Niobium is a chemical element with symbol Nb and atomic number 41. A rare, soft, grey, ductile transition metal, niobium is found in the minerals pyrochlore (the main source for niobium) and columbite. Niobium has similar physical and chemical properties to another element, tantalum, and the two are therefore difficult to distinguish. The German chemist Heinrich Rose determined in 1846 that tantalum ores contain a second element, which he named niobium, after Niobe from Greek mythology. It was not until the early 20th century that niobium was first used commercially. Brazil is the leading producer of niobium and ferroniobium, an alloy of niobium and iron. Niobium is used mostly in alloys, the largest part in special steel such as that used in gas pipelines. Although alloys contain only a maximum of 0.1%, that small percentage improves the strength of the steel. The temperature stability of niobium-containing superalloys is important for its use in jet engines and rocket engines. Niobium is used in various superconducting materials. These superconducting alloys, also containing titanium and tin, are widely used in MRI scanners. Other applications of niobium include its use in welding, nuclear industries, electronics, optics, numismatics and jewellery. In the last two applications, niobium's low toxicity and ability to be coloured by anodisation are particular advantages.
Read the rest of this article: <http://en.wikipedia.org/wiki/Niobium> _______________________________ Today's selected anniversaries: 1853: The first passenger line of what would become Indian Railways, the state-owned railway company of India, opened between Bombay and Thane. <http://en.wikipedia.org/wiki/Indian_Railways> 1912: American Harriet Quimby became the first woman to fly across the English Channel. <http://en.wikipedia.org/wiki/Harriet_Quimby> 1947: American financier and presidential adviser Bernard Baruch first described the post-World War II tensions between the Soviet Union and the United States as a "cold war". <http://en.wikipedia.org/wiki/cold_war> 2003: The Treaty of Accession was signed in Athens, admitting ten new member states, including several countries of the former Eastern Bloc, into the European Union. <http://en.wikipedia.org/wiki/Treaty_of_Accession_2003> 2007: In one of the deadliest shooting incidents in United States history, a gunman killed 32 people and wounded over 20 more before committing suicide at Virginia Tech University in Blacksburg, Virginia. <http://en.wikipedia.org/wiki/Virginia_Tech_massacre> _____________________________ Wiktionary's word of the day: prosaic (adj): 1. Pertaining to or having the characteristics of prose. 2. (of writing or speaking) Straightforward; matter-of-fact; lacking the feeling or elegance of poetry. 3. (figurative) Overly plain or simple, to the point of being boring; humdrum <http://en.wiktionary.org/wiki/prosaic> ___________________________ Wikiquote quote of the day: All changes, even the most longed for, have their melancholy; for what we leave behind us is a part of ourselves; we must die to one life before we can enter another. --Anatole France <http://en.wikiquote.org/wiki/Anatole_France> _______________________________________________ Wikipedia Daily Article mailing list. To unsubscribe, visit: https://lists.wikimedia.org/mailman/listinfo/daily-article-l Questions or comments? Contact [email protected]
