Rolling-element bearing

A rolling-element bearing, also known as a rolling bearing, is a bearing which carries a load by placing rolling elements (such as balls or rollers) between two bearing rings called races. The relative motion of the races causes the rolling elements to roll with very little rolling resistance and with little sliding.

One of the earliest and best-known rolling-element bearings are sets of logs laid on the ground with a large stone block on top. As the stone is pulled, the logs roll along the ground with little sliding friction. As each log comes out the back, it is moved to the front where the block then rolls on to it. It is possible to imitate such a bearing by placing several pens or pencils on a table and placing an item on top of them. See "bearings" for more on the historical development of bearings.

A rolling element rotary bearing uses a shaft in a much larger hole, and cylinders called "rollers" tightly fill the space between the shaft and hole. As the shaft turns, each roller acts as the logs in the above example. However, since the bearing is round, the rollers never fall out from under the load.

Cage (graph theory)

In the mathematical area of graph theory, a cage is a regular graph that has as few vertices as possible for its girth.

Formally, an (r,g)-graph is defined to be a graph in which each vertex has exactly r neighbors, and in which the shortest cycle has length exactly g. It is known that an (r,g)-graph exists for any combination of r ≥ 2 and g ≥ 3. An (r,g)-cage is an (r,g)-graph with the fewest possible number of vertices, among all (r,g)-graphs.

If a Moore graph exists with degree r and girth g, it must be a cage. Moreover, the bounds on the sizes of Moore graphs generalize to cages: any cage with odd girth g must have at least

vertices, and any cage with even girth g must have at least

vertices. Any (r,g)-graph with exactly this many vertices is by definition a Moore graph and therefore automatically a cage.

There may exist multiple cages for a given combination of r and g. For instance there are three nonisomorphic (3,10)-cages, each with 70 vertices : the Balaban 10-cage, the Harries graph and the Harries–Wong graph. But there is only one (3,11)-cage : the Balaban 11-cage (with 112 vertices).

The Cage (ballet)

The Cage is a ballet made by New York City Ballet ballet master Jerome Robbins to Stravinsky's Concerto in D for string orchestra, also known as the "Basel Concerto", which he was commissioned to compose on the twentieth anniversary of the chamber orchestra Basler Kammerorchester; it notably shifts between D major and minor. The premiere took place on Sunday, 10 June 1951 at the City Center of Music and Drama, New York, with décor by Jean Rosenthal, costumes by Ruth Sobatka and lighting by Jennifer Tipton. It was danced as part of City Ballet's 1982 Stravinsky Centennial Celebration.

Cast

original

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Twirl

Twirl is the act of spinning quickly and lightly, and it may also refer to:

See also

Twirl (chocolate bar)

Twirl is a brand of chocolate bar currently manufactured by Cadbury Ireland. Introduced by Cadbury Ireland as a single bar in the early 1970s, it was repackaged in 1984 as a twin bar. Although still produced in Ireland it has been marketed internationally since the 1990s and is now one of the best-selling chocolate single bar Cadbury owns. It consists of two Flake-style bars covered in milk chocolate.

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Twirl (album)

Twirl is the second studio album by the world music band Aomusic. It was released Feb 17, 2009 on Arcturian Gate. The album debuted on international music charts at #5.

Track listing

Personnel

Guest personnel

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