram with radius vectors of length equal to E (that is the reciprocal of Yj j) in all directions. The endpoints of these radius vectors define the so called elasticity surface of the given crystal. For quartz it is in the form of an oval. The numerical value of Young s modulus for each specified direction may be calculated from Eq. (3.57) and from the transformation equation for s j j. 

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