text:
December 12

Pre-1600

 * 627 – Battle of Nineveh: A Byzantine army under Emperor Heraclius defeats Emperor Khosrau II's Persian forces, commanded by General Rhahzadh.
 * 1388 – Maria of Enghien sells the lordship of Argos and Nauplia to the Republic of Venice.

1601–1900

 * 1787 – Pennsylvania becomes the second state to ratify the US Constitution.
 * 1862 – American Civil War: USS Cairo sinks on the Yazoo River.
 * 1866 – Oaks explosion: The worst mining disaster in England kills 361 miners and rescuers.
 * 1870 – Joseph H. Rainey of South Carolina becomes the second black U.S. congressman.

1901–present

 * 1901 – Guglielmo Marconi receives the first transatlantic radio signal (the letter "S" [•••] in Morse Code), at Signal Hill in St John's, Newfoundland.
 * 1915 – Yuan Shikai declares the establishment of the Empire of China and proclaims himself Emperor.
 * 1917 – Father Edward J. Flanagan founds Boys Town as a farm village for wayward boys.
 * 1935 – The Lebensborn Project, a Nazi reproduction program, is founded by Heinrich Himmler.
 * 1937 – Second Sino-Japanese War: USS Panay incident: Japanese aircraft bomb and sink U.S. gunboat USS Panay (PR-5) on the Yangtze river in China.
 * 1939 – HMS Duchess (H64) sinks after a collision with HMS Barham (04) off the coast of Scotland with the loss of 124 men.
 * 1939  – Winter War: The Battle of Tolvajärvi, also known as the first major Finnish victory in the Winter War, begins.
 * 1941 – World War II: Fifty-four Japanese A6M Zero fighters raid Batangas Field, Philippines. Jesús Villamor and four Filipino fighter pilots fend them off; César Basa is killed.
 * 1941  – The Holocaust: Adolf Hitler declares the imminent extermination of the Jews at a meeting in the Reich Chancellery.
 * 1945 – The People's Republic of Korea is outlawed in the South, by order of the United States Army Military Government in Korea.
 * 1946 – United Nations Security Council Resolution 13 relating to acceptance of Siam (now Thailand) to the United Nations is adopted.
 * 1956 – United Nations Security Council Resolution 121 relating to acceptance of Japan to the United Nations is adopted.
 * 1963 – Kenya declares independence from Great Britain.
 * 1969 – The Piazza Fontana bombing; a bomb explodes at the headquarters of Banca Nazionale dell'Agricoltura (the National Agricultural Bank) in Piazza Fontana in Milan, Italy, killing 17 people and wounding 88. The same afternoon, three more bombs are detonated in Rome and Milan, and another is found unexploded.
 * 1979 – The 8.2 Tumaco earthquake shakes Colombia and Ecuador with a maximum Mercalli intensity of IX (Violent), killing 300–600, and generating a large tsunami.
 * 1979 – Coup d'état of December Twelfth occurs in South Korea.
 * 1985 – Arrow Air Flight 1285R, a McDonnell Douglas DC-8, crashes after takeoff in Gander, Newfoundland, killing all 256 people on board, including 236 members of the United States Army's 101st Airborne Division.
 * 1988 – The Clapham Junction rail crash kills thirty-five and injures hundreds after two collisions of three commuter trains—one of the worst train crashes in the United Kingdom.
 * 1999 – A magnitude 7.3 earthquake hits the Philippines's main island of Luzon, killing six people, injuring 40, and causing power outages that affected the capital Manila.
 * 2000 – The United States Supreme Court releases its decision in Bush v. Gore.
 * 2001 – Prime Minister of Vietnam Phan Văn Khải announces the decision on upgrading the Phong Nha–Kẻ Bàng nature reserve to a national park, providing information on projects for the conservation and development of the park and revised maps.
 * 2012 – North Korea successfully launches its first satellite, Kwangmyŏngsŏng-3 Unit 2.
 * 2015 – The Paris Agreement relating to United Nations Framework Convention on Climate Change is adopted.
 * 2021 – Dutch Formula One racing driver Max Verstappen wins the controversial 2021 Abu Dhabi Grand Prix, beating seven-time World Champion Lewis Hamilton to become the first Formula One World Champion to come from the Netherlands.

Pre-1600

 * 1526 – Álvaro de Bazán, 1st Marquis of Santa Cruz, Spanish admiral (d. 1588)

1601–1900

 * 1685 – Lodovico Giustini, Italian pianist and composer (d. 1743)
 * 1724 – Samuel Hood, 1st Viscount Hood, English admiral and politician (d. 1816)
 * 1786 – William L. Marcy, American lawyer, judge, and politician, 21st United States Secretary of State (d. 1857)
 * 1799 – Karl Bryullov, Russian painter (d. 1852)
 * 1805 – Henry Wells, American businessman, co-founded Wells Fargo and American Express (d. 1878)
 * 1806 – Stand Watie, American general (d. 1871)
 * 1812 – John Sandfield Macdonald, Canadian lawyer and politician, 1st Premier of Ontario (d. 1872)
 * 1821 – Gustave Flaubert, French novelist (d. 1880)
 * 1830 – Joseph Orville Shelby, Confederate general (d. 1897)
 * 1842 – Adolf Bötticher, German journalist and historian (d. 1901)
 * 1845 – Bruce Price, American architect, designed the American Surety Building and Bank of the Metropolis (d. 1903)
 * 1863 – Edvard Munch, Norwegian painter (d. 1944)
 * 1866 – Alfred Werner, Swiss chemist and academic, Nobel Prize laureate (d. 1919)
 * 1870 – Walter Benona Sharp, American businessman, co-founded Hughes Tool Company (d. 1912)
 * 1876 – Alvin Kraenzlein, American hurdler and runner (d. 1928)
 * 1881 – Louise Thuliez, French school teacher, resistance fighter during World War I and World War II and author (d. 1966)
 * 1893 – Edward G. Robinson, American actor (d. 1973)

