Alexander Friedrich Just (12 April 1874, in Bremen – 30 May 1937, in Budapest) was an Austro-Hungarian chemist and inventor. Later, in Hungary he used the name Just Sándor Frigyes. In 1904 with Austro-Hungarian Franjo Hanaman he was the first to develop and patent an incandescent light bulb with a tungsten filament, made by extruding a paste of tungsten powder and a carbonaceous binder to produce a fine thread, then removing the carbon by heating in an atmosphere of hydrogen and water vapors. Just and Hanaman received a Hungarian patent in 1904, and later US Patent 1,018,502. In 1905, Just and Hanaman patented a process for producing tungsten filaments by plating carbon filaments with tungsten, then removing the carbon by heating.Hirst, H. "Recent progress in tungsten metallic filament lamps," The Electrical Journal, Volume LXI, May 22, 1908, pages 215-216. Retrieved December 14, 2011 These early tungsten lamps were more efficient than a carbon filament lamp, because they could operate at a high temperature, due to the high melting point of tungsten. The tungsten was, however, so brittle that these lamps were of limited practical use.Day, Lance and McNeil, Ian "Biographical dictionary of the history of technology," Routledge, 1996. Cited edition is Taylor & Francis eBook, 2005, page 290. . Retrieved December 14, 2011. It was supplanted by the drawn tungsten filament lamp, developed in 1910 by William David Coolidge.
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External links NY-Times 16 April 1916 about Just (pdf)