Light sources qualitative

Due to diffraction effects of micron-sized mirrors in a regular array, commonly used techniques for surface characterization based on interferometry are inefficient. To overcome the diffraction effects we have developed a novel surface characterization method with an incoherent light source, based on the Foucault s knife-edge test (Zamkotsian and Dohlen, 1999). Since Leon Foucault introduced the knife-edge test in the last century (Foucault, 1859), it has been widely used for testing optical surfaces (see Ch. 3). The test offers a simple way of obtaining easily understandable, qualitative information of the surface shape. 

Optical techniques were developed - both in situ and on line - over a broad range of applications and various types of light sources. Main examples are solids concentration measurements in particle fluidisation [6,7], as well as gas-solid flow [8], or sample composition in dry blending operations, this latter beginning from the pioneering work of Harwood et al. [9] up to more recent advances in this scientific field [10-12], The main interest of these techniques lays in the fact that optical probes are easily available on the market, so that qualitative monitoring of mixers is possible at an industrial scale. However, these probes only provide local information of the mixture (typically 1/40 of a tablet), so that in essence, they still sample the powder flow in a way that may be intrusive and not always representative of the overall stream. 

An optical microscope is a very useful tool for defect observation [64]. The resolution is limited to about 180 nm with a normal white light or down to about 80 nm with a deep UV (DUV) light source and a DUV camera. Therefore, optical microscopes are clearly inferior compared to electron microscopes in resolving the small features printed on the patterned wafers. This is a significant limitation. However, it is important to point out that, in many cases, what matters most is to see the defects not the features where the defects are located. In addition, optical microscopes can observe certain things that SEM cannot Indeed, an optical microscope allows the observation of color variation that qualitatively indicates thickness variation. It also has the... 

FIG. 1 A qualitative comparison of the photo-induced discharge curves for pure PVK and fulierene-doped PVK under the same experimental conditions. A tungsten lamp (50 mW cm ) is used as the light source. 

Above-mentioned facts, caused by CA phototransformations during irradiation by different light sources, have been investigated, using methods of chemical analysis, viscosimetry and spectroscopy, since it is known that phototransformation during irradiation by different light sources, may differ in quantitative and qualitative ratio. Benzalaniline (BA), XXXIV, XXXV, XXXVI, XXXI, XXXII have been used as additives, BA being model compound. 

As in FES, the light source of the spectrometer is nothing other than the sample of which all the atoms have been excited. Qualitative analyses of unknowns can therefore be made. This marks an important difference from atomic absorption in which measurements can only be made for elements for which the instrument has been customized (choice of the hollow cathode lamp). Erom a single run, a multielement analysis can be obtained in strict contrast to AAS. However only elements for which a calibration has been carefully undertaken can really be measured. 

Upon changing the position of the screen with respect to a light source (which corresponds to the change in control parameters), the observed image alters qualitatively. A catastrophe corresponds to a change in the form of a caustic appearing with a change in control parameters (Fig. 8). 

The major hazards associated with lighting involve illumination levels, changes in illumination levels, qualitative aspects of lighting, and flicker of some light sources. Some hazards also involve energy level. 

Composition and/or morphology of many polymers and PMC limit NDT visual inspection to surface and near-surface features. Transparent polymers and semitransparent PMC allow for the detection of inhomogeneities, such as voids, pores, or cracks, as well as qualitative or semiquantitative estimates of fiber volume fraction and/or fiber alignment. Light sources enhance sensitivity in visual through-thickness and surface inspection. 

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