1901–present

 * 1901 – Harald Kaarmann, Estonian footballer (d. 1942)
 * 1907 – Roy Douglas, English pianist and composer (d. 2015)
 * 1912 – Henry Armstrong, American boxer (d. 1988)
 * 1914 – Patrick O'Brian, English author (d. 2000)
 * 1915 – Frank Sinatra, American singer, actor, and producer (d. 1998)
 * 1918 – Joe Williams, American singer and pianist (d. 1999)
 * 1920 – Josef Doležal, Czech race walker (d. 1999)
 * 1923 – Bob Barker, American game show host and producer (d. 2023)
 * 1923  – Bob Dorough, American musician, composer, and producer (d. 2018)
 * 1923  – Emahoy Tsegué-Maryam Guèbrou, Ethiopian pianist, composer and nun (d. 2023)
 * 1924 – Ed Koch, American politician, 105th Mayor of New York City (d. 2013)
 * 1925 – Ted Kennedy, Canadian ice hockey player (d. 2009)
 * 1925  – Dattu Phadkar, Indian cricketer (d. 1985)
 * 1925  – Vladimir Shainsky, Ukrainian-Russian pianist and composer (d. 2017)
 * 1927 – Robert Noyce, American inventor and businessman, co-founded the Intel Corporation (d. 1990)
 * 1928 – Helen Frankenthaler, American painter and academic (d. 2011)
 * 1929 – Toshiko Akiyoshi, Japanese pianist and composer
 * 1932 – Bob Pettit, American basketball player and coach
 * 1933 – Christa Stubnick, German sprinter (d. 2021)
 * 1934 – Miguel de la Madrid, Mexican lawyer and politician, 52nd President of Mexico (d. 2012)
 * 1936 – Iolanda Balaș, Romanian high jumper and educator (d. 2016)
 * 1937 – Connie Francis, American singer, musician, and actress
 * 1937  – Philip Ledger, English pianist, composer, and academic (d. 2012)
 * 1940 – Sharad Pawar, Indian politician, Indian Minister of Agriculture
 * 1940  – Dionne Warwick, American singer
 * 1942 – Bob Thompson, American jazz pianist, composer and arranger
 * 1943 – Dickey Betts, American musician and songwriter (d. 2024)
 * 1943  – Grover Washington, Jr., American singer-songwriter, saxophonist, and producer (d. 1999)
 * 1945 – Tony Williams, American drummer, composer, and producer (d. 1997)
 * 1946 – Emerson Fittipaldi, Brazilian racing driver
 * 1947 – Wings Hauser, American actor
 * 1947  – Don Keith, American writer
 * 1947  – Chris Mullin, English journalist and politician
 * 1948 – Randy Smith, American basketball player (d. 2009)
 * 1948  – Colin Todd, English football player and coach
 * 1949 – Bill Nighy, English actor
 * 1949  – Marc Ravalomanana, Malagasy businessman and politician, President of Madagascar
 * 1950 – Pedro Ferriz de Con, Mexican journalist
 * 1950  – Heiner Flassbeck, German economist and academic
 * 1950  – Rajinikanth, Indian actor
 * 1950  – Billy Smith, Canadian ice hockey player, coach, and manager
 * 1950  – Gorman Thomas, American baseball player
 * 1951 – Rehman Malik, Pakistani politician, Pakistani Minister of Interior (d. 2022)
 * 1952 – Cathy Rigby, American gymnast
 * 1953 – Martin Ferguson, Australian lawyer and politician
 * 1953  – Rafael Septién, Mexican-American football player
 * 1955 – Eddy Schepers, Belgian cyclist
 * 1955  – Stephen Smith, Australian politician
 * 1956 – Johan van der Velde, Dutch cyclist
 * 1957 – Sheila E., American singer and musician
 * 1958 – Sheree J. Wilson, American actress
 * 1960 – Martina Hellmann, German discus thrower
 * 1961 – Andrey Perlov, Russian race walker
 * 1962 – Tracy Austin, American tennis player and sportscaster
 * 1962  – Arturo Barrios, Mexican-American runner
 * 1962  – Mike Golic, American football player and radio host
 * 1963 – Eduardo Castro Luque, Mexican businessman and politician (d. 2012)
 * 1964 – Haywood Jeffires, American football player and coach
 * 1964  – Sabu, American wrestler
 * 1965 – Russell Batiste Jr., American funk and R&B drummer (d. 2023)
 * 1967 – John Randle, American football player
 * 1968 – Sašo Udovič, Slovenian footballer
 * 1969 – Wilfred Kirochi, Kenyan runner
 * 1969  – Fiona May, English-Italian long jumper
 * 1969  – Michael Möllenbeck, German discus thrower
 * 1970 – Mädchen Amick, American actress and director
 * 1970  – Jennifer Connelly, American actress
 * 1970  – Regina Hall, American actress
 * 1971 – Sammy Korir, Kenyan runner
 * 1972 – Nicky Eaden, English footballer and coach
 * 1972  – Craig Field, Australian rugby league player
 * 1972  – Wilson Kipketer, Kenyan-Danish runner
 * 1972  – Georgios Theodoridis, Greek sprinter
 * 1974 – Bernard Lagat, Kenyan-American runner
 * 1974  – Nolberto Solano, Peruvian footballer and manager
 * 1975 – Mayim Bialik, American actress, neuroscientist, and author
 * 1975  – Craig Moore, Australian footballer and manager
 * 1977 – Yoel Hernández, Cuban hurdler
 * 1977  – Orlando Hudson, American baseball player
 * 1977  – Dean Macey, English decathlete and bobsledder
 * 1977  – Colin White, Canadian ice hockey player
 * 1979 – Garrett Atkins, American baseball player
 * 1979  – Nate Clements, American football player
 * 1979  – John Salmons, American basketball player
 * 1980 – Dejene Berhanu, Ethiopian runner (d. 2010)
 * 1980  – Dorin Goian, Romanian footballer
 * 1981 – Eddie Kingston, American wrestler
 * 1981  – Pedro Ríos, Spanish footballer
 * 1981  – Yuvraj Singh, Indian cricketer
 * 1981  – Stephen Warnock, English footballer
 * 1981  – Andrew Whitworth, American football player and commentator
 * 1982 – Ervin Santana, Dominican baseball player
 * 1982  – Dmitry Tursunov, Russian tennis player and coach
 * 1983 – Roni Porokara, Finnish footballer
 * 1984 – Daniel Agger, Danish footballer
 * 1985 – Pat Calathes, Greek-American basketball player
 * 1985  – Andrew Ladd, Canadian ice hockey player
 * 1986 – Daddy Birori, Rwandan footballer
 * 1986  – Përparim Hetemaj, Finnish footballer
 * 1986  – Nina Kolarič, Slovenian long jumper
 * 1986  – T. J. Ward, American football player
 * 1988 – Isaac John, New Zealand rugby league player
 * 1988  – Lonah Chemtai Salpeter, Israeli Olympic marathon runner
 * 1990 – Nixon Chepseba, Kenyan runner
 * 1990  – Dawin, American singer-songwriter
 * 1990  – Tyron Smith, American football player
 * 1991 – Joseph Leilua, Australian-Samoan rugby league player
 * 1993 – Zeli Ismail, English footballer
 * 1994 – Otto Warmbier, American student imprisoned in North Korea (d. 2017)
 * 1996 – Lucas Hedges, American actor
 * 1997 – Ed Oliver, American football player

Pre-1600

 * 884 – King Carloman II of the Franks (born c.866; hunting accident)
 * 1296 – Isabella of Mar, first wife of Robert Bruce VII (b. 1277)
 * 1572 – Loredana Marcello, Dogaressa of Venice, botanist, author

1601–1900

 * 1751 – Henry St John, 1st Viscount Bolingbroke, English philosopher and politician, Secretary at War (b. 1678)
 * 1766 – Johann Christoph Gottsched, German philosopher, author, and critic (b. 1700)
 * 1794 – Meshullam Feivush Heller, Ukrainian author (b. 1742)
 * 1803 – Prince Frederick Adolf of Sweden (b. 1750)
 * 1858 – Jacques Viger, Canadian archeologist and politician, 1st Mayor of Montreal (b. 1787)
 * 1889 – Viktor Bunyakovsky, Ukrainian-Russian mathematician and theorist (b. 1804)
 * 1894 – John Sparrow David Thompson, Canadian lawyer, judge, and politician, 4th Prime Minister of Canada (b. 1845)

