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
EMLL 15th Anniversary Show noticed by the referee. Records indicated that there were two preliminary matches on the September 24th show, but records of neither the participants nor the actual results of these matches have been confirmed. The third match of the night featured Rito Romero wrestling against Black Shadow, but no record of who won is found. Likewise the results of the fourth match between Gory Guerrero and Bobby Bonales are also undocumented. In the main event NWA World Middleweight Champion Tarzán López successfully defended the championship against the challenger Harry Fields in a Best two-out-of three falls match. EMLL 15th Anniversary Show