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In an antiferroelectric, unlike a ferroelectric, the total, macroscopic spontaneous polarization is zero, since the adjacent dipoles cancel each other out. Antiferroelectricity is a property of a material, and it can appear or disappear (more generally, strengthen or weaken) depending on temperature, pressure, external electric field, growth ...
For this reason dipole speakers are often used as surround channel speakers, where a diffuse sound is desired to create ambience. A dipole speaker works by creating air movement (as sound pressure waves) directly from the front and back surfaces of the driver, rather than by impedance matching one or both outputs to the air. As a result ...
The bent molecule H 2 O has a net dipole. The two bond dipoles do not cancel. The overall dipole moment of a molecule may be approximated as a vector sum of bond dipole moments. As a vector sum it depends on the relative orientation of the bonds, so that from the dipole moment information can be deduced about the molecular geometry.
The dipoles do not cancel out, resulting in a net dipole. The dipole moment of water depends on its state. In the gas phase the dipole moment is ≈ 1.86 debye (D), [ 11 ] whereas liquid water (≈ 2.95 D) [ 12 ] and ice (≈ 3.09 D) [ 13 ] are higher due to differing hydrogen-bonded environments.
Classically the two waves must have the same polarization to give rise to interference fringes since it is not possible for waves of different polarizations to cancel one another out or add together. Instead, when waves of different polarization are added together, they give rise to a wave of a different polarization state .
One way to obtain the 90° time-phase difference between the two orthogonal field components, radiated respectively by the two dipoles, is by feeding one of the two dipoles with a transmission line which is 1/4 wavelength longer or shorter than that of the other," p.80; or helical elements:
Generally speaking, a large-panel dipole radiator is more demanding of a proper physical placement within a room when compared to a conventional box speaker, but, once there, it is less likely to excite bad-sounding room resonances, and its direct-to-reflected sound ratio is higher by some 4–5 decibels.
This field exerts a torque on the molecular dipoles, causing the directions of the dipole moments to align with the field direction. This change in the molecular dipoles is called oriented polarization and also causes heat to be generated, resulting in dielectric losses (see dissipation factor).