Radiation diffuse source

As the reflected radiation is emitted from the sample in a random direction, diffusely reflected radiation can be separated from, potentially sensor-blinding, specular reflections. Common techniques are off-angle positioning of the sensor with respect to the position(s) of the illumination source(s) and the use of polarisation filters. Application restrictions apply to optically clear samples with little to no scattering centres, thin samples on an absorbing background and dark samples. In either of these cases, the intensity of radiation diffusely reflected off such samples is frequently insufficient for spectral analysis. While dark objectives remain a problem, thin and/or transparent samples can be measured in transmission or in transflectance. 

To determine P), we note that total bound-ray power due to a diffuse source is given by Eq. (4-18) and, like the step-profile above, is proportional to the square of core radius. Consequently, the maximum fraction of initial bound-ray power that can be radiated is given by Eq. (5-55) and is independent of the exponent q, i.e. independent of profile shape. 

Radiation from fibers illuminated by a diffuse source 157... 

RADIATION FROM FIBERS ILLUMINATED BY A DIFFUSE SOURCE... 

The partially diffuse source in Fig. 20-6(a) is modelled as a superposition of (coherent) beams, one of which is shown in Fig. 20-6(b). There is a random relative phase between adjacent beams, and consequently, the total power radiated by the source is found by summing the power in each beam. Assuming that the source is axisymmetric we have... 

In the previous chapter we examined the excitation of modes of a fiber by illumination of the endface with beams and diffuse sources, i.e. by sources external to the fiber. Here we investigate the power of bound modes and the power radiated due to current sources distributed within the fiber, as shown in Fig. 21-1. Our interest in such problems is mainly motivated by the following chapter, where we show that fiber nonuniformities can be modelled by current sources radiating within the uniform fiber. Thus, isolated nonuniformities radiate like current dipoles and surface roughness, which occurs at the core-cladding interface, can be modelled by a tubular current source. 

Diffuse emission Radiation that is extended in angular size on the sky, such as the gamma-ray emission arising from the decay of radioactive nuclei dispersed throughout the interstellar medium. A diffuse source is distinguished from a pointlike or point source of emission that is not resolvable into further individual components given the limited angular resolution of a telescope. 

Fig. 17-4. Radiation heat balance. The 100 units of incoming shortwave radiahon are distributed reflected from earth s surface to space, 5 reflected from cloud surfaces to space, 20 direct reaching earth, 24 absorbed in clouds, 4 diffuse reaching earth through clouds, 17 absorbed in atmosphere, 15 scattered to space, 9 scattered to earth, 6. The longwave radiation comes from (1) the earth radiating 119 units 101 to the atmosphere and 18 directly to space, and (2) the atmosphere radiating 105 units back to earth and 48 to space. Additional transfers from the earth s surface to the atmosphere consist of latent heat, 23 and sensible heat, 10. Source After Lowry (4).

The nondestructive temperature differential test by infrared is used. In this method, heat is applied to a product and the surface is scanned to determine the amount of infrared radiation is emitted. Heat may be applied continuously from a controlled source, or the product may be heated prior to inspection. The rate at which radiant energy is diffused or transmitted to the surface reveals defects within the product. Delaminations, unbonds, and voids are detected in this manner. This test is particularly useful with RPs. 

Compared to a °Co-7 source, the electron accelerator yields an accurately focusable and constant radiation. The °Co-7 source always creates a diffuse radiation, the energy of which decreases with time according to the half-life of the material [40]. 

What is the ultimate fate of the molecular material formed in the envelopes of carbon-rich stars as it heads out into space The dust grains will be processed only slowly by the interstellar radiation held and survive almost intact until they become part of an interstellar cloud. The survival of individual PAHs depends on their size the larger ones withstand radiation much better than do the smaller ones.115 By survival we are referring to the aromatic skeleton the interstellar radiation field will efficiently break H bonds and cause ionization so that unsaturated, ionized PAHs are likely to dominate those found in the diffuse interstellar medium. Such species have been suggested as a source of the DIBs.118,123 Small molecules photodissociate in the interstellar radiation field before the material becomes part of an interstellar cloud. 

In standard FAB, the surface of the matrix solution is depleted of analyte and suffers from radiational damage during elongated measurements. Refreshment of the surface proceeds by diffusion (limited by the viscosity of the matrix) or evaporation. Continuous-flow fast atom bombardment (CF-FAB) continuously refreshes the surface exposed to the atom beam. [107,108] The same effect is obtained in slightly different way by the frit-fast atom bombardment (frit-FAB) technique. [109,110] In addition, both CF-FAB and frit-FAB can be used for online-coupling of liquid chromatography (LC, Chap. 12) [111] or capillary electrophoresis (CE) to a FAB ion source. [112]... 

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