DC machines can be classified as self-excited, separately excited, permanent magnet (PM), and brushless. Self-excited machines can be further classified as shunt, series, and compound. Compound ...

A high-viscosity, rigid compound, Tra-Bond 216R01 has a lap shear of 3,600 psi with a room-temperature cure and 4,500 psi with a 65°C heat cure. A high-viscosity, rigid compound, Tra-Bond 216R01 has a ...

Craftsmen in ancient China were using complex machines to work jewellery long before such devices are traditionally thought to have been invented. Dr Peter Lu claims spiral grooves on 2,550-year-old ...

Distinctive spiral patterns carved into a small jade ring show that China was using complex machines more than 2500 years ago, says a Harvard graduate student in physics. The ring was among the goods ...