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
ROH 15th Anniversary Show ROH 15th Anniversary Show ROH 15th Anniversary was the two-night 15th ROH Anniversary Show professional wrestling pay-per-view (PPV) event produced by the American wrestling promotion Ring of Honor. It took place on March 10 and 11, 2017, at the Sam's Town Live in the Las Vegas suburb of Sunrise Manor, Nevada. The first night was a pay-per-view broadcast, while the following night was a set of tapings for the ROH flagship program "Ring of Honor Wrestling". ROH 15th Anniversary features professional wrestling matches that involved wrestlers from pre-existing scripted feuds or storylines that play out on ROH's television program, "Ring