Retardation of light

The most recently introduced optical teclmique is based on the retardation of light guided in an optical waveguide when biomolecules of a polarizability different from that of the solvent they displace are adsorbed at the waveguide surface (optical waveguide lightmode spectroscopy, OWLS) [H]. It is even more sensitive than ellipsometry, and the mode... 

The phase retardation of light transiting a material to which an electric field has been applied is given by Eq. (6) ... 

OCT uses interferometry and a reflection-based edge-detection algorithm to define the thickness of tlie circumpapiUary RNFL Measures the retardation of light reflected from the birefringent RNFL fibers and provides an estimated RNFL thickness... 

In the same 25-ft tunnel test the so-called smoke development index (SDI) can also be determined. The smoke measurement is based on the percentage of retardation of light passing through the tunnel exhaust stream and detected by a photocell, and then data obtained are converted to the SDI, with red oak flooring set at 100. AC 174 does not specify any particular SDI as the code requirement, but the industry generally considers SDI above 450 as hazardous and not acceptable, particularly for interior flnish. 

Electrical Properties. Polysulfones offer excellent electrical insulative capabiUties and other electrical properties as can be seen from the data in Table 7. The resins exhibit low dielectric constants and dissipation factors even in the GH2 (microwave) frequency range. This performance is retained over a wide temperature range and has permitted appHcations such as printed wiring board substrates, electronic connectors, lighting sockets, business machine components, and automotive fuse housings, to name a few. The desirable electrical properties along with the inherent flame retardancy of polysulfones make these polymers prime candidates in many high temperature electrical and electronic appHcations. 

There is the possibiUty of a chemical reaction between a plastic and a colorant at processing temperatures. Thermal stabiUty of both the polymer and colorant plays an important role. Furthermore, the performance additives that may have been added to the resin such as antioxidants, stabilizers, flame retardants, ultraviolet light absorbers, and fillers must be considered. The suitabiUty of a colorant in a particular resin must be evaluated and tested in the final apphcation after all processing steps to ensure optimum performance. 

When light that has experienced such retardation is viewed by a polarizer oriented at 90° to the original plane of light polarization, the two components of the original light beam interfere with one another. This results in a change in color and intensity of the observed light. Observed colors correspond to different levels of retardation at that point, which in turn correspond to stress levels. 

The tint plate produces a retardation of about 570 millimicrons, so that the yellow components of white light vanish. The resulting colour of violet-red (or sensitive violef) is changed when an extra retardation is introduced by the strained glass. The eye is very... 

This technique is also based on the phenomenon of optical retardation. The transmission, T, of light transmitted through crossed polarizers depends on the birefringence of the sample as ... 

For example, Romero-Rossi and Stone (11), who worked with ZnO, point out that the magnitude and sign of the effect depend on the ratio of the partial pressures of 02 and CO in the reaction mixture (PoJPco)- The magnitude of the positive effect decreases with increase of this ratio, and at a certain value of Po2/Pco the reaction is retarded by light. 

The first correction to this expression arises hecause the transmission of the electric field from one particle to anotiier is not instantaneous, but must occiw attiie speed of light. In electrodynamics diis phenomenon is called a retarded potential. Casimir and Polder[16] have investigated die consequences of this for quantum mechanics. The effect within distances aroimd 10 cm is completely negligible. 

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