Centripetal forces acting on a ski–skier system allow turning motions while alpine skiing, i.e. when the skier places the skis’ longitudinal axes at an angle inclined away from the velocity vector and simultaneously edges the skis into the snow, oblique cutting forces are generated in icy, hard snow. In this paper, we determine such ice cutting forces experimentally, and after deriving empirical equations for representing them, numerically simulate the tracks of turning alpine skis.

No abstract

The catalytic activity of Pt/AlPO4 for C2H4-NO-O2 in the presence of SO2 was found to be higher in terms of the maximum NO conversion and the corresponding temperature than that of Pt/Al2O3. The selectivity toward N2O (byproduct) of Pt/AlPO4 was depressed by the presence of SO2 to its advantage; while the selectivity of Pt/Al2O3 was almost unaffected. The XPS spectra of Al, P and 0 of Pt/AlPO4 were hardly affected even by the presence of SO2. On the other hand, the XPS spectra of Al and 0 of Pt/Al2O3 were evidently affected by the presence of SO2, suggesting that SO2 interacted strongly with the Al2O3 to form aluminum sulfate-like species. The high SO2-tolerance of Pt/AlPO4 could be ascribed to the low reactivity of AlPO4 with SO2.

No abstract