Cadmium in Germany, as an impurity in zinc carbonate. Stromeyer found the new element as an impurity in zinc carbonate (calamine), and, for 100 years, Germany remained the only important producer of the metal. The metal was named after the Latin word for calamine, because it was found in this zinc ore. Stromeyer noted that some impure samples of calamine changed color when heated but pure calamine did not. He was persistent in studying these results and eventually isolated cadmium metal by roasting and reducing the sulfide. The potential for cadmium yellow as pigment was recognized in the 1840s, but the
Ore extension polynomial derivative. Ore algebras are a class of iterated Ore extensions under suitable constraints that permit to develop a noncommutative extension of the theory of Gröbner bases. An element "f" of an Ore ring "R" is called 3.^ Azeddine, Ouarit. Extensions de ore d'anneaux noethériens à I. P. et identités auto-différentielles d'anneaux semi-premiers. Thèse de doctorat en Mathématiques (1991) Poitiers, France. http://www.theses.fr/1991POIT2260 Ore extension In mathematics, especially in the area of algebra known as ring theory, an Ore extension, named after Øystein Ore, is a special type of a ring extension whose properties are relatively well understood. Elements of a