1901–present

 * 1913 – Menelik II, Ethiopian emperor (b. 1844)
 * 1921 – Henrietta Swan Leavitt, American astronomer and academic (b. 1868)
 * 1923 – Raymond Radiguet, French author and poet (b. 1903)
 * 1934 – Thorleif Haug, Norwegian skier (b. 1894)
 * 1939 – Douglas Fairbanks, Sr., American actor, producer, and screenwriter (b. 1883)
 * 1941 – César Basa, Filipino lieutenant and pilot (b. 1915)
 * 1951 – Mildred Bailey, American singer (b. 1907)
 * 1958 – Albert Walsh, Canadian lawyer and politician, 1st Lieutenant Governor of Newfoundland (b. 1900)
 * 1966 – Karl Ruberl, Austrian-American swimmer (b. 1880)
 * 1968 – Tallulah Bankhead, American actress (b. 1902)
 * 1970 – Doris Blackburn, Australian politician (b. 1889)
 * 1975 – Richard Baggallay, English colonel and cricketer (b. 1884)
 * 1980 – Jean Lesage, Canadian lawyer and politician, 19th Premier of Quebec (b. 1912)
 * 1985 – Anne Baxter, American actress (b. 1923)
 * 1993 – József Antall, Hungarian historian and politician, 35th Prime Minister of Hungary (b. 1932)
 * 1994 – Stuart Roosa, American colonel, pilot, and astronaut (b. 1933)
 * 1996 – Vance Packard, American journalist, author, and critic (b. 1914)
 * 1997 – Evgenii Landis, Ukrainian-Russian mathematician and academic (b. 1921)
 * 1998 – Lawton Chiles, American soldier, lawyer, and politician, 41st Governor of Florida (b. 1930)
 * 1998  – Morris Udall, American captain and politician (b. 1922)
 * 1999 – Paul Cadmus, American painter and illustrator (b. 1904)
 * 1999  – Joseph Heller, American novelist, short story writer, and playwright(b. 1923)
 * 2001 – Ardito Desio, Italian geologist and explorer (b. 1897)
 * 2002 – Dee Brown, American historian and author (b. 1908)
 * 2003 – Heydar Aliyev, Azerbaijani general and politician, 3rd President of Azerbaijan (b. 1923)
 * 2005 – Robert Newmyer, American actor and producer (b. 1956)
 * 2005  – Annette Stroyberg, Danish actress (b. 1936)
 * 2005  – Gebran Tueni, Lebanese journalist and politician (b. 1957)
 * 2006 – Paul Arizin, American basketball player (b. 1928)
 * 2006  – Peter Boyle, American actor (b. 1935)
 * 2006   – Raymond P. Shafer, American attorney and politician, 39th Governor of Pennsylvania (b. 1917)
 * 2006  – Alan Shugart, American engineer and businessman, co-founded Seagate Technology (b. 1930)
 * 2007 – François al-Hajj, Lebanese general (b. 1953)
 * 2007  – Ike Turner, American singer-songwriter, guitarist, and producer (b. 1931)
 * 2008 – Avery Dulles, American cardinal and theologian (b. 1918)
 * 2008  – Van Johnson, American actor (b. 1916)
 * 2010 – Tom Walkinshaw, Scottish race car driver, founded Tom Walkinshaw Racing (b. 1946)
 * 2012 – Joe Allbritton, American banker, publisher, and philanthropist, founded the Allbritton Communications Company (b. 1924)
 * 2012  – David Tait, English rugby player (b. 1987)
 * 2013 – Tom Laughlin, American actor, director, screenwriter, author, educator, and activist (b. 1931)
 * 2013  – Abdul Quader Molla, Bangladeshi journalist and politician (b. 1948)
 * 2013  – Audrey Totter, American actress (b. 1917)
 * 2014 – Norman Bridwell, American author and illustrator, created Clifford the Big Red Dog (b. 1928)
 * 2014  – Ivor Grattan-Guinness, English mathematician, historian, and academic (b. 1941)
 * 2014  – Herb Plews, American baseball player (b. 1928)
 * 2015 – Frans Geurtsen, Dutch footballer (b. 1942)
 * 2015  – Evelyn S. Lieberman, American politician, White House Deputy Chief of Staff (b. 1944)
 * 2016 – Shirley Hazzard, Australian-American novelist, short story writer, and essayist (b. 1931)
 * 2017 – Ed Lee, American politician and attorney, 43rd Mayor of San Francisco (b. 1952)
 * 2017  – Pat DiNizio, American singer and songwriter  (b. 1955)
 * 2019 – Danny Aiello, American actor (b. 1933)
 * 2020 – John le Carré, English author (b. 1931)
 * 2020  – Ann Reinking, American actress, dancer, and choreographer (b. 1949)
 * 2021 – Vicente Fernández, Mexican actor, ranchera singer, and film producer (b, 1940)
 * 2021 – Bernie Fowler, American politician and environmental advocate (b. 1924)
 * 2021 – Maʻafu Tukuiʻaulahi, Tongan politician and military officer, Deputy Prime Minister (b. 1955)

Holidays and observances

 * Christian feast day:
 * Corentin of Quimper
 * Jane Frances de Chantal
 * Edburga of Minster-in-Thanet
 * Finnian of Clonard
 * Thomas Holland
 * Ida of Nivelles
 * Peter the Aleut
 * Vicelinus
 * December 12 (Eastern Orthodox liturgics)
 * Constitution Day (Russia)
 * Day of Neutrality (Turkmenistan)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: December 12


text: Talk:Dianic Wicca

title: Talk:Dianic Wicca


text:
Door

A door is a hinged or otherwise movable barrier that allows ingress (entry) into and egress (exit) from an enclosure. The created opening in the wall is a doorway or portal. A door's essential and primary purpose is to provide security by controlling access to the doorway (portal). Conventionally, it is a panel that fits into the doorway of a building, room, or vehicle. Doors are generally made of a material suited to the door's task. They are commonly attached by hinges, but can move by other means, such as slides or counterbalancing.

The door may be able to move in various ways (at angles away from the doorway/portal, by sliding on a plane parallel to the frame, by folding in angles on a parallel plane, or by spinning along an axis at the center of the frame) to allow or prevent ingress or egress. In most cases, a door's interior matches its exterior side. But in other cases (e.g., a vehicle door) the two sides are radically different.

Many doors incorporate locking mechanisms to ensure that only some people can open them (such as with a key). Doors may have devices such as knockers or doorbells by which people outside announce their presence. Apart from providing access into and out of a space, doors may have the secondary functions of ensuring privacy by preventing unwanted attention from outsiders, of separating areas with different functions, of allowing light to pass into and out of a space, of controlling ventilation or air drafts so that interiors may be more effectively heated or cooled, of dampening noise, and of blocking the spread of fire.

Doors can have aesthetic, symbolic, ritualistic purposes. Receiving the key to a door can signify a change in status from outsider to insider. Doors and doorways frequently appear in literature and the arts with metaphorical or allegorical import as a portent of change.

History
The earliest recorded doors appear in the paintings of Egyptian tombs, which show them as single or double doors, each of a single piece of wood. People may have believed these were doors to the afterlife, and some include designs of the afterlife. In Egypt, where the climate is intensely dry, doors were not framed against warping, but in other countries required framed doors—which, according to Vitruvius (iv. 6.) was done with stiles (sea/si) and rails (see: Frame and panel), the enclosed panels filled with tympana set in grooves in the stiles and rails. The stiles were the vertical boards, one of which, tenoned or hinged, is known as the hanging stile, the other as the middle or meeting stile. The horizontal cross pieces are the top rail, bottom rail, and middle or intermediate rails.

The most ancient doors were made of timber, such as those referred to in the Biblical depiction of King Solomon's temple being in olive wood (I Kings vi. 31–35), which were carved and overlaid with gold. The doors that Homer mentions appear to have been cased in silver or brass. Besides olive wood, elm, cedar, oak and cypress were used. Two doors over 5,000 years old have been found by archaeologists near Zürich, Switzerland.

Ancient doors were hung by pintles at the top and bottom of the hanging stile, which worked in sockets in the lintel and sill, the latter in some hard stone such as basalt or granite. Those Hilprecht found at Nippur, dating from 2000 BC, were in dolerite. The tenons of the gates at Balawat were sheathed with bronze (now in the British Museum). These doors or gates were hung in two leaves, each about 2.54 m wide and 8.2 m high; they were encased with bronze bands or strips, 25.4 cm high, covered with repoussé decoration of figures. The wood doors would seem to have been about 7.62 cm thick, but the hanging stile was over 360 mm diameter. Other sheathings of various sizes in bronze show this was a universal method adopted to protect the wood pivots. In the Hauran in Syria where timber is scarce, the doors were made of stone, and one measuring 1.63 by is in the British Museum; the band on the meeting stile shows that it was one of the leaves of a double door. At Kuffeir near Bostra in Syria, Burckhardt found stone doors, 2.74 to 3.048 m high, being the entrance doors of the town. In Etruria many stone doors are referred to by Dennis.

