Intensity corrections

Figure 5.4 Resonance Raman spectrum of [Au2(dcpm)2](CI04)2 in acetonitrile solution at room temperature taken with 282.4 nm excitation, after intensity corrections and subtractions of the Rayleigh line, glass bands, and solvent bands. Reproduced with permission from [7a]. Copyright (1999) American Chemical Society.

The global intensity, corrected for the air scattering, can be divided into its components ... 

Fig. 4. Anaerobic titration of xanthine oxidase with xanthine at pH 8.2 with a reaction time of 2 min. at about 20°. The integrated intensity of the Rapid molybdenum EPR signals (in arbitrary units) is plotted against the number of moles of xanthine added per mole of active enzyme. Activity/A4jo for the enzyme samples used was 112 corresponding to an active enzyme content of 57%. Thus the molar ratios of xanthine/total xanthine oxidase have been multiplied by 1.76 to refer to the active form only. Some of the EPR spectra (recorded at about — 130° and 9.3 GHz) are reproduced to show the changes in signal type as the amount of xanthine is increased. (Data re-calculated from ref. 88, with intensities corrected for variations in tube diameter and enzyme concentration calculated in terms of active enzyme.)...

Although simple intensity correction techniques can be used to develop very adequate XRPD methods of quantitative analysis, the introduction of more sophisticated data acquisition and handling techniques can greatly improve the quality of the developed method. For instance, improvement of the powder pattern quality through the use of the Rietveld method has been used to evaluate mixtures of two anhydrous polymorphs of carbamazepine and the dihydrate solvatomorph [43]. The method of whole pattern analysis developed by Rietveld [44] has found widespread use in crystal structure refinement and in the quantitative analysis of complex mixtures. Using this approach, the detection of analyte species was possible even when their concentration was less than 1% in the sample matrix. It was reported that good quantitation of analytes could be obtained in complex mixtures even without the requirement of calibration curves. 

Once the region to be scanned is selected, the pattern can be automatically indexed with a separate window in the software interface (Fig. 6c) permits the user to define the scanning step resolution or the time that the reflection can be measured in accumulation mode. After measurement, all reflections are given with intensities corrected from background. 

M. Kim, H. Chung, Y. Woo and M. Kemper, New rehable Raman collection system using the wide area illumination (WAI) scheme combined with the synchronous intensity correction standard for the analysis of pharmaceutical... 

One particular standardization method, patented by Shenk and Westerhaus in 1989 [112,117], has seen high utility in NIR food and agricultural apphcations. This method involves a wavelength axis shift correction, followed by an intensity correction. More details on the operation of this method can be found in the literature [112], but its basic operations involve the following ... 

Tabulate values of scattered intensity, corrected for the dark current, for each scan and 0 = 30,. .., 150°. Include values for the reference. Correct all readings for differences, if any, in amplifier gain or filters used. Tabulate as in Refs 15, 16, and 41... 

Fig. 13. Measured scattering intensity of HDPE melt. Intensity corrections for air scattering, polarization, absorption, sample geometry and Compton scattering have beat performed...

Fig. 2.9. A Average Raman spectra of hyperplastic (n = 20 solid line) and adenomatous (n = 34 broken line) colon polyps collected ex vivo (power = 200 mW 30-s collection time). B Average Raman spectra of hyperplastic (n = 9 solid line) and adenomatous (n = 10 broken line) colon polyps collected in vivo (power = 100mW 5-s collection time). The spectra have been intensity corrected, wavelength calibrated, and fluorescence background subtracted (modified from [25], with permission)...

Fig. 13.1 Phosphorylated c-Ski expression in cytosolic fraction of cells in post-MI rat heart. In post-MI rat hearts with chronic large myocardial infarction, phosphorylated c-Ski expression was noted in the cytosol of cells populating the infarct scar (predominantly myofibroblasts) and the remnant heart (mixed cytosolic fraction from myocytes and nonmyocytes). Hearts were sampled at different times after surgical ligation of coronary artery occlusion and Western analysis was carried out to assess phosphorylated c-Ski expression. Trends in -fold protein expression (target band intensity corrected for loading) are shown in curves.

Figure 3. Relative intensity corrected for varying exposure time vs. frequency...

Canepa [9] suggested that one of the two molecular forms of acetylcholine bromide reported by Sorum [6, 7] was incorrect. Dunitz [10], on the other hand, observed some unusual systematic absences and suggested that the crystal used was a twinned P2i/c rather than a single P2i specimen. In response to these observations, Svinning and Sorum [11] refined the structure of acetylcholine bromide based on previous photographic intensities corrected for twinning by Canepa, Pauling and... 

Figure 2-10. An energy diagram of an excited and the ground state. A size-correct perturbation theory adds a size-extensive correction to the ground state. It gives the sum of the same size-extensive correction and intensive correction to the excited state...

From the absolute values and internal consistency of ADP, visualized as thermal (or displacement) ellipsoids . These parameters, especially in anisotropic approximation, tend to act as sinks for all kinds of random and (neglected) systematic errors. Thus, for a strongly absorbing crystal (in the absence of intensity correction) the thermal ellipsoids of all atoms will approximate the Fourier image of the crystal s outer shape. An unreasonably small or large... 

Bond, W. L. Equi-inclination Weissenberg intensity correction factors for absorption in spheres and cylinders, and for crystal monochromatized radiation. Acta Cryst. 12, 375-381 (1959). 

Analysis based on relative ion intensities corrected (3) as follows Values of K were not measured, thus precluding third Taw analysis. 

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