Tin pest related problems such as tin whiskers. At 13.2 °C (about 56 °F) and below, pure tin transforms from the silvery, ductile metallic allotrope of β-form "white tin" to the brittle, nonmetallic, α-form "grey tin" with a diamond cubic structure. The transformation is slow to initiate due to a high activation energy but the presence of germanium (or crystal structures of similar form and size) or very low temperatures of roughly −30 °C aids the initiation. There is also a large volume increase of about 27% associated with the phase change to the nonmetallic low temperature allotrope. This frequently makes tin
Arena Naucalpan 15th Anniversary Show Arena Naucalpan 15th Anniversary Show The Arena Naucalpan 15th Anniversary Show was a major annual professional wrestling event produced and scripted by "Promociones Moreno" in conjunction with the professional wrestling promotion Consejo Mundial de Lucha Libre (CMLL), which took place on December 16, 1992 in Arena Naucalpan, Naucalpan, State of Mexico, Mexico. As the name implies the show celebrated the 15th Anniversary of the construction of Arena Naucalpan, "Promociones Morenos" main venue, in 1977. In 1996 "Promociones Moreno" became International Wrestling Revolution Group (IWRG), maintaining the annual Arena Naucalpan Anniversary tradition. The show became IWRG's longest running show and is