Source spectrum

The modulation index is related to the transmission spectra of the gas-filled reference cell, TRef( ), the measurement cell, with its unknown gas concentration, Ty Ca,(/.), and the optical filter, F(/.), all of which are shown in Equation 1. If required, the source spectra can also be taken into account, by using additional spectral functions (although this will usually have little spectral variation over the linewidth of the gas band) ... 

W.A. Hardy, Shot Source Spectra and Bottom Reflectivity Data , TR-179, Hudson Labs, Columbia Univ, Dobbs Ferry (1969)... 

Mossbauer experiments were performed in transmission mode using a calcium stannate source. Spectra were deconvoluted using standard methods to separate contributions from Tin (II) and Tin (IV) peaks. The Mfissbauer spectrum of the cured rubber (see Figure 1) shows the Tin (II) and Tin (IV) oxidation states, with the Tin (IV) species representing approximately 67% of the total tin signal. Overall, the IS/QS values suggest that the Tin (IV) species formed in the rubber is most probably Tin (IV) oxide, Sn02. The presence of some residual unreacted Tin (II) catalyst within the cured rubber is clearly evident. 

UFe(XeF4, SbFj, WFe) + Ha(CH4)/Av Comparison of fluorine sources, spectra Kompa, Gensel, Wanner 1 )... 

Source Spectra courtesy of Sadtler Laboratories and Aldrich Chemical Co. 

Both hard- and soft-source spectra arc uselTil for analysis. The many peaks in a hard-source spectrum provide useful information about the kinds of functional groups and thus structural information about analytes. Soft-source spectra are useful because they supply accurate information about the molecular mass of the analyte molecule or molecules. 

With a more recent source lamp, employed after deterioration of the ones whose spectral output had been thoroughly examined, somewhat different calibration curves were experienced for OH formed in reacting Hj-Og-Ar mixtures in the 1300-1900 K range, and in particular there was a noticeable effect of the initial Hg Og ratio which had not arisen in the earlier work. This is illustrated in Fig. 2.3. Shown for comparison is the previously experienced calibration relationship for comparable temperature and total pressure conditions, which had not been perceptibly dependent upon particular constituents other than the major diluent, argon. Also included, for comparison of gross analytical sensitivities, are representations of particular experience reported for other source spectra and monitoring procedures, as discussed below. 

It is possible in theory to generate an action spectrum which takes into account the effect of incremental monochromatic radiation in excess of the spectral irradiance of a source spectrum. Narrow-band, near-monochromatic radiation might be superimposed over the polychromatic spectrum from a xenon source to obtain radiation spectrally enhanced in any selected waveband. Using a series of interference filters, a series of cut-on filters, and two filtered xenon sources, it should be possible to generate an action spectrum for polymer degradation under spectrally-altered, UV-enhanced (or even visible-enhanced) source spectra. The effective radiation and dose rate in such an experiment can be written as follows ... 

TABLE 5. The selective loss of hydrogen from molecular ion of n-butane (in %, source spectra, FT/ICR, 70 eV) ... 

Meyerson and collaborators labelled different positions with one D atom and measured the probability of losing the label to the neutral fragment. Amir-Ebrahimi and Gaultprepared monolabelled MCH where every position was labelled. The results of the two studies are collected in Table 14. All these data present source spectra results obtained with unit resolution. In parentheses are the results obtained with a... 

The spectrum of the heptyl ion is given in Table 18. The results for the source spectra are obtained from the spectrum of 1-iodo-n-heptane after correction for the fragments containing iodine. Bu" is by far the most abundant ion. The formation of propyl ion in the source might be astonishing, since it does not correspond to Stevenson s rule it could be formed by successive eliminations of two ethylenes, but we will show later... 

For multiple labelling probability for losing one/two/three etc. labels simultaneously. Calculated for source spectra see text and Reference 220. 

IR spectroscopic analysis was used to identify the surface modification of the wool fibres, using a Perkin - Elmo Fourier Transform infirared (FT-IR) spectrophotometer with Golden Gate attenuated total reflection (ATR) attachment. The Raman spectra were measured on die same spectrophotometer equipment with a FT-Raman module with Hd YAG lasa source. Spectra were accumulated fixrni 64 scans at a resolution of 4 cm. An optical bench alignment was performed before each Raman measurranent to ensure that the spectrometer was fine-tuned and the detector signal maximised. 

The test spectra are accompanied by the spectra of calibration sources and background spectra, together with the appropriate documentation. Because measurement of low-activity sources will often be made close to the detector, errors due to true coincidence summing could be expected. Some programs do allow such corrections to be made and to facilitate that point source spectra of a number of nuclides needed to generate a total efficiency calibration are provided. 

Herrmann H, Hoffinann D, Schaefer T, Brauer P, Tilgner A (2010) Tropospheric aqueous-phase free-radical chemistry radical sources, spectra. Reaction kinetics and prediction tools. Chemphyschem ll(18) 3796-3822... 

Source spectra observed in the far field, i.e., several wavelengths away fi om the rupture, depend on the mpture size. Act, the related v p and the ratio between released seismic wave energy s and seismic moment Mq. The scalar seismic moment Mq of a shear mpture is proportional to the constant displacement plateau amplitude o of the radiated source spectmm and defined as... 

Earthquake Magnitude Estimation, Fig. 3 Theoretical source spectra of radiated displacement (fe/t) and velocity amplitudes (right) scaled to seismic moment Mo. respectively seismic moment rate dMo/dt in relation to the praiod ranges within which the lASPEl (2013) standard magnitudes are measured (see section Magnitude Scales and the... 

The most common source spectra model is the model, in which the displacement... 

Castro RR, Anderson JG, Singh SK (1990) Site response attenuation and source spectra of S waves along the Guerrero, Mexico, subduction zone. Bull Seismol Soc Am 80 1481-1503... 

Source spectra are used to identify analytes. Most GC-MS users utilize databases that classify many mass spectra (np to several hundreds of thonsands) and allow the instant identification of the analyzed molecules (as long as they are recorded in the given database). If the stndied molecules were not previously classified, their identification must be carried out by deduction from observed ions. This is often tedious and requires specific training in spectrum interpretation. The MS/MS techniques described below assist in the interpretation of source spectra. They are often essential to elucidate the structure of an analyte. 

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