Inert gas asphyxiation accidental death in humans, inert gas asphyxia with gases including helium, nitrogen, methane and argon has been used as a suicide method. Inert gas asphyxia has been advocated by proponents of euthanasia, using a gas-retaining plastic hood device colloquially referred to as a suicide bag. Nitrogen asphyxiation has been suggested by a number of lawmakers and other advocates as a more humane way to carry out capital punishment. In April 2015, the Oklahoma Governor Mary Fallin signed a bill authorizing nitrogen asphyxiation as an alternative execution method in cases where the state's preferred method of lethal injection was not available
Incandescent light bulb 1914, 88.5 million lamps were used, (only 15% with carbon filaments), and by 1945, annual sales of lamps were 795 million (more than 5 lamps per person per year). Of the power consumed by typical incandescent light bulbs, 95% or more is converted into heat rather than visible light. Other electrical light sources are more effective. Luminous "efficacy" of a light source may be defined in two ways. The radiant luminous efficacy (LER) is the ratio of the visible light flux emitted (the "luminous flux") to the total power radiated over all wavelengths. The source luminous efficacy (LES) is the