Boron, arsenic, and antimony, among other substances, are used as dopants when added to a pure semiconductor material to alter its electrical characteristics.
Artificially produced gemstones[?] (such as Ruby (gemstone)) usually contain a dopant to identify them as such.
... in a democratic society);
limits on freedom of peaceable assembly and free association are accepted in Canada as well (art. 11{2) ECHR: No restrictions shall be placed on ...