Pewter (such as cups, plates, or jewelry) due to health concerns stemming from the lead content. Modern pewters are available that are completely free of lead, although many pewters containing lead are still being produced for other purposes. A typical European casting alloy contains 94% tin, 1% copper, and 5% antimony. A European pewter sheet would contain 92% tin, 2% copper, and 6% antimony. Asian pewter, produced mostly in Malaysia, Singapore, and Thailand, contains a higher percentage of tin, usually 97.5% tin, 1% copper, and 1.5% antimony. This makes the alloy slightly softer. So-called "Mexican pewter" is an alloy of aluminum,
Blade element momentum theory We can derive an expression for formula_52 in a similar manner. This allows us to understand what is going on with the rotor and the fluid. Equations of this sort are then solved by iterative techniques. Blade element momentum theory Blade element momentum theory is a theory that combines both blade element theory and momentum theory. It is used to calculate the local forces on a propeller or wind-turbine blade. Blade element theory is combined with momentum theory to alleviate some of the difficulties in calculating the induced velocities at the rotor. This article emphasizes application of BEM to ground-based