Region shifted downwards

The titration curves of the dendrimers in the presence of calcium ions are also shown in Fig. 6. In the presence of calcium ions, the titration curve of the G1.5 dendrimer shifted downward, suggesting chelate formation. Both titration curves of the G3.5 dendrimers in the absence and presence of calcium ions are the same, especially in the high pH region. The protonation of the G4.5 dendrimer, however, was promoted in the presence of calcium ions. These results... 

As the feed concentration increases the basis of the triangle and the position of the vertex shifts downwards to the left. The complete separation region becomes narrower and concomitantly also less robust. This implies that when the concentration of the feed is increased, the flow rate ratios in Sects. 2 and 3, as well as the difference (m3 - m2) decrease in consequence (see also Fig. 5). Material balances show that the maximum productivity increases with the feed concentration and asymptotically approaches a maximum value. Hence, when feed concentration increases, productivity improves, but robustness becomes poorer. So the optimum value for the feed concentration of an SMB tends to be defined by a compromise between the opposite needs of productivity and robustness [25,27]. 

Another well-known drawback of the LDA and GGA potentials is their asymptotic behavior. They decay faster than the Coulombic asymptotic behavior vxc(ri)—>1/1 1, Ir —>oo required for the accurate xc potential. In the bulk region the LDA and GGA potentials lack the pronounced atomic shell structure of the accurate potential. The improved potentials should possess these features as well as the proper depth in the bulk region, so they should be shifted downward compared to the LDA/GGA potentials. 

The model coexistence curves for our choice of s — 3.0 are shown in Fig. 4.18. The shaded areas indicate regions of phase coexistence of the confined system. The remarkable ehange of the phase diagram relative to that of the bulk system is caused by the strong confinement together with the strong selectivity of the pore for water. As expected, the critical temperature of the pore fluid is shifted downward. The critical composition has moved toward the water-rich side because of the selective character of the substrates. 

The equilibration proceeds by electron transfer between the semiconductor and the electrolyte. The solution levels are almost intact ( REdox — redox)> since the number of transferred electrons is negligible relative to the number of the redox system molecules (cox and cred). On the other hand, the energy levels of the semiconductor phase may shift considerably. The region close to the interface is depleted of majority charge carriers and the energy bands are bent upwards or downwards as depicted in Fig. 5.60b. 

A recent study of the hydrogenation of propyne on Pd/Zr02 showed residual absorptions from surface species after evacuation. These were attributed to di-cr and propylidyne adsorbed species, but no spectra were illustrated (113). SER spectra of the alkynes but-2-yne, pent-l-yne, and pent-2-yne on a gold electrode have been measured (83). At -0.4 V the nC=C modes are lowered by about 110 cm 1 from the values for the free alkynes. For the alk-2-ynes the shift increases by a further 10 cm"1 upon a change of the potential to +0.4 V. The spectrum of but-2-yne has two principal component bands, at 2134 and 2109 cm-1 in the pC=C region, and also shows a downward shift for the nCH3 modes. 

---