Polonium initiator was classified until the 1960s. The Atomic Energy Commission and the Manhattan Project funded human experiments using polonium on five people at the University of Rochester between 1943 and 1947. The people were administered between of polonium to study its excretion. Polonium is a very rare element in nature because of the short half-life of all its isotopes. Po, Po, and Po appear in the decay chain of U; thus polonium can be found in uranium ores at about 0.1 mg per metric ton (1 part in 10), which is approximately 0.2% of the abundance of radium. The amounts
Discover Card Discover Card Discover is a credit card brand issued primarily in the United States. It was introduced by Sears in 1985. When launched, Discover did not charge an annual fee and offered a higher-than-normal credit limit, features that were disruptive to the existing credit card industry. A subsequent innovation was "Cashback Bonus" on purchases. Most cards with the Discover brand are issued by Discover Bank, formerly the Greenwood Trust Company. Discover transactions are processed through the Discover Network payment network. In 2005, Discover Financial Services acquired Pulse, an electronic funds transfer network, allowing it to market and issue debit and