Ancient Greek and Roman doors were either single doors, double doors, triple doors, sliding doors or folding doors, in the last case the leaves were hinged and folded back. In the tomb of Theron at Agrigentum there is a single four-panel door carved in stone. In the Blundell collection is a bas-relief of a temple with double doors, each leaf with five panels. Among existing examples, the bronze doors in the church of SS. Cosmas and Damiano, in Rome, are important examples of Roman metal work of the best period; they are in two leaves, each with two panels, and are framed in bronze. Those of the Pantheon are similar in design, with narrow horizontal panels in addition, at the top, bottom and middle. Two other bronze doors of the Roman period are in the Lateran Basilica.

The Greek scholar Heron of Alexandria created the earliest known automatic door in the first century AD during the era of Roman Egypt. The first foot-sensor-activated automatic door was made in China during the reign of Emperor Yang of Sui (r. 604–618), who had one installed for his royal library. Gates powered by water featured in illustrations of the automatons of the Arab inventor Al-Jazari.

Copper and its alloys were integral in medieval architecture. The doors of the church of the Nativity at Bethlehem (6th century) are covered with plates of bronze, cut out in patterns. Those of Hagia Sophia at Constantinople, of the eighth and ninth century, are wrought in bronze, and the west doors of the cathedral of Aix-la-Chapelle (9th century), of similar manufacture, were probably brought from Constantinople, as also some of those in St. Marks, Venice. The bronze doors on the Aachen Cathedral in Germany date back to about 800 AD. Bronze baptistery doors at the Cathedral of Florence were completed in 1423 by Ghiberti. (For more information, see: Copper in architecture).

Of the 11th and 12th centuries there are numerous examples of bronze doors, the earliest being one at Hildesheim, Germany (1015). The Hildesheim design affected the concept of Gniezno door in Poland. Of others in South Italy and Sicily, the following are the finest: in Sant'Andrea, Amalfi (1060); Salerno (1099); Canosa di Puglia (1111); Troia, two doors (1119 and 1124); Ravello (1179), by Barisano of Trani, who also made doors for Trani cathedral; and in Monreale and Pisa cathedrals, by Bonano of Pisa. In all these cases the hanging stile had pivots at the top and bottom. The exact period when the builder moved to the hinge is unknown, but the change apparently brought about another method of strengthening and decorating doors—wrought-iron bands of various designs. As a rule, three bands with ornamental work constitute the hinges, with rings outside the hanging stiles that fit on vertical tenons set into the masonry or wooden frame. There is an early example of the 12th century in Lincoln. In France, the metalwork of the doors of Notre Dame at Paris is a beautiful example, but many others exist throughout France and England.

In Italy, celebrated doors include those of the Battistero di San Giovanni (Florence), which are all in bronze—including the door frames. The modeling of the figures, birds and foliage of the south doorway, by Andrea Pisano (1330), and of the east doorway by Ghiberti (1425–1452), are of great beauty. In the north door (1402–1424), Ghiberti adopted the same scheme of design for the paneling and figure subjects as Andrea Pisano, but in the east door, the rectangular panels are all filled, with bas-reliefs that illustrate Scripture subjects and innumerable figures. These may the gates of Paradise of which Michelangelo speaks.

Doors of the mosques in Cairo were of two kinds: those externally cased with sheets of bronze or iron, cut in decorative patterns, and incised or inlaid, with bosses in relief; and those of wood-framed with interlaced square and diamond designs. The latter design is Coptic in origin. The doors of the palace at Palermo, which were made by Saracenic workmen for the Normans, are fine examples in good preservation. A somewhat similar decorative class of door is found in Verona, where the edges of the stiles and rails are beveled and notched.

In the Renaissance period, Italian doors are quite simple, their architects trusting more to the doorways for effect; but in France and Germany the contrary is the case, the doors being elaborately carved, especially in the Louis XIV and Louis XV periods, and sometimes with architectural features such as columns and entablatures with pediment and niches, the doorway being in plain masonry. While in Italy the tendency was to give scale by increasing the number of panels, in France the contrary seems to have been the rule; and one of the great doors at Fontainebleau, which is in two leaves, is entirely carried out as if consisting of one great panel only.

The earliest Renaissance doors in France are those of the cathedral of St. Sauveur at Aix (1503). In the lower panels there are figures 3 ft. high in Gothic niches, and in the upper panels a double range of niches with figures about 2 ft. high with canopies over them, all carved in cedar. The south door of Beauvais Cathedral is in some respects the finest in France; the upper panels are carved in high relief with figure subjects and canopies over them. The doors of the church at Gisors (1575) are carved with figures in niches subdivided by classic pilasters superimposed. In St. Maclou at Rouen are three magnificently carved doors; those by Jean Goujon have figures in niches on each side, and others in a group of great beauty in the center. The other doors, probably about forty to fifty years later, are enriched with bas-reliefs, landscapes, figures and elaborate interlaced borders.

NASA's Vehicle Assembly Building at the Kennedy Space Center contains the four largest doors. The Vehicle Assembly Building was originally built for the assembly of the Apollo missions' Saturn vehicles and was then used to support Space Shuttle operations. Each of the four doors are 139 m high.

The oldest door in England can be found in Westminster Abbey and dates from 1050. In England in the 17th century the door panels were raised with bolection or projecting moldings, sometimes richly carved, around them; in the 18th century the moldings worked on the stiles and rails were carved with the egg-and-dart ornament.

Design and styles

There are many kinds of doors, with different purposes.

 * The most common type is the single-leaf door, which consists of a single rigid panel that fills the doorway. There are many variations on this basic design, such as the double-leaf door or double door and French windows, which have two adjacent independent panels hinged on each side of the doorway.

 * A half door or Dutch door or stable door is divided in half horizontally. Traditionally the top half opens so a worker can feed a horse or other animal while the bottom half remains closed to keep the animal inside. This style of door has been adapted for homes.
 * Saloon doors are a pair of lightweight swing doors often found in public bars, and especially associated with the American west. Saloon doors, also known as cafe doors, often use bidirectional hinges that close the door regardless of which direction it opens by incorporating springs. Saloon doors that only extend from knee-level to chest-level are known as batwing doors.
 * A blind door, Gibb door, or jib door has no visible trim or operable components. It blends with the adjacent wall in all finishes, to appear as part of the wall—a disguised door.

