Blue

Blue is the colour between violet and green on the optical spectrum of visible light. Human eyes perceive blue when observing light with a wavelength between 450 and 495 nanometres. Blues with a higher frequency and thus a shorter wavelength gradually look more violet, while those with a lower frequency and a longer wavelength gradually appear more green. Pure blue, in the middle, has a wavelength of 470 nanometres. In painting and traditional colour theory, blue is one of the three primary colours of pigments, along with red and yellow, which can be mixed to form a wide gamut of colours. Red and blue mixed together form violet, blue and yellow together form green. Blue is also a primary colour in the RGB colour model, used to create all the colours on the screen of a television or computer monitor.

The modern English word blue comes from Middle English bleu or blewe, from the Old French bleu, a word of Germanic origin, related to the Old High German word blao. The clear sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. When sunlight passes through the atmosphere, the blue wavelengths are scattered more widely by the oxygen and nitrogen molecules, and more blue comes to our eyes. Rayleigh scattering also explains blue eyes; there is no blue pigment in blue eyes. Distant objects appear more blue because of another optical effect called atmospheric perspective.

Blue (tourism magazine)

Blue was an adventure travel magazine, founded in 1997 by Amy Schrier, with David Carson as the original design consultant. Its focus was on global adventure travel. It was published in New York and is now out of print; its last issue was February–March 2000.

The cover of its first issue was included in a list of the Top 40 magazine covers of the last 40 years by the American Society of Magazine Editors. In 1999 Life magazine listed it in the Best Magazine Photos of the Year. The New York Times characterized it as "not your father's National Geographic."

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Blue Gender

Blue Gender (Japanese: ブルージェンダー, Hepburn: Burū Jendā) is a 26-episode anime created, co-directed and co-written by Ryōsuke Takahashi (of Armored Trooper Votoms and Gasaraki fame) broadcast in Japan from 1999-2000. Blue Gender was created by the Japanese animation studio, AIC and is distributed in the United States by Funimation Entertainment. In 2003, Blue Gender was released on American television as part of Cartoon Network's Adult Swim, though it had originally been planned for Toonami, and was thus edited to remove its graphic violence, nudity, and sex scenes (however, its airing on Colours TV and Funimation Channel in the United States). There is also a compilation movie (Blue Gender: The Warrior) available on DVD with an alternative ending. The series was also shown on the Sci Fi Channel in the UK in 2002-2003. The Blue Gender series is set in the 2030s, in which Earth has been overrun by the Blue, which are mutated insect-like creatures containing a newly evolved B-cell that recently appeared in several humans, including the main protagonist, Yuji Kaido, that kill and harvest humans for food. Most of the surviving human race has moved to Second Earth, a huge space station that orbits the planet. The series mostly focuses on Yuji and Marlene's relationship as they work together to reach Second Earth and their participation in military combat operations against the Blue.

Wheel

A wheel is a circular component that is intended to rotate on an axle bearing. The wheel is one of the main components of the wheel and axle which is one of the six simple machines. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel and flywheel.

Common examples are found in transport applications. A wheel greatly reduces friction by facilitating motion by rolling together with the use of axles. In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, either by way of gravity, or by the application of another external force or torque.

Etymology

The English word wheel comes from the Old English word hweol, hweogol, from Proto-Germanic *hwehwlan, *hwegwlan, from Proto-Indo-European *k^wek^wlo-, an extended form of the root *k^wel- "to revolve, move around". Cognates within Indo-European include Icelandic hjól "wheel, tyre", Greek κύκλος kúklos, and Sanskrit chakra, the latter both meaning "circle" or "wheel".

List of gear nomenclature

Addendum

The addendum is the height by which a tooth of a gear projects beyond (outside for external, or inside for internal) the standard pitch circle or pitch line; also, the radial distance between the pitch diameter and the outside diameter.

Addendum angle

Addendum angle in a bevel gear, is the angle between elements of the face cone and pitch cone.

Addendum circle

The addendum circle coincides with the tops of the teeth of a gear and is concentric with the standard (reference) pitch circle and radially distant from it by the amount of the addendum. For external gears, the addendum circle lies on the outside cylinder while on internal gears the addendum circle lies on the internal cylinder.

Pressure Angle

Apex to back

Apex to back, in a bevel gear or hypoid gear, is the distance in the direction of the axis from the apex of the pitch cone to a locating surface at the back of the blank.

Back angle

The back angle of a bevel gear is the angle between an element of the back cone and a plane of rotation, and usually is equal to the pitch angle.