Alpha helix — A common motif in the secondary structure of proteins, the alpha helix (α helix) is a right handed coiled conformation, resembling a spring, in which every backbone N H group donates a hydrogen bond to the backbone C=O group of the amino acid… … Wikipedia
List of gear nomenclature — Gears have a wide range of unique terminology known as gear nomenclature. Many of the terms defined cite the same reference work.[1] Contents 1 Addendum 2 Addendum angle 3 Addendum circle … Wikipedia
Propeller — A propeller is essentially a type of fan which transmits power by converting rotational motion into thrust for propulsion of a vehicle such as an aircraft, ship, or submarine through a mass such as water or air, by rotating two or more twisted… … Wikipedia
Gear — For the gear like device used to drive a roller chain, see Sprocket. This article is about mechanical gears. For other uses, see Gear (disambiguation). Two meshing gears transmitting rotational motion. Note that the smaller gear is rotating… … Wikipedia
Milling cutter — Milling cutters are cutting tools typically used in milling machines or machining centres (and occasionally in other machine tools). They remove material by their movement within the machine (e.g., a ball nose mill) or directly from the cutter s… … Wikipedia
Drill 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 … Wikipedia
drill — drill1 drillable, adj. drillability, n. driller, n. /dril/, n. 1. Mach., Building Trades. a. a shaftlike tool with two or more cutting edges for making holes in firm materials, esp. by rotation. b. a tool, esp. a hand tool, for holding and… … Universalium
Endmill — An endmill is a type of milling cutter, a cutting tool used in industrial milling applications. It is distinguished from the drill bit, in its application, geometry, and manufacture. Whereas a drill bit can only cut in the axial direction, a… … Wikipedia
Otoplasty — Otoplasty: the pre operative front aspect (left), and the post operative front aspect (right) of an infantile otopexy (ear pinback) correction to a girl. Otoplasty (Greek ōtoûs, ear + plassein, to shape) denotes the surgical and non surgical… … Wikipedia
Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… … Universalium