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Bipyramid

An n-gonal bipyramid or dipyramid is a polyhedron formed by joining an n-gonal pyramid and its mirror image base-to-base. An n-gonal bipyramid has 2n triangle faces, 3n edges, 2 + n vertices; the referenced n-gon in the name of the bipyramids is not an external face but an internal one, existing on the primary symmetry plane which connects the two pyramid halves. A right bipyramid has two points below the centroid of its base. Nonright bipyramids are called oblique bipyramids. A regular bipyramid has a regular polygon internal face and is implied to be a right bipyramid. A right bipyramid can be represented as + P for internal polygon P, a regular n-bipyramid +. A concave bipyramid has a concave interior polygon; the face-transitive regular bipyramids are the dual polyhedra of the uniform prisms and will have isosceles triangle faces. A bipyramid can be projected on a sphere or globe as n spaced lines of longitude going from pole to pole, bisected by a line around the equator. Bipyramid faces, projected as spherical triangles, represent the fundamental domains in the dihedral symmetry Dnh.

Indeed, an n-tonal bipyramid can be seen as the Kleetope of the respective n-gonal dihedron. The volume of a bipyramid is V =2/3Bh where B is the area of the base and h the height from the base to the apex; this works for any location of the apex, provided that h is measured as the perpendicular distance from the plane which contains the base. The volume of a bipyramid whose base is a regular n-sided polygon with side length s and whose height is h is therefore: V = n 6 h s 2 cot ⁡ π n. Only three kinds of bipyramids can have all edges of the same length: the triangular and pentagonal bipyramids; the tetragonal bipyramid with identical edges, or regular octahedron, counts among the Platonic solids, while the triangular and pentagonal bipyramids with identical edges count among the Johnson solids. If the base is regular and the line through the apexes intersects the base at its center, the symmetry group of the n-gonal bipyramid has dihedral symmetry Dnh of order 4n, except in the case of a regular octahedron, which has the larger octahedral symmetry group Oh of order 48, which has three versions of D4h as subgroups.

The rotation group is Dn of order 2n, except in the case of a regular octahedron, which has the larger symmetry group O of order 24, which has three versions of D4 as subgroups. The digonal faces of a spherical 2n-bipyramid represents the fundamental domains of dihedral symmetry in three dimensions: Dnh, order 4n; the reflection domains can be shown as alternately colored triangles as mirror images. An asymmetric right bipyramid joins two unequal height pyramids. An inverted form can have both pyramids on the same side. A regular n-gonal asymmetry right pyramid has order 2n; the dual polyhedron of an asymmetric bipyramid is a frustum. A scalenohedron is topologically identical to a 2n-bipyramid, but contains congruent scalene triangles. There are two types. In one type the 2n vertices around the center alternate in rings below the center. In the other type, the 2n vertices are on the same plane, but alternate in two radii; the first has 2-fold rotation axes mid-edge around the sides, reflection planes through the vertices, n-fold rotation symmetry on its axis, representing symmetry Dnd, order 2n.

In crystallography, 8-sided and 12-sided scalenohedra exist. All of these forms are isohedra; the second has order 2n. The smallest scalenohedron is topologically identical to the regular octahedron; the second type is a rhombic bipyramid. The first type has 6 vertices can be represented as, where z is a parameter between 0 and 1, creating a regular octahedron at z = 0, becoming a disphenoid with merged coplanar faces at z = 1. For z > 1, it becomes concave. Self-intersecting bipyramids exist with a star polygon central figure, defined by triangular faces connecting each polygon edge to these two points. A bipyramid has Coxeter diagram. Isohedral even-sided stars can be made with zig-zag offplane vertices, in-out isotoxal forms, or both, like this form: The dual of the rectification of each convex regular 4-polytopes is a cell-transitive 4-polytope with bipyramidal cells. In the following, the apex vertex of the bipyramid is A and an equator vertex is E; the distance between adjacent vertices on the equator EE = 1, the apex to equator edge is AE and the distance between the apices is AA.

The bipyramid 4-polytope will have VA vertices. It will have VE vertices. NAE bipyramids meet along each type AE edge. NEE bipyramids meet along each type EE edge. CAE is the cosine of the dihedral angle along an AE edge. CEE is the cosine of the dihedral angle along an EE edge; as cells must fit around an edge, NAA cos−1 ≤ 2π, NAE cos−1 ≤ 2π. * The rectified 16-cell is the regular 24-cell and vertices are all equivalent – octahedra are regular bipyramids. ** Given numerically due to more complex form. In general, a bipyramid can be seen as an n-polytope constructed with a -polytope in a hyperplane with two points in opposite directions, equal distance perpendicular from the hyperplane. If the -polytope is a regular polytope, it will have identical pyramids facets. An example is the 16-cell, an octahedral bipyramid, more an n-orthoplex is an -orth

