Calculation of absorptivities

To verify effectiveness of NDCPA we carried out the calculations of absorption spectra for a system of excitons locally and linearly coupled to Einstein phonons at zero temperature in cubic crystal with one molecule per unit cell (probably the simplest model of exciton-phonon system of organic crystals). Absorption spectrum is defined as an imaginary part of one-exciton Green s function taken at zero value of exciton momentum vector... 

Solving for n by trial and error yields, n = 5.12 5. Calculation of absorption of non-keys. 

Table 7-2. Calculation of Absorption Effects for Sodium Tungstate Solutions...

Under normal conditions (e.g. 10 mA) with the sample in the flame, a global measurement of background absorption and absorption by the element is obtained. However, under strained lamp conditions (e.g. 500 mA), only background absorption is measured. Comparison of both measurements allows the calculation of absorption due only to the analyte. 

The prediction of colour has developed along with molecular orbital theory and the stage has now been reached where reasonably accurate calculations of absorption maxima can be made. A number of methods have been developed to varying degrees of sophistication and generality of application. 

Before we discuss a simple example in the next section, let us summarize the ingredients necessary for the calculation of absorption cross sections ... 

For all investigated systems the equation (7) was used for calculations of absorption band form with gy, g and AH as a fitting parameters. The temperature dependence of these parameters was also determined. 

In this Chapter we describe the extension of the parametric model used for 4f" spectra to calculations of absorption and emission spectra for the 4f 15d configuration. We also illustrate how they can be applied to calculate other properties of interest, such as non-radiative relaxation rates. Finally, we discuss the relationship between parametrized calculations and other approaches, such as ab initio calculations. 

Chapters 2, 3, and 4 review the tools for modeling the performance of three-phase reactors. Chapter 2 evaluates the use of film and penetration theory for the calculation of absorption rate in three-phase reactors. Chapter 3 describes various techniques for characterizing residence time distribution and the models which take into account the macromixing in a variety of three-phase reactors. The concepts described in these two chapters are vital to the simulation of an entire reactor. Chapter 4 illustrates the development of the mathematical models for some important pilot scale and commercial reactors. In Chapter 5 some advantages and disadvantages of three-phase laboratory reactors are outlined. 

Calculation of Absorption Absorption of isotope doses by tiuman subjects was calculated by fecal monitoring (5), that is> by determining the amount of stable isotope ingesteT compared to the amount excreted in the feces in excess of the natural abundance The fractional absorption A (I-F E)/I where I is the amount of isotope ingested F is the total metal in the... 

Two independent calculations of absorption and CD spectra based on the (unrefined) atomic coordinates of the Rps. viridis RC have now been published. Although based on quite different sets of theoretical assumptions, each claims suc-cess in explaining major features of optical spectra, including CD. However, one of them apparently still fails to explain the rotational strength of the long-wavelength Qy band, and the other is possibly too complicated to be completely satisfactory. 

In this paper, we report the TD-DFT simulation of light absorption and luminescence of Aug cluster. The method for calculations of absorption and emission spectra is suggested and the obtained data are analyzed and compared with experimental ones. Aug cluster was chosen for the investigation for the following reasons (i) there are experimental data both on absorption and emission spectra [1] (ii) the geometry of this cluster is reliably well studied. According to available data the most stable isomer has the planar D4h structure. 

Magnetic circular dichroism of 9-methyl-8-azapurine and of 7-, 8-, and 9-methyl-8-azaadenine were better resolved than optical spectra and correlated well with CNDO calculations of absorption maxima the calculated electron densities were also presented. ... 

If the samples to be compared do not have similar scattering coefficients or do not maintain a homogeneous distribution of chromophores through the thickness of the sample, the PC number will not be strictly proportional to chromophore concentration. In such cases, Schmidt and Heitner [3,94,95] propose explicit calculation of absorption and scattering coefficients. This requires measurement of the reflectance of transmitting samples over white and black backgrounds of known reflectance, and additional computation. Eurther details are available in recent reviews [3,94,95]. 

Caution For safety procedures see Appendix 2. For most optical measurements in DACs, it is advantageous to use the largest possible optical angular aperture (f-number) which is compatible with the maximum pressure required. Calculations of absorption coefficients from measurements of the transmittance of crystalline samples must include adequate corrections. 

In processes such as the recovery of gasoline components from natural gas, where only a small fraction of the feed gas is absorbed, calculation of absorption and stripping factors is greatly simplified by assuming L Lo, V = ... 

At angles close to 90° the phase shift is at the value yielding a maximum effective field strength. Calculation of absorption coefficients Ap for p-polarized and As for s-polarized light based on the Maxwell equations, assuming a layer of 1 nm of acetone on a reflecting surface, show basically the close relationship between angle of incidence and phase shift (see Fig. 5.46). 

Consider successively the calculation of absorption processes for intratube absorption, in concurrent spray absorbers, and, finally, in countercurrent plate absorbers. 

The walnut oil used in our study contained 26 6 mg naturally occurring hydroxy fatty acids. After the meal, plasma concentration of these unlabeled hydroxy fatty acids increased by 100% (from 0.54 0.07 to 1.09 0.24 imol/L, P < 0.05). One should realize that the calculation of absorption of the [U- C]-labeled hydroxy- or epoxy-fatty acids is based on the assumption that hydroxy TG are metabolized, transported in chylomicrons, and incorporated into VLDL as any other long-chain fatty acid (37). This may not be true. Less oxidized linoleic acid was incorporated into chylomicrons in CaCo-2 epithelial cells in culture (40). Thus, we may have underestimated the extent of absorption. Nevertheless, an important conclusion is that the more fat that is oxidized, the less there is to be absorbed. 

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