Polonium were marketed by Firestone from 1940 to 1953. While the amount of radiation from the plugs was minuscule and not a threat to the consumer, the benefits of such plugs quickly diminished after approximately a month because of polonium's short half-life and because buildup on the conductors would block the radiation that improved engine performance. (The premise behind the polonium spark plug, as well as Alfred Matthew Hubbard's prototype radium plug that preceded it, was that the radiation would improve ionization of the fuel in the cylinder and thus allow the motor to fire more quickly and efficiently.) Polonium is
Discover Financial the Diners Club International network from Citigroup for $165 million. In May 2008, the Federal Trade Commission approved the transaction and it finalized on July 1, 2008. Discover stated that the Diners Club network, which is a major network outside the United States, will be merged with the Discover Network, a major network in the United States, creating an international network for Discover and Diners Club cardholders. Diners Club cards will continue to be issued by Diners Club International licensees. At this time, Discover Bank has no plans on issuing Diners Club branded cards itself. On September 17, 2010, Discover