Crossplots

Regardless of the exact extent (shorter or longer range) of the interaction of each alkali adatom on a metal surface, there is one important feature of Fig 2.6 which has not attracted attention in the past. This feature is depicted in Fig. 2.6c, obtained by crossploting the data in ref. 26 which shows that the activation energy of desorption, Ed, of the alkali atoms decreases linearly with decreasing work function . For non-activated adsorption this implies a linear decrease in the heat of chemisorption of the alkali atoms AHad (=Ed) with decreasing > ... 

The technique of AC Impedance Spectroscopy is one of the most commonly used techniques in electrochemistry, both aqueous and solid.49 A small amplitude AC voltage of frequency f is applied between the working and reference electrode, superimposed to the catalyst potential Uwr, and both the real (ZRe) and imaginary (Zim) part of the impedance Z (=dUwR/dI=ZRc+iZim)9 10 are obtained as a function of f (Bode plot, Fig. 5.29a). Upon crossplotting Z m vs ZRe, a Nyquist plot is obtained (Fig. 5.29b). One can also obtain Nyquist plots for various imposed Uwr values as shown in subsequent figures. 

These results are direct measurements of the CO concentrations which are present at the inlet to a three-way converter under realistic operating conditions. The concentrations of other exhaust components at the converter inlet can be estimated using concentration crossplots, for each component versus CO, obtained from time-averaged measurements at constant air-fuel ratio settings. 

Fig. 2. Elevation (A) and chemical (B-H) crossplots against soil sample site number. Transect is south (left) to north (right). The different B horizon soil depths are given by different line characteristics solid line = uppermost 15 om of the B horizon dashed-dotted line = 15-30 cm of the B horizon dashed line = 30-45 om of the B horizon. The XY orebody s surface projection is at the black bar. Gray lines in the background are to aid site projection across orossplots. The depositional characteristics of each soil site are T - till W - seasonally waterlogged till F - fluvioglacial till A - alluvium C - colluvium.

Fig. 2a and b - Three of 4 traditional composition measures (USDA) crossplotted (above) Idealized, contrasting clusters versus orthogonal compositions (below)... 

In fact, as can be seen in Figure 11, upon crossplotting Ed versus the work function change. A , induced by the alkali ad-atoms, a straight line with a positive slope is obtained. For nonactivated adsorption, as is the case here, this implies a... 

Fig. 5-23. Compositional crossplots of Rice s reservoir gas analysis. The underlying color code was chosen to distinguish oil, oil-condensate, gas condensate and gas within Rice s Gulf of Mexico production data.

Fig., >-24. Crossplots of the compositions of gases from offshore Louisiana (a) well gases throughout the area (b) marine sniffer gases throughout the area (c) marine sniffer gases from a gas area (d) marine sniffer gases from an oil area.

Anomaly compositions are plotted on a marine crossplot in Fig. 5-33b for comparison with the calibration crossplots in Fig. 5-24. Three regional profiles are presented in Fig. 5-34 to show the magnitude variations along the survey lines. 

Fig. 5-33. High Island geochemical sniffer survey 1988 a) sniffer track map b) marine compositional crossplot.

Fig. 5-34. Profile of dissolved hydrocarbon data from High Island sniffer survey a) east-west line A-B b) south-north line C-D c) north-south-north line E-F d) marine compositional crossplot for 1988 sniffer anomalies.

Figure 7-13. Crossplot of broadline H and CP-MAS (narrow line) l3C spectra for a 43% mixture of erucamide with i-PP. Erucamide is a fatty acid amide used with PP film to reduce adhesion of adjacent layers of film. The contours indicated by arrows are due to polypropylene -CH3, >CH- and -CH2- groups, respectively. This shows that the >CH- group at 26 ppm on the 13C resonance axis has the lowest mobility, as its proton resonance is the broadest. [Adapted from I. Quijada-Garrido, M. Wilhelm, H. W. Spiess, J. M. Barrales-Rienda, Macromol. Chem. Phys. 199, 985 (1998). Copyright 1998, Wiley Periodicals, Inc., A Wiley Company.]...

