Semilogarithmic diagram

The AUC is a measure of bioavailability, i.e. the amount of substance in the central compartment that is available to the organism. It takes a maximal value under intravenous administration, and is usually less after oral administration or parenteral injection (such as under the skin or in muscle). In the latter cases, losses occur in the gut and at the injection sites. The definition also shows that for a constant dose D, the area under the curve varies inversely with the rate of elimination kp and with the volume of distribution V. Figure 39.6 illustrates schematically the different cases that can be obtained by varying the volume of distribution Vp and the rate of elimination k both on linear and semilogarithmic diagrams. These diagrams show that the slope (time course) of the curves are governed by the rate of elimination and that elevation (amplitude) of the curve is determined by the volume of distribution. 

Selecting the Right Number of Cycles in the Semilogarithmic Diagram... 

Figure 8.3 shows the disappearance of dieldrin from blood during the first 20 days after administration. When plotted in a semilogarithmic diagram, the two branches of the curve are seen and may be resolved into two straight lines. Dieldrin that has been taken up through the food disappears, for instance, via urinary excretion and via metabolism in the liver. 

In qualitative terms, microscopic interactions are caused by differences in crystal chemical properties of trace element and carrier, such as ionic radius, formal charge, or polarizability. This type of reasoning led Onuma et al. (1968) to construct semilogarithmic plots of conventional mass distribution coefficients K of various trace elements in mineral/melt pairs against the ionic radius of the trace element in the appropriate coordination state with the ligands. An example of such diagrams is shown in figure 10.6. 

This can be elucidated by a corrosion diagram (Fig. 12), which shows in semilogarithmic coordinates current-voltage characteristics for two conjugated reactions. Using condition (43) and neglecting ohmic potential drop in the system, one can find from the intersection of those characteristics the steady state corrosion current icorr and corrosion potential [Pg.283]

The series of synthetically generated mixtures of two water types given in Table 6.4 is drawn in Fig. 6.3 in a fingerprint diagram on semilogarithmic... 

The Evans diagram ( ) is a graphical presentation in semilogarithmic coordinates of the anodic and cathodic reaction rates expressed as partial currents dependent on potential. The basis for the Evans diagram is the corrosion model discussed above ... 

These equations are straight lines in a plot of E versus log i, such as that in Fig. 2. This plot of versus log i is called an Evans diagram. Actually, the Butler-Volmer equation is described better by the curve in Fig. 5. The net current at the reversible potential is zero because the forward and reverse current, each equal to the exchange current density, balance each other. The log of the current density approaches negative infinity at the reversible potential at which the net current density goes to zero, and the polarization curve points down at the reversible potential when plotted on semilogarithmic axes. 

In practice, the metal takes up an intermediate value during corrosion, the corrosion potential Ecorr (Fig- corr is the corrosion current. corr icoRR appear at the point of intersection of linear polarization curves for metal dissolution and hydrogen evolution on a semilogarithmic plot (Fig. 10.8). In order to make the diagram applicable to localized attack (when the anode and cathode sizes are disparate) it is necessary to strictly plot log current rather than log current density. 

Semilogarithmic plots of the partial anodic and cathodic current densities of mixed electrodes as shown in Figure 3 are called Evans diagrams. The determination of the... 

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