May Bumps 1999

The May Bumps 1999 were a set of rowing races held at Cambridge University from Wednesday 9 until Saturday 12 June 1999. The event was run as a bumps race and is one of a series of May Bumps that have been held annually in mid-June since 1887. See May Bumps for the format of the races. In 1999, a total of 172 crews took part, with around 1550 participants in total. Caius men rowed-over in 1st position, retaining the headship. Emmanuel women bumped Pembroke to take their 3rd Mays headship; the highest men's 2nd VIII at the end of the week was 1st & 3rd Trinity II, who bumped Lady Margaret II on the 1st day and moved up into the 1st division. The highest women's 2nd VIII was Emmanuel II. Below are the bumps charts for all divisions; the men's bumps charts are on the left, women's bumps charts on the right. The bumps chart represents the progress of every crew over all four days of the racing. To follow the progress of any particular crew find the crew's name on the left side of the chart and follow the line to the end-of-the-week finishing position on the right of the chart.

Note: Caius V only raced for the last two days Durack, John. The Bumps: An Account of the Cambridge University Bumping Races 1827-1999 ISBN 0-9538475-1-9

Santiago Lamanna

Santiago Lamanna Misak is a Uruguayan footballer playing as a striker for El Tanque Sisley in the Uruguayan Primera División. He can play in other positions such as winger or as a second striker. Lamanna came from the youth divisions of Montevideo Wanderers, made his professional debut with Wanderers in the 1–1 draw against Liverpool on 11 April 2010. Lamanna was the team's captain at the 2012 Torneo di Viareggio in which they were eliminated in Group Stage. After competing three seasons with the club and with limited opportunities in the first team, in mid 2012 he was sent on loan to Uruguayan Primera División side El Tanque Sisley. On 23 February 2013, Lamanna scored his first goal for the club against Central Español, in match in which El Tanque Sisley won 3–1. In June 2013, he renewed his loan contract with El Tanque Sisley guaranteeing one more year with the club, he played two international matches in the 2013 Copa Sudamericana, tournament in which the club was eliminated in first stage at hands of Chilean side Colo-Colo.

During the start of the 2013–14 season Lamanna scored the first goal in the 2-1 away win against Fénix. Santiago Lamanna at Soccerway

Gary Rowe

Gary James Rowe is an Australian politician. He was the Liberal member for Cranbourne in the Victorian Legislative Assembly from 1992 to 2002, in 2012, he was elected as a councillor for Mayfield Ward in the City of Casey. Councillor Rowe was not re-elected to Casey City Council in October 2016, but was subsequently re-elected at a countback for Mayfield Ward in April 2017 after embattled Councillor Steve Beardon resigned just four months after being elected. Rowe was born in Victoria, to Douglas James and Norma Lilian Rowe, he attended Glen Waverley High School before studying at Victoria Police Academy, where he was one of the top ten graduates. In 1970 he became a police officer, but in 1974 became a consultant with National Mutual and in 1977 founded a finance and insurance company, of which he became director, he was director of a number of other finance and insurance businesses. In 1989, he was elected to Cranbourne Shire Council, serving until 1992. In 1992, Rowe was elected to the new seat of Cranbourne in the Victorian Legislative Assembly.

Following the Kennett Government's defeat in 1999 he became Parliamentary Secretary to the Leader of the Opposition. He was defeated in 2002 by Labor candidate Jude Perera

Resident Governor of the Tower of London and Keeper of the Jewel House

The Resident Governor of the Tower of London and Keeper of the Jewel House is responsible for the day-to-day running of the Tower of London. The Constable of the Tower is the most senior appointment at the Tower of London. Under the Queen's Regulations for the Army, the office of constable is conferred on a field marshal or retired general officer for a five-year term. At the conclusion of the Constable's installation ceremony, the Lord Chamberlain symbolically hands the palace over to the Constable, he in turn entrusts it to the Resident Governor. The offices of Resident Governor of the Tower of London and Keeper of the Jewel House were amalgamated in 1967. List of combined office holders: 1967: Colonel Sir Thomas Pierce Butler 1971: Major-General Sir Digby Raeburn 1979: Major-General Giles Mills 1984: Major-General Andrew Patrick Withy MacLellan 1989: Major-General Christopher Tyler 1994: Major-General Geoffrey Field 2006: Major-General Keith Cima 2011: Colonel Richard Harrold Jewel House

Kavanaugh Field

Kavanaugh Field was a minor league baseball park in Little Rock, Arkansas. It was the home of the Little Rock Travelers prior to their move to Travelers Field in 1932; the ballpark opened as West End Park. In 1915 it was renamed for former team owner and Southern Association president William M. Kavanaugh, after he had died from a sudden illness in February 1915. West End Park was the spring training site for the Boston Red Sox in 1907 and 1908; as part of vacating the ballpark after 1931, the property was sold to nearby Little Rock Central High School. The field was renamed Quigley Stadium; the field is west of the school's baseball field. The other boundaries are West 16th Street and Jones Street. Kavanaugh Field at the Arkansas Baseball Encyclopedia Travelers history at The Encyclopedia of Arkansas History & Culture West End Park / Kavanaugh Field on Flickr