Figure 7 shows a crossplot of an aromatic sterane cracking parameter (A3) and a hopane biomarker maturity parameter (H14). The A3... 

Fig. 6. Carbon isotope crossplot for J Block and Central Graben petroleums.

Figure 15. Crossplot.5 of elemental and isotopic data from Middendorf Lake symbols are the same as those m Figure 14 (data replotted from Wolfe et al, 1999). Note that the regression line (A) for the forest period indicates the presence of inorganically bound N in these sediments, whereas that for the tundra period passes through the origin. The N intercept for the forest data has been used to correct the C/N values plotted in (C) and (D).

Crossplots are then made of log c vs log for a range of values Vo. The points are taken firom the intersections of the vertical dotted lines with the corrected concentration plots illustrated in Figure 7.2 and the cros lot is shown in Figure 7.3. From this plot for a chosen value of c, the desired clarity, a range of values of Vo and ta can be obtained. Any of these combinations will give the required clarity in the effluent and suitable ones can be picked off another crossplot of log Vo vs log ta (Figure 7.4). 

For this enq)irical method to be successful it is necessary that the slopes of the plots of log c vs log Vo have the same value, as shown in Figure 7.2, and the lines may have to be extrapolated to give the points required for the crossplots. Carefiil e q)erimentation and interpretation of the raw data are vital. 

Figure 7.3 Crossplot giving o vs t for values of. Values for overflow rate F m/h are as follows squares, 0.25 triangles, 0.5 circles, 1 crosses, 2...

Since the Mullins effect appeared to be special to elastomers, it was of interest to us, to observe how its appearance relates to more usual manifestations of inelasticity such as Data for M and are crossplotted in Fig. 4.14, therefore, for all the materials tested cyclically to an extension of 3 [175],... 

In this paper the discussion focuses largely upon systems where the gas velocity and circulation rate are die independent variables. The results may be applied to Fixed Inventory systems by crossplots of the variables. 

Figure 22. Stress plots for 10 x 3 specimens in compression at increasing tvists. Series B, increasing X at fixed 0 series C, crossplot from data taken at increasing 6 but fixed X.

Fig. 14. Crossplot of 7 / and 7 transitions obtained via photo DSC, plotted along the vertical axis, and the corresponding transitions obtained via conventional DSC and hot stage microscopy, plotted along the horizontal axis. The 45 line indicates perfect correlation.

A critical analysis of the appUcafitni of Th-K crossplots for identification of clay mineralogy for sandstones was pubUshed by Hurst (1990). The main reasons for uncertainties in clay mineralogy are ... 

Particularly of interest is the difference for the main reservoir rock-forming minerals quartz ( PE =1.81 bams/electron U=4.8 bams/cm ), caldte (PE=5.08 bams/electron U=13.8 bams/cm ) and dolomite (PE=3.14 bams/electron U = 9.0 bams/cm ). This gives a possibility of a mineral composition estimate and is implemented in crossplot techniques (see Section 5.6). 

FIGURE 5.11 Th/K versus PE crossplot for clay mineral typing. Baker Atlas (1992). 

Thus, for a porosity calculation from a density measurement, the knowledge of solid matrix material density Psoud (also called matrix density Pma) and fluid density Pfiuid is necessary. An information about matrix mineralogy can be received from geological input, crossplot techniques (see Section 5.6) and PE measurement. 

Neutron porosity is an important component for crossplot techniques and combined mineralogy-porosity calculation in order to give an estimate for matrix composition and porosity (see Section 5.6). 

Two techniques—graphic, using crossplots, and numeric, using a mathematical formalism—are presented in order to solve such problems and deliver information about both porosity and mineral composition. 

Crossplots are two-dimensional graphic presentations of the response equations. Crossplots present the variation of any two porosity-sensitive properties (for example density and neutron, but also slowness/see next chapter). All combinations are possible ... 

---