Concentration-difference diagram

Fig. 5.1. Concentration-difference diagram for the measured values used in the Example 5.1 ...

Figure 4 shows the application (6) of potentials to the Pt and Au electrodes of the sandwich (vs. a reference electrode elsewhere in the contacting electrolyte solution) so that they span the E° of the poly-[Co(II/I)TPP] couple (Fig. 4B). There is a consequent redistribution of the concentrations of the sites in the two oxidation states to achieve the steady state linear gradients shown in the inset. Figure 4C represents surface profilometry of a different film sample in order to determine the film thickness from that the actual porphyrin site concentration (0.85M). The flow of self exchange-supported current is experimentally parameterized by applying Fick s first law to the concentration-distance diagram in Fig. 4B ...

Figure 9.8 Simple diagram of mitochondrial H -ion movement and axonal K -ion movement to establish membrane potentials across membranes. Note that H movement from the mitochondrial matrix to the outer surface of the inner membrane requires a specific proton pump that requires energy, which is transferred from electron transfer, whereas the K ion movement occurs via an ion channel with energy provided from the concentration difference of K ions on either side of the membrane (approximately 100-fold). The movement of both the protons and K ions generates a membrane potential. The potential across the membrane of the nerve axon provides the basis for nervous activity (see Chapter 14).

Fig. 6. Temperature-concentration phase diagrams for four PHIC-toluene systems with different molecular weights [64]...

Fig. 5 The temperature-polymer concentration phase diagrams of PEO-PPO-PEO copolymer EO13PO30EO13 aqueous solutions at the absence and presence of a-CD with different a-CD concentrations [70]...

Concentration-Temperature Diagram.—In this diagram the temperatures are taken as the abscissae, and the composition of the solution, expressed in atoms of chlorine to one atom of iodine, is represented by the ordinates. In the diagram, A represents the melting-point of pure iodine, 114°. If chlorine is added to the system, a solution of chlorine in liquid iodine is obtained, and the temperature at which solid iodine is in equilibrium with the liquid solution will be all the lower the greater the concentration of the chlorine. We therefore obtain the curve ABF, which represents the composition of the solution with which solid iodine is in equilibrium at different temperatures. This curve can be followed down to 0°, but at temperatures below 7 9 (B) it represents metastable equilibria. At B iodine monochloride can be formed, and if present the system becomes invariant B is therefore a quadruple point at which the four phases, iodine, iodine monochloride, solution, and vapour, can co-exist. Continued withdrawal of heat at this point will therefore lead to the complete solidification of the solution to a mixture or conglomerate of iodine and iodine monochloride, while the temperature remains constant during the process. B is the eutectic point for iodine and iodine monochloride. 

If all eigenvalues are different, the following equations are valid in the concentration-time diagrams for extrema... 

If at least one of the s parameters differs from zero, neither extrema nor points of inflection are found in concentration-time diagrams. For example, assuming the values p, and p,2 are different from zero, eqs. (2.64) and (2.65) can be solved with respect to t. As soon as the concentrations either reach a minimum or a maximum (index m) one obtains... 

In consequence, one finds, for any component Ai for which exactly two of the parameters differ from zero as the distance between the extrema and the point of inflection within a concentration-time diagram in general. 

For this reason a graph of Aa,/Aa,. versus Aaj../AOj. results in general in a straight line for s = 2. The slope determines 02, the intercept is a,. This restriction is necessary, since concentration difference quotient diagrams (in brief called KDQ-diagrams) can degenerate. 

Consider now the different diagrams shown in Figure 4.2.6. In part (b) of this figure, corresponding to a time ti, where tu > h > 0, a small height of the liquid at the top is clear of any particles. The line AA which separates the clear liquid at the top from the suspension below is a discontinuity in terms of the particle mass concentration in the liquid. 

Figure 4.18 Temperature-concentration phase diagram for sPS/ diphenyl methane. C, and Cj stand for molecular compounds of differing stoichiometry and for solid phases (the former crystallized solvent, the latter to the form of sPS). is the form evidenced...

Figure 10.16 shows the phase diagram of the mean field theory calculations [52]. The vertical axis is temperature and the horizontal axis represents the volume fraction of rod-shaped molecules. The attractive interaction parameter C12 between the liquid crystal and the rod-shaped molecules is 0.3 (Fig. 10.16a) and 0.4 (Fig. 10.16b). The solid line is the coexistence curve and the dotted line shows the NI phase transition. Because of the excluded volume effect, there is a phase separation between an isotropic and a nematic phase (I-i-No) on the high-temperature side in Fig. 10.16. With the decrease of temperature, the concentration difference in the coexistence region of I -1- No is reduced, and triple point of No -1-1 -I-No appears in Fig. 10.16a. On the low-temperature side of the triple point, the nematic phase splits into two nematic phases (No and No ) with different concentrations of liquid crystal molecules.

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