Titanium temperature effect

Based on detailed kinetic investigations, a tentative mechanism for this asymmetric oxidation was proposed (Scheme 2) according to which optically active sulphoxides may be formed by two pathways external attack on the sulphur atom by the chiral titanium hydroperoxide (path A) or coordination of sulphur to titanium prior to the oxidation step (path B). Although paths A and B could not be distinguished experimentally, the temperature effect was tentatively ascribed to a change of the mechanism, path A being predominant above — 20 °C and path B becoming competitive at lower temperatures (or vice versa). 

Henry, D.J., Guidotti, C.V. (2002) Titanium in biotite from metapelitic rocks temperature effects, crystal-chemical controls, and petrologic apphcations. Am. Mineral, 87, 375-382. 

The above results show that the stability domain of the various oxidation states of titanium chlorides varies according to the solvent composition. However, this influence must be studied in connection with the concentration and temperature effect. In the presence of metallic titanium, the ratio, 7 =Ct p+/cj 2+, depends dramatically on the concentration and temperature. For a concentration of titanium ions, c, the ratio, r, is given... 

Figure 13.1 Surface metallopinacols on active titanium and uranium. Table 13.2 Temperature effect on reaction of benzophenone with U. ...

Knoop single crystal, 83 temperature effect, 78 Vickers single crystal, 93 toughness, 187 Titanium nitride (TiN), 297 hardness of thin film, 50 Titanium dioxide, TiOj, 124 Tolerance factor, 287 Topotaxy in ZrOj transformations, 272 Toughness, 145 mechanisms in Z1O2, 27 Transformation toughening, 273 Transition metal carbides, anisotropy in, 75 Transition metal nitrides, anisotropy in, 75 Trichloroborazine, 231 Tridymite, 236... 

Elastic moduli for commercial purity titanium is higher than that of high-purity (99.9%) titanium, but interstitial impurities have less influence on temperature effects (H. Conrad efaf., Titanium Science and Technology, Renum Press, 1973,p970)... 

Fig. 7. The effect of preparation on the pore size distribution (a), titanium dispersion (b), and the activity for epoxidation of cyclohexene (c) of titania—siUca containing 10 wt % titania and calcined in air at 673 K. Sample A, low-temperature aerogel Sample B, high-temperature aerogel Sample C, aerogel.

Table 3.36. Effect of Elevated Temperatures on Strength of Titanium and Alloys [35]...

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