hydraulic rotary drilling
51Han Dynasty — 漢朝 ← 206 BCE–220 CE …
52Countersink — A countersink is a conical hole cut into a manufactured object, or the cutter used to cut such a hole. A common usage is to allow the head of a countersunk bolt or screw, when placed in the hole, to sit flush with or below the surface of the… …
53Laser cutting — process on a sheet of steel. CAD (top) and stainless steel laser cut part (bottom) Laser cutting is a technology that uses a laser to cut materials, an …
54Dixon Valve & Coupling Company — is a manufacturer and supplier of hose fittings and accessories. The company, often referred to as just Dixon, offers products for fire protection, food processing, dairy processing, beverage and brewery operations, industrial manufacturing,… …
55Outline of machines — The following outline is provided as an overview of and topical guide to machines: Machine – any device that performs or assists in performing useful work. A machine normally requires an energy source ( input ) and accomplishes some sort of… …
56Compressed-air vehicle — The Victor Tatin airplane of 1879 used a compressed air engine for propulsion. Original craft, at Musée de l Air et de l Espace …
57Muslim Agricultural Revolution — The Islamic Golden Age from the 8th century to the 13th century witnessed a fundamental transformation in agriculture known as the Arab Agricultural Revolution, Medieval Green Revolution, [A. M. Watson (1981), A Medieval Green Revolution: New… …
58Erdgas — Kugelgasbehälter Erdgas ist ein brennbares Naturgas, das in unterirdischen Lagerstätten vorkommt. Es tritt häufig zusammen mit Erdöl auf, da es auf ähnliche Weise entsteht. Erdgase bestehen hauptsächlich aus hochentzündlichem Methan,… …
