. "SDN:P07::0580KMBR" . "2018-02-12 16:53:18.0" . "accepted"@en . "radioactivity_concentration_of_240U_in_air"@en . . "SDN:P07::0580KMBR" . "2018-02-12 16:53:18.0" . . "false" . "1" . . . . "SDN:P07::0580KMBR" . "\"Radioactivity\" means the number of radioactive decays of a material per second. \"Radioactivity concentration\" means radioactivity per unit volume of the medium. \"U\" means the element \"uranium\" and \"240U\" is the isotope \"uranium-240\" with a half-life of 5.99e-01 days."@en . "" . "1" .