grinding oil
81energy conversion — ▪ technology Introduction the transformation of energy from forms provided by nature to forms that can be used by humans. Over the centuries a wide array of devices and systems has been developed for this purpose. Some of these energy …
82technology, history of — Introduction the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek technē, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both… …
83coal utilization — Introduction combustion of coal or its conversion into useful solid, gaseous, and liquid products. By far the most important use of coal is in combustion, mainly to provide heat to the boilers of electric power plants. Metallurgical coke… …
84Lead came and copper foil glasswork — This article is on the techniques of lead came and copper foil glasswork. For a general overview of stained glass art, see stained glass. A typical copper foil Tiffany lamp, with a jonquil daffodil design Lead came and copper foil glasswork are… …
85Drill bit — For the fictional character, see Drill Bit (Transformers). For the cancelled skyscraper nicknamed Drill bit, see Chicago Spire. For the types used in drilling wells, see Well drilling. From top to bottom: Spade, lip and spur (brad point), masonry …
86agriculture, origins of — Introduction the active production of useful plants or animals in ecosystems that have been created by people. Agriculture has often been conceptualized narrowly, in terms of specific combinations of activities and organisms wet rice production… …
87Froth flotation — Diagram of a cylindrical froth flotation cell with camera and light used in image analysis of the froth surface. Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. This is used in several processing… …
88Sleeve valve — The sleeve valve is a type of valve mechanism for piston engines, distinct from the more common poppet valve. They saw use in some pre World War II luxury cars, sports cars, the Willys Knight car and light truck, and saw substantial use in… …
89Cylindrical grinder — The cylindrical grinder is a type of grinding machine used to shape the outside of an object. The cylindrical grinder can work on a variety of shapes, however the object must have a central axis of rotation. This includes but is not limited to… …
90hand tool — any tool or implement designed for manual operation. * * * Introduction any of the implements used by craftsmen in manual operations, such as chopping, chiseling, sawing, filing, or forging. Complementary tools, often needed as auxiliaries to… …
