In early tests with the ligand 2-(2-Thiazolylazo)-p-cresol (TAC), we found that interference of the Fe(TAC) 1 complex may have competed with Fe(TAC) 2 for Fe. Also, i pmax was not reached in UV treated seawater after overnight equilibration ([TAC] = 40 Î¼ m, Î± Fe 3 + (TAC) 2 = 3.6 Ã 10 13).
BASE UNIT - kilogram (kg) - MASS. The standard for the kilogram is a cylinder of platinum-iridium alloy kept by the International Bureau of Weights and Measures in Paris. A duplicate at the National Bureau of Standards serves as the mass standard for the United States.
In the early metric system there were two base units, the metre for length and the gram for mass. The other units of length and mass, and all units of area, volume, and derived units such as density were derived from these two base units.