File:Prototype synthetic quartz autoclave 1959.jpg

Prototype_synthetic_quartz_autoclave_1959.jpg(345 × 417 pixels, file size: 51 KB, MIME type: image/jpeg)


English: R. A. Sullivan and R. A. Ladice examining synthetic quartz crystals grown in the autoclave shown in Western Electric's pilot hydrothermal quartz plant in North Andover, Massachussetts in 1959. Until WW2, quartz crystals used in electronic equipment were natural crystals, mined in Brazil. Shortages due to military demand for quartz led to postwar efforts to culture synthetic quartz crystals. AT&T's Bell Labs first developed a process that was capable of industrial production, growing quartz crystals at high pressure and temperature in the autoclave shown. By the 1970s virtually all quartz used in the electronics industry was synthetic.
Source Retrieved August 3, 2014 from Radio and Television News magazine, Ziff-Davis Publishing Co., Chicago, Vol. 61, No. 3, March 1959, p. 120 on American Radio History site
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This 1959 issue of Radio and Television News magazine would have the copyright renewed in 1987. Online page scans of the Catalog of Copyright Entries, published by the US Copyright Office can be found here. [1] Search of the Renewals for Periodicals for 1978 to present show no renewal entries for Radio and Television News. Therefore the magazine's copyright was not renewed and it is in the public domain.


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This work is in the public domain because it was published in the United States between 1924 and 1963 and although there may or may not have been a copyright notice, the copyright was not renewed. Unless its author has been dead for the required period, it is copyrighted in the countries or areas that do not apply the rule of the shorter term for US works, such as Canada (50 pma), Mainland China (50 pma, not Hong Kong or Macao), Germany (70 pma), Mexico (100 pma), Switzerland (70 pma), and other countries with individual treaties. See Commons:Hirtle chart for further explanation.

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current15:05, 4 August 2014Thumbnail for version as of 15:05, 4 August 2014345 × 417 (51 KB)ChetvornoUser created page with UploadWizard
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