Acre

The acre is a unit of land area used in the imperial and US customary systems. It is defined as the area of 1 chain (22 yards) by 1 furlong (220 yards), which is exactly equal to ¹⁄₆₄₀ of a square mile, 43,560 square feet, approximately 4,047 m², or about 40% of a hectare.

The acre is commonly used in Antigua and BarbudaAustralia, American Samoa,The Bahamas,Belize, the British Virgin Islands, the Cayman Islands,Canada,Dominica, the Falkland Islands,Grenada,Ghana, Guam, the Northern Mariana Islands,India, Ireland, Jamaica,Montserrat,Myanmar, Pakistan, Samoa,St. Lucia,St. Helena,St. Kitts and Nevis,St. Vincent and the Grenadines,Turks and Caicos, the United Kingdom, the United States and the US Virgin Islands.

The international symbol of the acre is ac. The most commonly used acre today is the international acre. In the United States both the international acre and the slightly different US survey acre are in use. The most common use of the acre is to measure tracts of land. One international acre is defined as exactly 4,046.8564224 square metres.

Acre River

The Acre River (called Aquiry in the local Iñapari language; locally, Rio Acre) is a 680 kilometres (420 mi) long river in central South America. The river is born in Peru, and runs North-Eastwards, forming part of the border between Bolivia and Brazil. It runs through the Brazilian states of Acre and Amazonas before eventually running into the Purus River at Boca do Acre. It boards on the Bolivian frontier and flows Easter and North to a junction with the Purus at 8° 45' South latitude. The name is also applied to a district situated on the same river and on the former boundary line of 1867, between Bolivia and Brazil. This region's area is estimated at about 60,000 square miles (160,000 km²).

It is navigable from the mouth until the Xapuri River (480 kilometres (300 mi)), even farther in the wet season from January until May. The river was an important transportation artery at the end of the 19th Century due to newly discovered rubber tree forests.

History

The region was settled by Peruvians between 1870 and 1878, but was invaded by Brazilian rubber collectors during the next decade (during the 'rubber boom') and became tributary to the rubber markets of Iquitos, Manaus and Pará. In 1899, the Bolivian government established a custom-house at Puerto Alonso, on the Acre river, for the collection of export duties on rubber, which precipitated a conflict with the Brazilian settlers, and finally brought about a boundary dispute between the two republics. In July 1899 the "Acreanos" declared their independence and set up a republic of their own, but in the following March they were reduced to submission by Brazil. Various disorders followed until Brazil decided to occupy Puerto Alonso with a military force. The boundary dispute was finally settled at Petropolis on November 17, 1903, through the purchase by Brazil of the rubber-producing territory, south to about the ninth parallel.

Acre (disambiguation)

An acre is a unit of measurement used for areas of land.

Acre may also refer to:

Places

Other uses

Citadel

A citadel is the core fortified area of a town or city. It may be a fortress, castle, or fortified center. The term is a diminutive of "city" and thus means "little city", so called because it is a smaller part of the city of which it is the defensive core.

In a fortification with bastions, the citadel is the strongest part of the system, sometimes well inside the outer walls and bastions, but often forming part of the outer wall for the sake of economy. It is positioned to be the last line of defense, should the enemy breach the other components of the fortification system. A citadel is also a term of the third part of a medieval castle, with higher walls than the rest. It was to be the last line of defence before the keep itself.

In various countries, the citadels gained a specific name such as "Kremlin" in Russia or "Alcázar" in the Iberian Peninsula. In European cities, the term "Citadel" and "City Castle" are often used interchangeably. The term "tower" is also used in some cases such as the Tower of London and Jerusalem's Tower of David. However, the Haitian citadel, which is the largest citadel in the Western Hemisphere, is called Citadelle Laferrière or simply the "Citadel" in English.

Citadel (comics)

The Citadel is a fictional organization, a fascist empire in the DC Universe.

Fictional team history

The first Citadelian brother of Auron, and child of the goddess X'Hal adopted the technology of the Psions in order to betray his family and clone his own race of beings called Citadelians. The Citadel established an empire in the Vegan Star System, in order to conquer worlds with help from a computer called Complex-Complex. Various dictators arose to power, but Complex-Complex was always the man behind the curtain. The rulers were Lord Damyn, Komand'r, and The Chief. The reign ended in the Citadelian war when the Omega Men destroyed the Fortress Ring. An earthman named Harry Hokum (with help from Lobo) lead the Citadelians on its prison planet, and changed the name of it to New Alliance. The Branx Warriors, Spider Guild, and Gordanians reside under the earthman's command in that Star System.

Rann-Thanagar War

More recently, the Citadel has chosen to take the Rann side in the Rann-Thanagar War. Their attack on Thanagar endangers two Green Lanterns, Isamot Kol and Vath Sarn, along with dozens of innocent Saurian lives.

Citadel (software)

Citadel is the name of a bulletin board system (BBS) computer program, and of the genre of programs it inspired. Citadels were notable for their room-based structure (see below) and relatively heavy emphasis on messages and conversation as opposed to gaming and files. The first Citadel came online in 1980 with a single 300 baud modem; eventually many versions of the software, both clones and those descended from the original code base (but all usually called "Citadels"), became popular among BBS callers and sysops, particularly in areas such as the Pacific Northwest, Northern California and Upper Midwest of the United States, where development of the software was ongoing. Citadel BBSes were most popular in the late 1980s and early 1990s, but when the Internet became more accessible for online communication, Citadels began to decline. However, some versions of the software, from small community BBSes to large systems supporting thousands of simultaneous users, are still in use today. Citadel development has always been collaborative with a strong push to keep the source code in the public domain. This makes Citadel one of the oldest surviving FOSS projects.