Uniform illumination

A critical difference between the transient and CW measurements is that while the CW probe source uniformly illuminates the sample, both the transient pump and probe beams have Gaussian distributions. Equation (7.7) can be rewritten for the transient case as ... 

Owing to the planar layer structure of most micro reactors, uniform illumination is yielded in addition, which can be maintained on increasing throughput by numbering-up [6]. Here, the individual reaction units are assembled in parallel again on a plane, but a larger one. 

It is readily apparent that a mask consisting of equal lines and spaces constitutes a diffraction grating and when uniformly illuminated will produce a diffraction pattern similar to that just discussed with an intensity profile depending on the grating period ( ), the wavelength (X) and the position of the image plane. This will be discussed in more detail later. 

In all the materials studied,early photographs show a uniform structure for the exploding wire. A uniform illumination persists for most materials until the beginning of post-dwell conduction, although in AI shortly after expln bright spots and non-unifotm regions of illumination occur... 

Flare, Illumination A flare designed to provide a constant, uniform illumination level on the ground was patented in 1973 (Ref 1). 

This effect is characterized by light-induced formation of a photo-emf in boundary layer-free systems 8>10>. It is necessary for the generation of the Dember emf to have (a) the formation of a concentration gradient of charge carriers resulting from non-uniform illumination, and (b), electrons and holes of different mobilities ... 

To obtain uniform etching over the whole surface (for instance, in order to produce a mirror-smooth surface), irrespective of local properties of the sample. With n-type samples this is achieved by intensive uniform illumination (see, for example, Sullivan et ai, 1963). 

Figure 6 A schematic band diagram (electrical potential energy versus distance) of a conventional p-n homojunction solar cell at equilibrium (left) and at short circuit under spatially uniform illumination (right). The energies of the conduction- and valence-band edges are Ecb and Evb. respectively. EF is the Fermi level at equilibrium and EFn and EFp are the quasi-Fermi levels of electrons and holes, respectively, under illumination.

Another way to achieve uniform illumination is to lower the optical density of the sample by increasing the effective molar volume. Solid solution of an absorbing guest in a transparent host in either a normal crystal or a molecular inclusion compound can achieve this end so can using a pure crystal of a much larger molecule which includes the chromophore of interest [27]. While it is harder to reach high dilution with the latter approach, it has the virtue that the initial compound is a pure crystal and thus better suited for definitive X-ray investigation. 

A saccharimeter of the latest model is shown in Fig. 44 and its optical parts in Fig. 43. It will be seen that it is a double compensation instrument and differs from the preceding only as regards the polariser. The latter, made on Lippich s principle, consists of a system of three prisms and causes the field to be divided into three parts by two vertical lines when the field is not uniformly illuminated, the two outer zones are illuminated equally, but differently from the middle one. 

The apparatus should be tested before use. The zero is first verified and if, when one scale reads 0 and the field is uniformly illuminated, the other scale does not read 0 also, one of the fixed wedges must be carefully... 

Simple compensation (1) The screw of the scale is turned until the field appears uniformly illuminated and by small movements in both senses the exact point is attained at which the separation between the zones of the field is seen either not at aU or as little as possible. The scab... 

That is, except for a small segment of the hemisphere, the patch is uniformly illuminated as shown in Figure 3.16. Given the irradiance, we can now compute the radiance L given off by the patch. For the following calculation, we assume that a < f ... 

The difference between a single point light source above the ground and a uniformly illuminated hemisphere is shown in Figure 3.17. 

Figure 3.16 A tilted patch with uniform illumination for a hemisphere above ground. If the angle between the normal vector of the patch and the vector pointing to the zenith is a, then the patch is uniformly illuminated except for a small segment of the hemisphere above the patch.

Figure 3.17 The radiance given off by a patch illuminated by a point light source is different from the radiance given off by a patch, which is illuminated by a uniformly illuminated hemisphere.

Algorithms for Color Constancy under Uniform Illumination... 

Numerous algorithms have been proposed for color constancy. We now describe in detail how these algorithms work. We also see how the algorithms perform in practice. The performance of the algorithms will be shown on two sample images. One image shows a scene with a uniform illumination and the other shows a scene with a nonuniform illumination. 

ALGORITHMS FOR COLOR CONSTANCY UNDER UNIFORM ILLUMINATION... 

ALGORITHMS FOR COLOR CONSTANCY UNDER UNIFORM ILLUMINATION 109 For large n, we have... 

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