Emittance spectra

Figure 13.11 PA-IR emittance spectra of a polystyrene film recorded at 120°C with acquisition times ranging from 870 to 17.4ms. Reproduced with permission from Ref [37].

Figure 17.6. (a) Emission spectra of a 3-mm-thick polycarbonate sheet made by the TIRES technique and by uniformly heating the sample. A blackbody emission spectrum is shown below for comparison, (fo) Emittance spectra of polycarbonate derived from the upper panel spectra compared to an absorption spectrum of polycarbonate recorded by photoacoustic spectrometry. (Reproduced from [7], by permission of the American Chemical Society copyright 1990.)... 

In these models the emittance is a function of both the transmittance and the reflectance of the sample. The emittance spectrum of an opaque sample (transmittance = 0) is frilly determined by the changes in surface reflectance with fi equency. In semitransparent samples, strong emission bands can exhibit some distortions or false splittings because the reflectance as well as the transmittance is varying strongly where die absorption coefficient is large. These reflectance effects can be removed by ratioing the emission to the emission of a thick sample of the same material ra er than to diat of a blackbody. 

Celsius. The energy distribution of the radiation emitted by this surface is fairly close to that of a classical black body (i.e., a perfect emitter of radiation) at a temperature of 5,500°C, with much of the energy radiated in the visible portion of the electromagnetic spectrum. Energy is also emitted in the infrared, ultraviolet and x-ray portions of the spectrum (Figure 1). 

The optical properties can be tuned by variations of the chromophores (e.g. type of side-chains or length of chromophorc). The alkyl- and alkoxy-substituted polymers emit in the bluc-gnecn range of the visible spectrum with high photolu-inincsccncc quantum yields (0.4-0.8 in solution), while yellow or red emission is obtained by a further modification of the chemical structure of the chromophores. For example, cyano substitution on the vinylene moiety yields an orange emitter. 

The light emitter in Latia luminescence. The purple protein is strongly fluorescent in red. Thus, at first glance, it would appear to be a most probable candidate for the light emitter or its precursor. However, this possibility was ruled out when we found that there is no way to relate the fluorescence of the purple protein to the bioluminescence spectrum. Thus, the luciferase must contain a chromophore that produces the light emitter. 

Laetmogone, 301, 337 Latnpadena, 163, 339 Lampito, 216, 234, 335 Lampteroflavin, 270 Lampteromyces, 267, 270 Lampyridae, 1, 2 See also Fireflies distribution, 2 morphology, 2 Lampyris, 2, 337 Latia bioluminescence, 189 activators and inhibitors, 189 light emitter, 191 luminescence spectrum, 192 reaction scheme, 190 Latia luciferase, 183-189, 343 assay, 184... 

Gamma spectroscopy is a radiochemistry measurement method that determines the energy and count rate of gamma rays emitted by radioactive substances. Gamma spectroscopy is an extremely important measurement. A detailed analysis of the gamma ray energy spectrum is used to determine the identity and quantity of gamma emitters present in a material. 

The available data for deriving dose-response relationships for 144Ce are relatively limited. A complicating feature is that the spectrum of diseases produced is dependent upon the form of the 144Ce entering the body and the resultant radiation dose. This is apparent from data in Table 23 in which several different and competing diseases were produced by inhaled 144CeCl3. Additional factors that confuse the interpretation of internal emitter dose-response studies in laboratory... 

The dianion 117 bonded to enzyme (firefly luciferase) appears to be the emitter in blue-green firefly bioluminescence as the emission spectrum exactly matches the fluorescence of 117, and in an analogous way in the case of red bioluminescence the emitter is 115. 

High-intensity radiation in the visible region of the spectrum is obtained from a simple tungsten light bulb. This bulb is essentially a black-body emitter and the relative intensity of the wavelengths of light emitted depends on the temperature of the tungsten wire as shown below. 

Example D-Glucose may be evaporated into the ion source without complete decomposition as demonstrated by its FI spectrum (Fig. 8.13). FD yields a spectrum with a very low degree of fragmentation that is most probably caused by the need for slight heating of the emitter. The occurrence of ions, m/z 180, and [Mh-H]" ions, m/z 181, in the FD spectrum suggests that ion formation occurs via field ionization and field-induced proton transfer, respectively. However, thermal... 

Example ED from untreated wire emitters in the presence of intentionally added alkali metal salts was used to obtain mass spectra of tartaric acid, arginine, pentobarbital and other compounds. [78,80] Besides [Mh-H]" quasimolecular ions, m/z 175, the FD mass spectrum of arginine exhibits [M+Na], m/z 197, and [Mh-K]", m/z 213, ions due to alkali metal cationization as well as [2M-i-H], m/z 349, cluster ions (Fig. 8.14). [37]... 

Fig. 8.14. The FD mass spectrum of arginine, = 174, desorbed from an untreated metal wire emitter in the presence of alkali ions. Adapted from Ref. [37] by permission. lohn Wiley Sons, 1977.

Complexes containing the 3,5-dinitrosalicylate ion, e.g. [Ln2(C2H202N2)3],- H20 (u = 7 -> 15), and methylsalicylate (MesaP ), e.g. [Ln(Mesal)2(OH)-(H2O)] (Ln = La, Pr, Nd, Sm, Gd, Dy, Er, Yb and have been reported. Tris-salicylaldehydato (said ) complexes, Ln(sald)3 (La, Pr, Nd, Sm, Eu, or Tb) form 1 1 adducts with o-phenanthroline (o-phen), aa -bipyridyl, quinoline, and pyridine. The luminescence spectrum of the Eu " complexes showed that, in the solid state, the symmetrically forbidden electric dipole transition intensity was much enhanced for the o-phen adduct when compared to its salicylate analogue. The simple said" complexes were very poor emitters. 

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