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 debut of Blue Demon, who would later become one of the iconic figures of Mexican wrestling. The 1948 Anniversary show commemorated the 15th anniversary of the Mexican professional wrestling company "Empresa Mexicana de Lucha Libre" (Spanish for "Mexican Wrestling Promotion"; EMLL) holding their first show on September 22, 1933 by promoter and founder Salvador Lutteroth. EMLL was rebranded early in 1992 to become "Consejo Mundial de Lucha Libre" ("World Wrestling Council"; CMLL) signal their departure from the National Wrestling Alliance. With the sales of the Jim Crockett Promotions to Ted Turner in 1988 EMLL became the oldest, still-operating wrestling promotion