rotary-field motor
61petroleum production — Introduction recovery of crude oil and, often, associated natural gas from the Earth. petroleum is a naturally occurring hydrocarbon material that is believed to have formed in deep sedimentary (sedimentary rock) beds from animal and …
62Nikola Tesla — Tesla, aged 37, 1893, photo by Sar …
63Single-lens reflex camera — The single lens reflex (SLR) camera uses an automatic moving mirror system which permits the photographer to see exactly what will be captured by the film or digital imaging system, as opposed to non SLR cameras where the view through the… …
64Milling machine — For the machine used in road construction, see Asphalt milling machine. Not to be confused with mill (grinding). Example of a bridge type CNC vertical milling center …
65History of perpetual motion machines — The history of perpetual motion machines dates back to the Middle Ages. For millennia, it was not clear whether perpetual motion devices were possible or not, but the development of modern thermodynamics has indicated that they are impossible.… …
66Engine — This article is about a machine to convert energy into useful mechanical motion. For other uses of engine, see Engine (disambiguation). For other uses of motor, see Motor (disambiguation). A V6 internal combustion engine from a Mercedes car An… …
67International Harvester — For the song by Craig Morgan, see International Harvester (song). For the Swedish progg band, see Träd, Gräs Stenar. International Harvester Company Industry Agricultural, Automotive Successor Navistar International Corporation …
68Hughes Christensen — Hughes Christensen, a division of Baker Hughes Inc., is a large oil and gas drill bit company. Howard Hughes, Sr. founded the company early in the 20th century. His two cone, rolling cutter rock bit whose patent was issued by the US Patent Office …
69Physical Sciences — ▪ 2009 Introduction Scientists discovered a new family of superconducting materials and obtained unique images of individual hydrogen atoms and of a multiple exoplanet system. Europe completed the Large Hadron Collider, and China and India took… …
70clothing and footwear industry — Introduction also called apparel and allied industries, garment industries, or soft goods industries, factories and mills producing outerwear, underwear, headwear, footwear, belts, purses, luggage, gloves, scarfs, ties, and household… …