 * A French door consists of a frame around one or more transparent or translucent panels (called lights or lites) that may be installed singly, in matching pairs, or even as series. A matching pair of these doors is called a French window, as it resembles a door-height casement window. When a pair of French doors is used as a French window, the application does not generally include a central mullion (as do some casement window pairs), thus allowing a wider unobstructed opening. The frame typically requires a weather strip at floor level and where the doors meet to prevent water ingress. An espagnolette bolt may let the head and foot of each door be secured in one movement. The slender window joinery maximizes light into the room and minimizes the visual impact of the doorway joinery when considered externally. The doors of a French window often open outward onto a balconet, balcony, porch, or terrace and they may provide an entrance to a garden.
 * A louvered door has fixed or movable wooden fins (often called slats or louvers) which permit open ventilation while preserving privacy and preventing the passage of light to the interior. Being relatively weak structures, they are most commonly used for wardrobes and drying rooms, where security is of less importance than good ventilation, although a very similar structure is commonly used to form window shutters. Double louvred doors were introduced into Seagate, built in Florida in 1929 by Gwendolyn and Powel Crosley, that provided the desired circulation of air with an added degree of privacy in that it is impossible to see through the fins in any direction.
 * A composite door is a single leaf door that can be solid or with glass, and is usually filled with high density foam. In the United Kingdom, composite doors are commonly certified to BS PAS 23/24 and be compliant with Secured by Design, an official UK police initiative.
 * A steel security door is one which is made from strong steel, often for use on vaults and safe rooms to withstand attack. These may also be fitted with wooden outer panels to resemble standard internal and external doors.
 * A flush door is a completely smooth door, having plywood or MDF fixed over a light timber frame, the hollow parts of which are often filled with a cardboard core material. Skins can also be made out of hardboards, the first of which was invented by William H Mason in 1924. Called Masonite, its construction involved pressing and steaming wood chips into boards. Flush doors are most commonly employed in the interior of a dwelling, although slightly more substantial versions are occasionally used as exterior doors, especially within hotels and other buildings containing many independent dwellings.
 * A moulded door has the same structure as that of flush door. The only difference is that the surface material is a moulded skin made of MDF. Skins can also be made out of hardboards.
 * A ledge and brace door often called board and batten doors are made from multiple vertical boards fixed together by two or more horizontal timbers called ledges (or battens) and sometimes kept square by additional diagonal timbers called braces.
 * A wicket door is a pedestrian door built into a much larger door allowing access without requiring the opening of the larger door. Examples might be found on the ceremonial door of a cathedral or in a large vehicle door in a garage or hangar.
 * A bifold door is a unit that has several sections, folding in pairs. Wood is the most common material, and doors may also be metal or glass. Bifolds are most commonly made for closets, but may also be used as units between rooms. Bi-fold doors are essentially now doors that let the outside in. They open in concert; where the panels fold up against one another and are pushed together when opened. The main door panel (often known as the traffic door) is accompanied by a stack of panels that fold very neatly against one another when opened fully, which almost look like room dividers.
 * A sliding glass door, sometimes called an Arcadia door or patio door, is a door made of glass that slides open and sometimes has a screen (a removable metal mesh that covers the door).
 * Australian doors are a pair of plywood swinging doors often found in Australian public houses. These doors are generally red or brown in color and bear a resemblance to the more formal doors found in other British Colonies' public houses.
 * A false door is a wall decoration with the appearance of a window. In ancient Egyptian architecture, this was a common element in a tomb, the false door representing a gate to the afterlife. They can also be found in the funerary architecture of the desert tribes (e.g., Libyan Ghirza).

Hinged
Most doors are hinged along one side to allow the door to pivot away from the doorway in one direction, but not the other. The axis of rotation is usually vertical. In some cases, such as hinged garage doors, the axis may be horizontal, above the door opening.

Doors can be hinged so that the axis of rotation is not in the plane of the door to reduce the space required on the side to which the door opens. This requires a mechanism so that the axis of rotation is on the side other than that in which the door opens. This is sometimes the case in trains or airplanes, such as for the door to the toilet, which opens inward.

 * A swing door has special single-action hinges that allow it to open either outward or inward, and is usually sprung to keep it closed.
 * French doors are derived from the French design called the casement door. It is a door with lites where all or some panels would be in a casement door. A French door traditionally has a moulded panel at the bottom of the door. It is called a French window when used in a pair as double-leaved doors with large glass panels in each door leaf, and in which the doors may swing out (typically) as well as in.
 * A double-acting door, patented in 1880 by the Dutch-American engineer Lorenz Bommer, swings both ways. They are often used in areas where many people are likely to pass through, such as restaurant kitchens.
 * A Dutch door or stable door consists of two halves. The top half operates independently from the bottom half. A variant exists in which opening the top part separately is possible, but because the lower part has a lip on the inside, closing the top part, while leaving the lower part open, is not.
 * A garden door resembles a French window (with lites), but is more secure because only one door is operable. The hinge of the operating door is next to the adjacent fixed door and the latch is located at the wall opening jamb rather than between the two doors or with the use of an espagnolette bolt.
 * A Lev door or convection door is an internal floor-to-ceiling (full height) door, consisting of a standard door leaf and an upper leaf in place of the usual header wall. The leaves may or may not be separated by a transom. The doors enable effective convection of warm air.

Sliding
It is often useful to have doors which slide along tracks, often for space or aesthetic considerations.

A bypass door is a door unit that has two or more sections. The doors can slide in either direction along one axis on parallel overhead tracks, sliding past each other. They are most commonly used in closets to provide access one side of the closet at a time. Doors in a bypass unit overlap slightly when viewed from the front so they do not have a visible gap when closed.

Doors which slide inside a wall cavity are called pocket doors. This type of door is used in tight spaces where privacy is also required. The door slab is mounted to roller and a track at the top of the door and slides inside a wall.

Sliding glass doors are common in many houses, particularly as an entrance to the backyard. Such doors are also popular for use for the entrances to commercial structures, although they are not counted as fire exit doors. The door that moves is called the "active leaf", while the door that remains fixed is called the "inactive leaf".

Rotating

 * A revolving door has several wings or leaves, generally four, radiating from a central shaft, forming compartments that rotate about a vertical axis. A revolving door allows people to pass in both directions without colliding, and forms an airlock maintaining a seal between inside and out.
 * A pivot door, instead of hinges, is supported on a bearing some distance away from the edge, so that there is more or less of a gap on the pivot side as well as the opening side. In some cases the pivot is central, creating two equal openings.

High-speed
A high-speed door is a very fast door some with opening speeds of up to 4 m/s, mainly used in the industrial sector where the speed of a door has an effect on production logistics, temperature and pressure control. High-speed cleanroom doors, usually consisting of a transparent material on a stainless steel frame, are used in pharmaceutical industries to allow passage between work areas while admitting minimal contaminants. The powerful high-speed doors have a smooth surface structure and no protruding edges, allowing minimal particle retention and easy cleaning.

High-speed doors are made to handle a high number of openings, generally more than 200,000 a year. They must be built with heavy-duty parts and counterbalance systems for speed enhancement and emergency opening function. The door curtain was originally made of PVC, but was later also developed in aluminium and acrylic glass sections. High-speed refrigeration and cold-room doors with excellent insulation values have also been introduced for green and energy-saving requirements.

In North America, the Door and Access Systems Manufacturing Association (DASMA) defines high-performance doors as non-residential powered doors characterized by rolling, folding, sliding or swinging action, that are either high-cycle (minimum 100 cycles/day) or high-speed (minimum 20 inches (508 mm)/second), and two out of three of the following: made-to-order for exact size and custom features, able to withstand equipment impact (break-away if accidentally hit by vehicle), or able to sustain heavy use with minimal maintenance.

Automatic
Automatically opening doors are powered open and closed either by electricity, spring, or both. There are several methods by which an automatically opening door is activated:

 * 1) A sensor detects traffic is approaching. Sensors for automatic doors are generally:
 * 2) * A pressure sensor – e.g., a floor mat which reacts to the pressure of someone standing on it.
 * 3) * An infrared curtain or beam which shines invisible light onto sensors; if someone or something blocks the beam the door is triggered open.
 * 4) * A motion sensor which uses low-power microwave radar for the same effect.
 * 5) * A remote sensor (e.g. based on infrared or radio waves) can be triggered by a portable remote control, or is installed inside a vehicle. These are popular for garage doors.
 * 6) A switch is operated manually, perhaps after security checks. This can be a push button switch or a swipe card.
 * 7) The act of pushing or pulling the door triggers the open and close cycle. These are also known as power-assisted doors.

In addition to activation sensors, automatically opening doors are generally fitted with safety sensors. These are usually an infrared curtain or beam, but can be a pressure mat fitted on the swing side of the door. The safety sensor prevents the door from colliding with an object by stopping or slowing its motion. A mechanism in modern automatic doors ensures that the door can open in a power failure.

Other

 * Up-and-over or overhead doors are often used in garages. Instead of hinges, it has a mechanism, often counterbalanced or sprung, so it can lift and rest horizontally above the opening. A roller shutter or sectional overhead door is one variant of this type.
 * A tambour door or roller door is an up-and-over door made of narrow horizontal slats that rolls up and down by sliding along vertical tracks; it is typically found in entertainment centres and cabinets.
 * Rebated doors, a term chiefly used in Britain, are double doors with a lip or overlap (i.e. a rabbet) on the vertical edge(s) where they meet. Fire-rating can be achieved with an applied edge-guard or astragal molding on the meeting stile, in accordance with the American fire door.

