Electrical loading interaction

Strong covalent binding potentials determine the distance and direction of atomic binding. Changes in conformation of molecular groups are possible if barriers of rotational potentials can be overcome. The latter determine the intrinsic stiffness of molecular chains or segments. Weak interchain forces arise mainly from dipole interactions. Quantum-mechanical dipolar exchange forces are the main contributors even for nonpolar polymers. For polar polymers, permanent or induced dipoles are also involved they are responsible for dielectric orientational polarization (4). Mechanical loads in polymers are transmitted by covalent and by dipole forces. Electrical loads act directly on dipolar moments. 

When a sample is loaded into the capillary, a transient diastereomer complex may be formed between the sample and the selector. The differing mobilities of the diastereomers in the buffer solution in the presence of an electric field is the reason for the separation. The differences of mobility between the diastereomers are the result of different effective charge sensitivities caused by the different spatial orientations of diastereomers or the specific intermolecular interactions between them. 

The cell membrane is involved in interaction between cells allowing for the flow of ions and electrical impulses between neighboring cells. Cell-to-cell attachment via specific types of specialized junctions allows for the exchange of proteins and ions. One example is that of epithelial cells that exhibit gap junctions, tight junctions, and desmosomes. Some of these junctions can be mechanically active and contract after a mechanical loading. 

The electrical response of a liquid-loaded TSM resonator can be related to the shear mechanical impedance, Z, at the device surface. This mechanical impedance serves as a quantitative measure of the strength of the interaction between the solid and a contacting liquid. 

AW device sensitivity to viscoelastic parameters and electrical pnqieities can be used to advantage in some film characterization techniques. In these situations, a comparison of the AW device response to a model of the AW/thin film interaction is often crucial to the effective evaluation of thin film parameters. These additional interaction mechanisms typically involve changes in both the wave velocity and the wave attenuation for SAW, APM and FPW devices, and changes in both resonant frequency and admittance magnitude in TSM devices. In contrast, mass loading does not contribute to wave attenuation or decreases in admittance since moving mass involves no power dissipation (see Chapter 3). 

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