Absorption coefficient glass

Transmission. The spectral transmission of glass is determiaed by reflectioa at the glass surfaces and the optical absorption within the glass. Overall transmission of a flat sample at a particular wavelength is equal to (1 — R), where P is the absorption coefficient, t the thickness of glass, and... 

Mass absorption increases strongly with the atomic number Z. For the 14.4 keV radiation of Fe, the coefficient follows approximately the relation k. 0.003 from oxygen to krypton. Therefore, organic solvents containing sulfur or chlorine are virtually opaque to the Mossbauer radiation. The sulfur component of a 2 mm layer of dimethylsulfoxide (DMSO) absorbs 70% of the Mossbauer radiation (/ = 1.1 g cm ) [35]. Even worse is dichloromethane (CH2CI2), having an absorption coefficient of 16.83 cm g. A layer of 0.1 g cm , which is only 0.75 mm thick (p = 1.33 g cm ), absorbs about 82% of 14.4 keV radiation. For the same reason, chlorinated polymers (PVC) or glass should not be used for... 

Nonetheless, near-IR is the most widely used IR technique. Less intense water absorptions permit to increase the sampling volume to compensate, to some extent, for the lower near-IR absorption coefficients and the inferior specificity of the absorption bands can for many applications be overcome by application of advanced chemometric methods. Miniaturised light sources, various sensor probes, in particular based on transmission or transflectance layouts, and detectors for this spectral range are available at competitive prices, as are (telecommunications) glass or quartz fibres. 

Absorption measurements, however, on such fatty acid layers mixed with dye molecules which are deposited on glass slides can be used for estimating light absorption in the layer of dye molecules at the crystal surface. A monomolecular layer of dye molecules with an absorption coefficient of 105 M-1 cm-1 as for... 

Changing the base glass caused considerable changes in the -state mean life. To ascertain whether this was the result of variations in spontaneous emission matrix elements or radiationless transition probabilities, the peak absorption coefficient of the 4/9/2 —4F3/2 transition was plotted... 

Figure 35. In (a) and (b) are shown the change in peak absorption coefficient with decay time for 2 and 6 per cent Nd glasses, respectively [from Ref. (130)],...

The QD waveguide transmission measurements were performed at 980 nm and 1550 nm to assess the influence of QDs in the modified waveguide. Interestingly, the absorption coefficients for the QD-doped glass were estimated to be 1.5 cm in the waveguide configuration compared to 2.11 cm in the bulk... 

The discrete ordinates method in a S4-approximation is used to solve the radiation transport equation. Since the intensity of radiation depends on absorption, emission and scattering characteristics of the medium passed through, a detailed representation of the radiative properties of a gas mixture would be very complex and currently beyond the scope of a 3D-code for the simulation of industrial combustion systems. Thus, contributing to the numerical efficiency, some simplifications are introduced, even at the loss of some accuracy. The absorption coefficient of the gas phase is assumed to have a constant value of 0.2/m. The wall emissivity was set to 0.65 for the ceramic walls and to a value of 0.15 for the glass pane inserted in one side wall for optical access. 

FIG. 53. Spectral absorption coefficients of sheet glass at various temperatures and spectral distribution of black body radiation intensity in terms of temperature (after Neuroth, 1952 from Garden, 1968),... 

The transmission and absorption values should be related to particular w avelengths. A plot of transmittance or absorption coefficient in terms of wavelength yields characteristic curves that can be used for describing quantitatively the colouring of glass (see Chapter II, Section 6.6 on coloured glasses). 

FIG. 143. Absorption coefficients of some ionic colourants in glass (after Kingery, 1960). The curve of average sensitivity of the human eye is plotted as the dashed line. 

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