Applications

Architectural doors have numerous general and specialized uses. Doors are generally used to separate interior spaces (closets, rooms, etc.) for convenience, privacy, safety, and security reasons. Doors are also used to secure passages into a building from the exterior, for reasons of climate control and safety.

Doors also are applied in more specialized cases:
 * A blast-proof door is constructed to allow access to a structure as well as to provide protection from the force of explosions.
 * A garden door is any door that opens to a backyard or garden. This term is often used specifically for French windows, double French doors (with lites instead of panels), in place of a sliding glass door. The term also may refer to what is known as patio doors.
 * A jib door is a concealed door, whose surface reflects the moldings and finishes of the wall. These were used in historic English houses, mainly as servants' doors.
 * A pet door (also known as a cat flap or dog door) is an opening in a door to allow pets to enter and exit without the main door's being opened. It may be simply covered by a rubber flap, or it may be an actual door hinged on the top that the pet can push through. Pet doors may be mounted in a sliding glass door as a new (permanent or temporary) panel. Pet doors may be unidirectional, only allowing pets to exit. Additionally, pet doors may be electronic, only allowing animals with a special electronic tag to enter.
 * A trapdoor is a door that is oriented horizontally in a ceiling or floor, often accessed via a ladder.
 * A water door or water entrance, such as those used in Venice, Italy, is a door leading from a building built on the water, such as a canal, to the water itself where, for example, one may enter or exit a private boat or water taxi.

Paneling
Panel doors, also called stile and rail doors, are built with frame and panel construction. EN 12519 is describing the terms which are officially used in European Member States. The main parts are listed below:
 * Stiles – Vertical boards that run the full height of a door and compose its right and left edges. The hinges are mounted to the fixed side (known as the "hanging stile"), and the handle, lock, bolt or latch are mounted on the swinging side (known as the "latch stile").
 * Rails – Horizontal boards at the top, bottom, and optionally in the middle of a door that join the two stiles and split the door into two or more rows of panels. The "top rail" and "bottom rail" are named for their positions. The bottom rail is also known as "kick rail". A middle rail at the height of the bolt is known as the "lock rail", other middle rails are commonly known as "cross rails".
 * Mullions – Smaller optional vertical boards that run between two rails, and split the door into two or more columns of panels, the term is used sometimes for verticals in doors, but more often (UK and Australia) it refers to verticals in windows.
 * Muntin – Optional vertical members that divide the door into smaller panels.
 * Panels – Large, wider boards used to fill the space between the stiles, rails, and mullions. The panels typically fit into grooves in the other pieces, and help to keep the door rigid. Panels may be flat, or in raised panel designs. Can be glued in or stay as a floating panel.
 * Light – a piece of glass used in place of a panel, essentially giving the door a window.

Board battening
Also known as ledges and braced, board and batten doors are an older design consisting primarily of vertical slats:
 * Planks – Boards wider than 9" that extend the full height of the door, and are placed side by side filling the door's width.
 * Ledges and braces – Ledges extend horizontally across the door which the boards are affixed to. The ledges hold the planks together. When diagonally they are called braces which prevent the door from skewing. On some doors, especially antique ones, the ledges are replaced with iron bars that are often built into the hinges as extensions of the door-side plates.

Ledging and bracing
As board and Batten doors.

Impact resistance
Impact-resistant doors have rounded stile edges to dissipate energy and minimize edge chipping, scratching and denting. The formed edges are often made of an engineered material. Impact-resistant doors excel in high traffic areas such as hospitals, schools, hotels and coastal areas.

Frame and fill
This type consists of a solid timber frame, filled on one face, face with tongue and groove boards. Quite often used externally with the boards on the weather face.

Flushing
Flushing of a door means the door is flush with the face of the wall on either side.

Moulding

 * Stiles and rails – As above, but usually smaller. They form the outside edges of the door.
 * Core material: Material within the door used simply to fill space, provide rigidity and reduce druminess.
 * Hollow-core – Often consists of a lattice or honeycomb made of corrugated cardboard, extruded polystyrene foam, or thin wooden slats. Can also be built with staggered wooden blocks. Hollow-core molded doors are commonly used as interior doors.
 * Lock block – A solid block of wood mounted within a hollow-core flush door near the bolt to provide a solid and stable location for mounting the door's hardware.
 * Stave-core – Consists of wooden slats stacked upon one another in a manner similar to a board & batten door (though the slats are usually thinner) or the wooden-block hollow-core (except that the space is entirely filled).
 * Solid-core – Can consist of low-density particle board or foam used to completely fill the space within the door. Solid-core flush doors (especially foam-core ones) are commonly used as exterior doors because they provide more insulation and strength.
 * Skin – The front and back faces of the door are covered with HDF/MDF skins.

Swing direction
Generally, door swings, or handing, are determined while standing on the outside or less secure side of the door while facing the door (i.e., standing on the side requiring a key to open, going from outside to inside, or from public to private).

It is important to get the hand and swing correct on exterior doors, as the transom is usually sloped and sealed to resist water entry, and properly drain. In some custom millwork (or with some master carpenters), the manufacture or installer bevels the leading edge (the first edge to meet the jamb as the door closes) so that the door fits tight without binding. Specifying an incorrect hand or swing can make the door bind, not close properly, or leak. Fixing this error is expensive or time-consuming. In North America, many doors now come with factory-installed hinges, pre-hung on the jamb and sills.

While facing the door from the outside or less secure side, if the hinge is on the right side of the door, the door is "right handed"; or if the hinge is on the left, it is "left handed". If the door swings toward you, it is "reverse swing"; or if the door swings away from you, it is "normal swing".

In other words:
 * In the United States:
 * Left hand hinge (LHH): Standing outside (or on the less secure side, or on the public side of the door), the hinges are on the left and the door opens in (away from you).
 * Right hand hinge (RHH): Standing outside (or on the less secure side), the hinges are on the right and the door opens in (away from you).
 * Left hand reverse (LHR): Standing outside the house (or on the less secure side), the hinges are on the left, knob on right, on opening the door it swings toward you (i.e. the door swings open toward the outside, or "outswing")
 * Right hand reverse (RHR): Standing outside the house (i.e. on the less secure side), the hinges are on the right, knob on left, opening the door by pulling the door toward you (i.e. open swings to the outside, or "outswing")
 * In Europe:
 * One of the oldest DIN standard applies: DIN 107 "Building construction; identification of right and left side" (first 1922–05, current 1974–04) defines that doors are categorized from the side where the door hinges can be seen. If the hinges are on the left, it is a DIN Left door (DIN links, DIN gauche), if the hinges are on the right, it is a DIN Right door (DIN rechts, DIN droite). The DIN Right and DIN Left marking are also used to categorize matching installation material such as mortise locks (referenced in DIN 107). The European Standard DIN EN 12519 "Windows and pedestrian doors. Terminology" includes these definitions of orientation.
 * In Australia:
 * The "refrigerator rule" applies, and a refrigerator door is not opened from the inside. If the hinges are on the right then it is a right hand (or right hung) door. (Australian Standards for Installation of Timber Doorsets, AS 1909–1984 pg 6.)
 * In public buildings, exterior doors open to the outside to comply with applicable fire codes. In a fire, a door that opens inward could cause a crush of people who cannot open it.

Main materials
New exterior doors are largely defined by the type of materials they are made from: wood, steel, fiberglass, UPVC/vinyl, aluminum, composite, glass (patio doors), etc.

Wooden doors – including solid wood doors – are a top choice for many homeowners, largely because of the aesthetic qualities of wood. Many wood doors are custom-made, but they have several downsides: their price, their maintenance requirements (regular painting and staining) and their limited insulating value (R-5 to R-6, not including the effects of the glass elements of the doors). Wood doors often have an overhang requirement to maintain a warranty. An overhang is a roof, porch area or awning that helps to protect the door and its finish from UV rays.

