Electron Beam Welding (EBW) is a fusion joining process that produces a weld by impinging a beam of high-energy electrons to heat the weld joint. Electrons are elementary atomic particles characterized by a negative charge and an extremely small mass. Raising electrons to a high-energy state by accelerating them to roughly 30 to 70 percent of the speed of light provides the energy to heat the weld. The electron beam is always generated in a high vacuum. The use of specially designed orifices separating a series of chambers at various levels of vacuum permits welding in medium and non-vacuum conditions.
Electronic air cleaners remove particles by electrostatic forces similar to electrostatic precipitators used in industrial gas cleaning. There are three basic designs: the ionizing plate type, the charged-media non-ionizing type, and the charged-media ionizing type. Operation of electronic air cleaners is based on the principle that particles moving in air stream can be charged and then subsequently collected on plates of opposite charge. An electronic air cleaner draws particle-laden air past a serious of ionizing wires that produce positive ions; this air then passes through channels between a serious of negatively charged collection plates, which attract the positively charged particles. These air cleaners are more efficient than a conventional mechanical filter. They are able to capture small particulate, including pollen and cigarette smoke particles.