"" . "2019-03-04 17:29:46.0" . . "accepted"@en . "SDN:P07::CF12N276" . . "mass_concentration_of_hydroxyl_radical_in_air"@en . . . "2" . . . . "2019-03-04 17:29:46.0" . "false" . "\"Mass concentration\" means mass per unit volume and is used in the construction \"mass_concentration_of_X_in_Y\", where X is a material constituent of Y. A chemical or biological species denoted by X may be described by a single term such as \"nitrogen\" or a phrase such as \"nox_expressed_as_nitrogen\". The chemical formula for the hydroxyl radical is OH. In chemistry, a \"radical\" is a highly reactive, and therefore short lived, species."@en . "SDN:P07::CF12N276" . . "2" . "SDN:P07::CF12N276" .