Steel doors are another major type of residential front doors; most of them come with a polyurethane or other type of foam insulation core – a critical factor in a building's overall comfort and efficiency. Steel doors mostly in default comes along with frame and lock system, which is a high cost efficiency factor compared to wooden doors.

Most modern exterior walls provide thermal insulation and energy efficiency, which can be indicated by the Energy Star label or the passive house standards. Premium composite (including steel doors with a thick core of polyurethane or other foam), fiberglass and vinyl doors benefit from the materials they are made from, from a thermal perspective.

Insulation and weatherstripping
But there are very few door models with an R-value close to 10 (the R-value measures how well a barrier resists the conductive flow of heat). This is far less than the R-40 walls or the R-50 ceilings of super-insulated buildings – passive solar and zero-energy buildings. Typical doors are not thick enough to provide very high levels of energy efficiency.

Many doors may have good R-values at their center, but their overall energy efficiency is reduced because of the presence of glass and reinforcing elements, or because of poor weatherstripping and the way the door is manufactured.

Door weatherstripping is particularly important for energy efficiency. German-made passive house doors use multiple weatherstrips, including magnetic strips, to meet higher standards. These weatherstrips reduce energy losses due to air leakage.

United States
Standard door sizes in the US run along 2" increments. Customary sizes have a height of 78 or and a width of 18 ,. Most residential passage (room to room) doors are 30 x.

A standard US residential (exterior) door size is 36 ×. Interior doors for wheelchair access must also have a minimum width of 36 in. Residential interior doors, as well as the doors of many small stores, offices, and other light commercial buildings, are often somewhat smaller than the doors of larger commercial buildings, public buildings, and grand homes. Older buildings often have smaller doors.

Thickness: Most pre-fabricated doors are 1 3/8" thick (for interior doors) or 1 3/4" (exterior).

Closets: small spaces such as closets, dressing rooms, half-baths, storage rooms, cellars, etc. often are accessed through doors smaller than passage doors in one or both dimensions but similar in design.

Garages: Garage doors are generally 84" (7 feet; 2134 mm) or 96" (8 feet; 2438 mm) wide for a single-car opening. Two car garage doors (sometimes called double car doors) are a single door 192" (16 feet; 4877 mm). Because of size and weight these doors are usually sectional. That is split into four or five horizontal sections so that they can be raised more easily and do not require a lot of additional space above the door when opening and closing. Single piece double garage doors are common in some older homes.

Europe
Standard DIN doors are defined in DIN 18101 (published 1955–07, 1985–01, 2014–08). Door sizes are also given in the construction standard for wooden door panels (DIN 68706–1). The DIN commission created the harmonized European standard DIN EN 14351-1 for exterior doors and DIN EN 14351-2 for interior doors (published 2006–07, 2010–08), which define requirements for the CE marking and provide standard sizes by examples in the appendix.

The DIN 18101 standard has a normative size (Nennmaß) slightly larger than the panel size (Türblatt) as the standard derives the panel sizes from the normative size being different single door vs double door and molded vs unmolded doors. DIN 18101/1985 defines interior single molded doors to have a common panel height of 1985 mm (normativ height 2010 mm) at panel widths of 610 mm, 735 mm, 860 mm, 985 mm, 1110 mm, plus a larger door panel size of 1110 mm x 2110 mm. The newer DIN 18101/2014 drops the definition of just five standard door sizes in favor of a basic raster running along 125 mm increments where the height and width are independent. Panel width may be in the range 485 mm to 1360 mmm, and the height may be in the range of 1610 mm to 2735 mm. The most common interior door is 860 x.

Doorways

When framed in wood for snug fitting of a door, the doorway consists of two vertical jambs on either side, a lintel or head jamb at the top, and perhaps a threshold at the bottom. When a door has more than one movable section, one of the sections may be called a leaf. See door furniture for a discussion of attachments to doors such as door handles, doorknobs, and door knockers.
 * Lintel – A horizontal beam above a door that supports the wall above it. (Also known as a header)
 * Jambs or legs – The vertical posts that form the sides of a door frame, where the hinges are mounted, and with which the bolt interacts.
 * Door casing, door frame, or chambranle – formed by the lintel and the two jambs.
 * Sill (for exterior doors) – A horizontal sill plate below the door that supports the door frame. Similar to a window sill but for a door
 * Threshold (for exterior doors) – A horizontal plate below the door that bridges the crack between the interior floor and the sill.
 * Doorstop – a thin slat built inside the frame to prevent a door from swinging through when closed, an act which might break the hinges.
 * Architrave – The decorative molding that outlines a door frame, called an Archivolt if the door is arched. Sometimes called brickmold in North America.
 * Doormat (also called door mat) – a mat placed typically in front of or behind a door of a home. This practice originated so that mud and dirt would be less prevalent on floors inside a building.

Related hardware
Door furniture or hardware refers to any of the items that are attached to a door or a drawer to enhance its functionality or appearance. This includes items such as hinges, handles, door stops, etc.

Safety
Door safety relates to prevention of door-related accidents. Such accidents take place in various forms, and in a number of locations; ranging from car doors to garage doors. Accidents vary in severity and frequency. According to the National Safety Council in the United States, around 300,000 door-related injuries occur every year.

The types of accidents vary from relatively minor cases where doors cause damage to other objects, such as walls, to serious cases resulting in human injury, particularly to fingers, hands, and feet. A closing door can exert up to 40 tons per square inch of pressure between the hinges. Because of the number of accidents taking place, there has been a surge in the number of lawsuits. Thus organisations may be at risk when car doors or doors within buildings are unprotected.

According to the US General Services Administration, discussing child care centres:

"...It is essential that children's fingers be protected from being crushed or otherwise injured in the hinge space of a swinging door or gate. There are simple devices available to attach to the hinge side, ensuring that this type of injury does not occur. As the door closes, the hand is pushed out of the opening, away from harm. In addition, young children are vulnerable to injury when they fall against the other (hinged) side of doors and gates, striking projected hinges. Piano hinges are not recommended to alleviate this problem as they tend to sag over time with heavy use. Instead, an inexpensive device fitting over hinges is available on the market and should be used to ensure safety..."

Opening direction
Whenever a door is opened outward, there is a risk that it could strike another person. In many cases this can be avoided by architectural design which favors doors which open inward to rooms (from the perspective of a common area such as a corridor, the door opens outward). In cases where this is infeasible, it may be possible to avoid an accident by placing vision panels in the door.

Inward-hinged doors can also escalate an accident by preventing people from escaping the building: people inside the building may press against the doors, and thus prevent the doors from opening. Related accidents include:
 * Grue Church fire: Grue, Norway in 1822
 * Victoria Hall Disaster: Sunderland, UK in 1883
 * Glen Cinema disaster: Paisley, UK in 1929
 * Cocoanut Grove fire: Boston, USA in 1942

Today, the exterior doors of most large (especially public) buildings open outward, while interior doors such as doors to individual rooms, offices, suites, etc. open inward, as do many exterior doors of houses, particularly in North America.

Stops
Doorstops are simple devices that prevent a door from contacting and possibly damaging another object (typically a wall). They may either absorb the force of a moving door, or hold the door against unintended motion.

Guards
Door guards (hinge guards, anti-finger trapping devices, or finger guards) help prevent finger trapping accidents, as doors pose a risk to children, especially when closing. Door guards protect fingers in door hinges by covering the hinge-side gap of an open door, typically with a piece of rubber or plastic that wraps from the door frame to the door. Other door safety products eject the fingers from the push side of the door as it closes.

There are various levels of door protection. Anti-finger trapping devices in front may leave the rear hinge pin side of doors unprotected. Full door protection uses front and rear anti-finger trapping devices and ensures the hinge side of a door is fully isolated. A risk assessment of the door determines the appropriate level of protection.

There is also handle-side door protection, which prevents the door from slamming shut on the frame, which can cause injury to fingers/hands.

