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
Lead 15th Anniversary Live Box MCs. For "Lead 15th Anniversary Live ～Kan Ima Shirube-sai～", the group performed every a-side they had released since their debut in 2002, up until their then-most recent song "Beautiful Day", which had been released on August 23, 2017. The live was well-received, with people praising the group's stage presence and charisma, even with performing so many songs for one performance, many of which were dance tracks. "Lead Upturn 2017 ～This is Our Day～" was the group's fifteenth live tour. For the performance, most of the music utilized were songs from their seventh studio album "The Showcase", which had been released