Compositional correlations

Pigment color is determined by the ratio of Cd, and Zn or Hg if present, to S and Se in the product and can be changed all the way from primrose to maroon. Mercury substitution for cadmium yields (Cd, Hg)S pigments with ted and maroon shades similar to those obtained with selenium substitution. The Cadmium Association provides the simple diagram given in Figure 5 showing the color and composition correlation. 

Fig. 5. Color and composition correlation of cadmium-based pigments.

Figure 9.2 Mass spectra of the same E. coli strain, JM109, acquired under conditions of (a) high- (-12.5 iJ) and (b) low- (-7 pJ) light intensities. Interval correlation values are shown for the comparison of the two spectra. The composite correlation index value, the product of the 13 interval values, is 0.573.

Figure 9.2 displays a division of the mass range into 13 intervals. After multiplication of all the individual normalized correlation values, the composite correlation index is smaller and the method achieves more selectivity than it would if a single correlation function were calculated over the full mass range. A lower limit of 0.0001 was placed on the value for each normalized interval comparison to prevent the method from generating absurdly low values. These... 

Figure 9.3 Mass spectra of four different E. coli strains (a) AD4, (b) DH5, (c) LE3, and (d) Y10. Composite correlation indexes derived by comparing these spectra to one another are listed in Table 9.1.

TABLE 9.1 Composite Correlation Indexes for Modified Correlation of Spectra in Figure 9.3... 

TABLE 9.2 Composite Correlation Data for the Eight MRSA Isolates of Mass Spectra in Figure 9.5... 

Musto, H., Rodriguez-Maseda, H. and Alvarez, F. (1995) Compositional correlations in the nuclear genes of the flatworm Schistosoma mansoni. Journal of Molecular Evolution 40, 343-346. 

All stereocenters in 1,6-anhydrohexopyranoses are of inverted orientation compared to those in the parent 4Ci(d) or 1C4(l) conformations of the corresponding hexopyranoses for example, see 21, 23, and l,6-anhydro-/J-D-glucopyranose (22). In chemical properties, these compounds resemble to a certain degree the methyl /f-D-hexopyranosides. They are relatively stable in alkaline media, but are readily hydrolyzed by acids. In aqueous acid solution, an equilibrium is established between the 1,6-anhydrohexo-pyranose and the corresponding aldohexose, whose composition correlates with expectations from conformational analysis and calculations from thermodynamic data.121 Extreme values, 0.2 and 86%, are observed respectively with 1,6-anhydro-/f-D-glucopyranose (22) and l,6-anhydro-/f-D-idopyranose (the latter has all hydroxyl groups in equatorial disposition). 

Logue, J.A., A.L. DeVries, E. Fodor, and A.R. Cossins (2000). Lipid compositional correlates of temperature-adaptive interspecific differences in membrane physical structure. J. Exp. Biol. 203 2105-2115. 

Figure 1. Plot of Integrated (M+Ag)+ ion signal for Behenic Acid ratioed to that for Arachidic Acid Langmuir Blodgett monolayers of mixed composition. Correlation Coefficient = 0.9948 13%RSD. Slope = 0.964 (Theory = 1) Intercept = 0.0192 (Theory =0).

Twenty-two coins from the years 217 to 31 B.C. of the Roman Republic were analyzed by X-ray fluorescence for Fe, Co, Ni, Cu, Zn, As, Ag, Sn, Sb, and Pb. No evidence was found for widespread remelting of coins. The early coins are remarkable for their relatively high Co contents. Several coins have exceptionally high Pb, As, or Sb contents. Generally, the compositions of these Roman Republican coins are very different from those of Roman Imperial coins. Although few coins were analyzed, their compositions correlate reasonably well with time. Further analyses are required to determine whether composition varies with denomination and whether coins may be dated to within a few years by their chemical compositions. Microstructures of two Roman Republican coins containing lead are presented. 

Chemical compositions correlate reasonably well with time. 

Additional analyses are required before one may reliably conclude that chemical composition correlates with denomination. There are indications that composition correlates with denomination (e.g., the exceptionally high lead contents of mid-second-century B.C. semisses and asses and the low lead contents of quadrantes). However, larger numbers of coins must be chemically analyzed to obtain a thorough understanding of the Roman Republican copper-based coinage. 

Slag Viscosity/Composition Correlations. Several attempts have been made in the past to define the linear portion of the viscosity/ temperature curve based on the composition of the coal ash. In the mid-1960 s, workers at the British Coal Utilization Research Association (BCURA) developed. two such correlations based on work with British (bituminous) coals, now generally referred to as the Watt-Fereday (4) and S (3) correlations (6). Unfortunately, attempts to apply this correlation to low-rank coal slags, using either ash or slag composition data, have been generally unsuccessful. 

Fife and Xin (35) found that, under PTC conditions, the reaction between benzoyl chloride and a mixture of 1.0 equivalent of sodium p-toluate and 1.0 equivalent of sodium isobutyrate in the presence of 0,1 equivalent of pyridine 1-oxide gave an anhydride product mixture that contained approximately twice as much benzoic p-toluic anhydride as benzoic isobutyric anhydride on a molar basis (equation 7). Therefore, the process must include an important component that selects for the more lipophilic p-toluate ion. The differential partitioning of the competing carboxylate ions at the di-chloromethane-water interface is a reasonable explanation for this observed selectivity, because product composition correlates with the Hansch (39) hydrophobicity parameters for competing carboxylate ions (40). 

Keen M. J., Klein E. M., and Melson W. G. (1990) Ocean ridge basalt compositions correlated with palaeobathymetry. Nature 345, 423 -426. 

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