Bimodal curve

Either bimodal or unimodal distribution curves may result from environmental, dietary, and behavioral factors, the bimodal curve indicating... 

Figure 5. Cumulative distribution curves of dust collected while processing 100% PET. Key O, original bimodal curve d— 1.08 jxm.a = 1.30 n. curve for distribution having the larger diameter as resolved by theTaylormethod(l ) d=2.9fim, 4 /im.

PL emission spectra exhibit characteristic bimodal curves, as shown in Figure 13.2.3, with two peaks at 2.13 eV (580 nm) and 2.88 eV (430 nm). The former is attributed to Mn(II) and the latter to the polymeric species of AA. The latter emission is not attributable to the additives of AA like the polymerization inhibitor. It is particularly noteworthy that the fonner peak, at 2.13 eV, increases with increasing the amount of Mn(II) concentration, at the cost of the latter peak at 2.88 eV, as shown in Figure 13.2.4. This suggests the possibility of energy transfer from the polymeric species to the active center, Mn(II), of the phosphor ZnS Mn. 

The addition of bilirubin or uremic toxin CMPF, which are strongly bound to HSA, alters the shape of the melting curve of serum albumin producing a bimodal curve, and causes a shift of the temperature maximum of the first peak to the right (Fig. 29.2) [7,8]. 

Figure 5. Shrinkage curve for Nunn clay loam mixed with 10 percent sand (data points from [9] with bimodal curve fitting For the wet part of the curve the following values were used for the parameters k. = 0.859, k. = 1.061, n = 1.695 and e = 0.676. For the dry part of the curve the following values were used for the parameters k. = 0.111, k. = 0.082, n = 1.513 and e = 0.495.

Therefore, together all the results summarized in Table 5, clearly demonstrate that, in reality, with homogeneous catalytic systems, polymers with narrow MWD can be prepared provided that polymerization conditions are properly choosen and controlled. In fact, polymers with broad MWD and even with bimodal curves, result... 

Fig. 10.2. The bimodal curve represents the probable distribution of a geochemically scarce metal in the earth s crust. The large peak is the distribution in common rocks, where scarce metals occur not as separate minerals but as atomic substitutes for abundant metals the small peak represents deposits produced by ore-forming processes such as those resulting from the circulation of brines in the crust. Current mining has already reached the point where the distribution curve for easily accessible scarce minerals turns downward. Further reductions in the grade of ore mined will produce declining tonnages of ore and will eventually bring us to a mineralogical barrier — which lies somewhere in the area between the two humps.

Figure 4b presents the concentration dependence of the order parameter for IM-DPhO. In this case we have obtained the bimodal curve with two maximum at 10 and 10 mol/l, where the effect is the same, and co-called dead zone at 5 x 10 -5 x 10 mol/1, within the effect equals to zero. It should be noticed that a polymodal type of dose-effect dependences has been observed for a number of biological active substances effective at ultra-low concentrations [27]. Usually, the bimodal curve is characterized by second maximiun at the effective ultra-low doses - less than 10 "-10 mold [28], In our experiments the second maximiun of parameter S observed at 10 mol/1 IM-DPhO, but as mentioned above the effective concentration of substances in the membranes is in 100 times less than added ones. Thus, the second maximum observed at 10 " mol/1 of IM-DPhO and it can be regarded as substances effective at Ihe ultra-low concentrations. 

Koningsveld and Kleintjens report on spinodal and critical point measurements for polymer mixtures. They point out that complexity of shape is the most striking feature shared by the majority of experimental cloud point curves in polymer mixtures. Curves with a shoulder and even bimodal curves have been reported. More recently spinodal curves obtained by PICS (p. 315) have also shown complicated shapes including evidence of bimodality. ... 

Therefore, in the absence of any external perturbation (shaking, vibration, stirring, etc.), a metastable coexistence curve (or spinodal curve) will be measured. It will lie inside the equilibrium coexistence curve (or bimodal curve) as depicted schematically in Figure 4.35b. The region between the curves represents a region where metastable supersaturated mixtures will exist if significant perturbation is absent. 

Fig. 7 shows the GPC elution curves of poly(St) obtained with various catalysts. The MEK-soluble fraction of polymer obtained with TiClg-(C2Hg)2AlCl catalyst gave a bimodal curve. The peak of lower molecular weight corresponds to that of polymer obtained with TiCl ... 

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