Band asymmetry

Band Asymmetry. The peak asymmetry factor AF is often defined as the ratio of peak half-widths at 10% of peak height, that is, the ratio b/a, as shown in Fig. 11.2. When the asymmetry ratio lies outside the range 0.95-1.15 for a peak of k =2, the effective plate number should be calculated from the expression... 

The large increase of the high-frequency bandwidth is but one challenge for the nuclear dynamics theories of hydrogen bonding, which are the subject of this chapter. Other challenges are the band asymmetry, the puzzling appearance... 

We now show that the two-mode model can account for the observed intervalence band asymmetry of the C T ion, the weak tunneling transitions and a Ar value of 0.04 8. We fix the... 

There are band asymmetries and the appearance of subsidiary absorption maxima and minima, such as windows. 

To avoid the distortion produced by the shoulder, the bandwidth at Pt(lll) was analyzed at two-thirds of the peak height (AV2/3). The results are plotted in Fig. 54 as a function of potential. The band narrows as the potential increases, going through a minimum at 0.8 V. The dependence of the coverage on the electrode potential is presented in Fig. 55. This Figure shows a maximum adsorption at 0.8 V. Thus the band narrowing can be related to an increase of homogeneous lateral interactions as the adsorbate layer becomes more compact. The band asymmetry (see Fig. 47) indicates a random distribution of the adsorbed ions with low surface mobility [21]. 

Sources of Band Asymmetry and Tailing in Linear Chromatography. 335... 

One empirical model that is widely used for the evaluation of band asymmetry is the exponentially modified Gaussian (EMG) fimction [111-113]. It is the convolution of the unit area Gaussian function and of an exponential decay of unit area. By definition, the convolution of two functions and (f) is the following function... 

Tailing A type of band asymmetry in which the band front is steep and the rear returns only slowly to the base-line. It is often due to a convex upward isotherm. However, a slow kinetics of mass transfer, or an exponential injection profile can also account for this type of profiles. 

Figure 4.2. The number of fish species is plotted against A modal buoyant densities (only species characterized by different modal buoyant densities within a genus were used), B CsCl band asymmetry and C intermolecular compositional heterogeneity of DNAs. D. Plot of CsCl band asymmetry against compositional heterogeneity of DNAs from fishes (four outliers, numbered according to Table 4.2, were not taken into consideration because the anomalous asymmetries were due to satellite DNAs). The correlation coefficient, R, is given. (From Bucciarelli et al., 2002).

A, CsCl band asymmetry,

-po BAC(s), Bacterial Artificial Chromosome(s)... 

Peter R. Griffiths Introduction Surface selection rule Band asymmetry... 

The equilibrium constants increase with increasing pK values of amines. The mean CT band asymmetry (Equation (6)) amounts to 1.17. The complexation brings about a trans-cis isomerization. 

Under non optimal conditions, separations often yield non-symmetrical peaks, i.e., other than Gaussian in shape. Asymmetry can be measured in terms of the band asymmetry factor As, that is calculated from measures taken at 10% of the peak height (see Fig. 3) by dividing the width segment after the peak maximum projection and the width segment before the peak maximum projection. 

If the dipole moment does not change exactly parallel to the a, b, or c axis a mixed contour will result. Band asymmetry can also result from centrifugal distortion. 

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