Oxide data

Table 7.16 Oxidation data for nickel-chromium alloys"...

Table 7.18 Oxidation data for nickel-base high-temperature alloys-...

Table 7.19 Oxidation data for commercial nickel-chromium-base alloys...

The first three form amphoteric oxides and are distinctly superior, as cement-formers, to the latter two which form weakly basic oxides. Data from Table 2.3b indicate that optimum cement formation occurs with cations that have / values lying between 18 and 29. 

In the laboratory of Professor R.G. Moore at the University of Calgary, kinetic data were obtained using bitumen samples of the North Bodo and Athabasca oil sands of northern Alberta. Low temperature oxidation data were taken at 50, 75, 100, 125 and 150"C whereas the high temperature thermal cracking data at 360, 397 and 420"C. 

Incidentally, oxidation data of the pyrrole monomers show an interesting increase in oxidation potentials when containing heavier substituents (Table 25). However, the ionization potential of N -methylpyrrole (7.95 V) is smaller than that of pyrrole (8.21 V). The accepted linear relationship between ionization potential and oxidation potential210 would have it the other way round. Considering, however, that trimethylsilyl and trimethylgermyl groups are weak electron donors211, it is plausible that a nonelectronic effect is responsible for the observed trend and the potential shifts are associated with steric effects. 

In connection with practical situations where CO oxidation is important, we must also consider the perennial question of how to connect the low pressure results onto those at high pressure. Qualitatively this has been done for the CO oxidation reaction but it would still be worthwhile to attempt a numerical prediction of high pressure results based on low-pressure rate parameters. A very nice paper modeling steady-state CO oxidation data over a supported Pt catalyst at CO and O2 pressures of several torr has very recently appeared (.25). Extension of this work to other systems in warranted and, even though unresolved questions continue to exist, every indication is that the high and low pressure data can be reliably modeled with the same rate parameters if no adsorption - desorption equilibria are assumed. 

We would like to thank Dr. J. T. Kummer for providing helpful consultation throughout this work and Dr. K. M. Adams for obtaining SO2 and CjHg oxidation data. 

Actually, on oxidation of the carbohydrate with sodium periodate, three moles of periodate are consumed and one mole of formic acid is formed. These data agree with the assumption that the disaccharide contains a pyranose and a furanose ring. The possibility that the disaccharide is made up of glucofuranose and sorbopyranose can also be eliminated on the basis of the periodate oxidation data. Glucofuranose would contain two pairs of adjacent hydroxyls, on carbon atoms 2 and 3 and on 5 and 6, and the sorbopyranose would have three adjacent hydroxyls, on carbon atoms 3, 4 and 5. In oxidizing such a disaccharide, a total of four moles of periodate would thus be used, giving rise to one mole of formic acid. This is inconsistent with the experimental data. 

Summary of Nonlinear Fitting of Naphthalene Oxidation Data... 

Figure 17. Comparison of 5 Fe values for bulk igneous rocks (O), suspended river loads ( ) and individual minerals from volcanic rocks (right panel). Left panel shows the fraction of Fe that exists as oxides (data for igneous rocks arbitrarily plotted as 0.02). Right panel shows 6 Fe values for coexisting magnetite ( ), olivine (+), hornblende (O), and biotite (O) in four volcanic rocks. Data from Canfield (1997), Beard et al. (2003a), and Beard and Johnson (2004).

Simply using the electronegativities or IPs of the chalcogens would lead to the prediction that for a series of compounds, the O-containing compound would oxidize least readily and the Te-containing compound would be most easily oxidized (Table 7). In most cases, the oxidation data match this prediction. Only in a small number of cases does it not, and in those cases it can be attributed to the structural environment in which the chalcogen is found. 

It should be noted that there are still unresolved discrepancies in oxidant data owing to differences in primary standards. lodometric calibration techniques for ozone monitors were compared by an ad hoc committee appointed by the California Air Resources Board (carb). The committee set out to find an accurate method for measuring ozone, to relate the recommended method to earlier data, and to recommend... 

TABLE 4-17 Percentage of Days for Which Oxidant Data Are Available from camp Sites, May-October and June-August"... 

The chief objective of this section is to provide a perspective concerning the reliability of atmospheric-oxidant data. The expected performance of atmospheric-oxidant monitors is given in Table 6-7. To judge the reliability of measurements, information about the following five factors is required ... 

It is important to separate conceptually, and in practice, the calibration process from the monitoring process. Photochemical oxidants consisting primarily of ozone were firrt continuously measured in southern California by measuring the color change of potassium iodide solutions brought into contact with the ambient air. This measurement continues to yield valid photochemical-oxidant data in California. However, it has yielded questionable data at ambient air monitoring sites elsewhere in... 

Table 5.58 Gibbs free energy of formation from elements at r = 298.15 K and P = 1 bar for fictive structural oxide components of layered silicates (Tardy and Garrels, 1974) compared with the actual thermodynamic values of stable oxides (data in kJ/mole). ...

Tab. 6.2 Magnetic properties of the iron oxides (data from Coey, 1988, and Soffel, 1991 with permission)...

Tab. 7.5 Ultraviolet-visible absorption bands and electron transitions for the iron oxides (data for magnetite, A/ustite and akaganeite from Strens Wood, 1979 A/ith permission bernalite from McCammon et al.,1995 remainder from Sherman Waite, 1985 A/ith permission)...

Fig. 1.1.20 Differential thermal analysis data for chromium hydrous oxide, hematite, and hematite particles coated with chromium hydrous oxide. Data refer to dispersions as illustrated in Fig. 1.1.19.

Based on the N02-soot oxidation data promoted by the catalytic coating tested in Konstandopoulos et al. (2000) an R value of about 3.4 has been computed. This represents a significant enhancement. 

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