Glass
Glass doors pose the risk of unintentional collision if a person is unaware there is a door, or thinks it is open when it is not. This risk is greater with sliding glass doors because they often have large single panes that are hard to see. Stickers or other types of warnings on the glass surface make it more visible and help prevent injury. In the UK, Regulation 14 of the Workplace (Health and Safety Regulations) 1992 requires that builders mark windows and glass doors to make them conspicuous. Australian Standards: AS1288 and AS2208 require that glass doors be made of laminated, tempered, or toughened glass.

Fire
Buildings often have special purpose doors that automatically close to prevent the spread of fire and smoke. Fire doors that are improperly installed or tampered with can increase risk during a fire. Sometimes, door closer mechanisms ensure fire doors remain closed.

An additional fire risk is that doors may prevent access to emergency services personnel coming to fight the fire and rescue occupants, etc. Fire fighters must use door breaching techniques in these situations to gain access.

Doors in public buildings often have panic bars, which open the door in response to anyone pressing against the bar from the inside in the event of a fire or other emergency.

Automobiles
Vehicle doors present an increased risk of trapping hands or fingers due to the proximity of occupants.

Bicyclists cycling on public roads risk dooring: collision with an abruptly opened vehicle door. Because cyclists often ride near parked cars alongside the road, they are particularly vulnerable.

Aircraft
In aircraft, doors in a pressurized cabin or cargo hold could pose risk if they open during flight, causing decompression. Air may rush out of the fuselage with sufficient velocity to eject unsecured occupants, cargo, and other items, and drastic pressure differences between compartments may cause aircraft floors or other interior partitions to fail. These concerns are typically mitigated with plug doors, which open inward. They are secured into their door frames by the difference in air pressure. Most cabin doors and emergency exits are of this type, but cargo doors typically open outward to maximise interior space.

A number of aircraft accidents have involved outward-opening door failures, including:
 * American Airlines Flight 96 (1972) (design flaw)
 * Turkish Airlines Flight 981 (1974) (design flaw)
 * 1975 Tân Sơn Nhứt C-5 accident (poor maintenance)
 * United Airlines Flight 811 (1989) (design flaw)

title: Door


text:
Database normalization

Database normalization is the process of structuring a relational database in accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity. It was first proposed by British computer scientist Edgar F. Codd as part of his relational model.

Normalization entails organizing the columns (attributes) and tables (relations) of a database to ensure that their dependencies are properly enforced by database integrity constraints. It is accomplished by applying some formal rules either by a process of synthesis (creating a new database design) or decomposition (improving an existing database design).

Objectives
A basic objective of the first normal form defined by Codd in 1970 was to permit data to be queried and manipulated using a "universal data sub-language" grounded in first-order logic. An example of such a language is SQL, though it is one that Codd regarded as seriously flawed.

The objectives of normalization beyond 1NF (first normal form) were stated by Codd as:

When an attempt is made to modify (update, insert into, or delete from) a relation, the following undesirable side effects may arise in relations that have not been sufficiently normalized:

 * Insertion anomaly: There are circumstances in which certain facts cannot be recorded at all. For example, each record in a "Faculty and Their Courses" relation might contain a Faculty ID, Faculty Name, Faculty Hire Date, and Course Code. Therefore, the details of any faculty member who teaches at least one course can be recorded, but a newly hired faculty member who has not yet been assigned to teach any courses cannot be recorded, except by setting the Course Code to null.
 * Update anomaly: The same information can be expressed on multiple rows; therefore updates to the relation may result in logical inconsistencies. For example, each record in an "Employees' Skills" relation might contain an Employee ID, Employee Address, and Skill; thus a change of address for a particular employee may need to be applied to multiple records (one for each skill). If the update is only partially successful – the employee's address is updated on some records but not others – then the relation is left in an inconsistent state. Specifically, the relation provides conflicting answers to the question of what this particular employee's address is.
 * Deletion anomaly: Under certain circumstances, the deletion of data representing certain facts necessitates the deletion of data representing completely different facts. The "Faculty and Their Courses" relation described in the previous example suffers from this type of anomaly, for if a faculty member temporarily ceases to be assigned to any courses, the last of the records on which that faculty member appears must be deleted, effectively also deleting the faculty member, unless the Course Code field is set to null.

Minimize redesign when extending the database structure
A fully normalized database allows its structure to be extended to accommodate new types of data without changing existing structure too much. As a result, applications interacting with the database are minimally affected.

Normalized relations, and the relationship between one normalized relation and another, mirror real-world concepts and their interrelationships.

Normal forms
Codd introduced the concept of normalization and what is now known as the first normal form (1NF) in 1970. Codd went on to define the second normal form (2NF) and third normal form (3NF) in 1971, and Codd and Raymond F. Boyce defined the Boyce–Codd normal form (BCNF) in 1974.

Informally, a relational database relation is often described as "normalized" if it meets third normal form. Most 3NF relations are free of insertion, updation, and deletion anomalies.

The normal forms (from least normalized to most normalized) are:

• UNF: Unnormalized form

• 1NF: First normal form

• 2NF: Second normal form

• 3NF: Third normal form

• EKNF: Elementary key normal form

• BCNF: Boyce–Codd normal form

• 4NF: Fourth normal form

• ETNF: Essential tuple normal form

• 5NF: Fifth normal form

• DKNF: Domain-key normal form

• 6NF: Sixth normal form

Example of a step-by-step normalization
Normalization is a database design technique, which is used to design a relational database table up to higher normal form. The process is progressive, and a higher level of database normalization cannot be achieved unless the previous levels have been satisfied.

That means that, having data in unnormalized form (the least normalized) and aiming to achieve the highest level of normalization, the first step would be to ensure compliance to first normal form, the second step would be to ensure second normal form is satisfied, and so forth in order mentioned above, until the data conform to sixth normal form.

However, it is worth noting that normal forms beyond 4NF are mainly of academic interest, as the problems they exist to solve rarely appear in practice.

''The data in the following example were intentionally designed to contradict most of the normal forms. In practice it is often possible to skip some of the normalization steps because the data is already normalized to some extent. Fixing a violation of one normal form also often fixes a violation of a higher normal form. In the example, one table has been chosen for normalization at each step, meaning that at the end, some tables might not be sufficiently normalized.''

Initial data
Let a database table exist with the following structure:

For this example it is assumed that each book has only one author.

A table that conforms to the relational model has a primary key which uniquely identifies a row. In our example, the primary key is a composite key of {Title, Format} (indicated by the underlining):

{| class="wikitable" ! Title !Author !Author Nationality ! Format !Price !Subject !Pages !Thickness !Publisher !Publisher Country !Genre ID !Genre Name
 * Beginning MySQL Database Design and Optimization
 * Chad Russell
 * American
 * Hardcover
 * 49.99
 * 49.99

 * 520
 * Thick
 * Apress
 * USA
 * 1
 * Tutorial
 * }

Satisfying 1NF
In the first normal form each field contains a single value. A field may not contain a set of values or a nested record.

Subject contains a set of subject values, meaning it does not comply.

To solve the problem, the subjects are extracted into a separate Subject table:

Instead of one table in unnormalized form, there are now two tables conforming to the 1NF.

Satisfying 2NF
Recall that the Book table below has a composite key of {Title, Format}, which will not satisfy 2NF if some subset of that key is a determinant. At this point in our design the key is not finalised as the primary key, so it is called a candidate key. Consider the following table:

All of the attributes that are not part of the candidate key depend on Title, but only Price also depends on Format. To conform to 2NF and remove duplicates, every non-candidate-key attribute must depend on the whole candidate key, not just part of it.

To normalize this table, make {Title} a (simple) candidate key (the primary key) so that every non-candidate-key attribute depends on the whole candidate key, and remove Price into a separate table so that its dependency on Format can be preserved:

Now, both the Book and Price tables conform to 2NF.

Satisfying 3NF
The Book table still has a transitive functional dependency ({Author Nationality} is dependent on {Author}, which is dependent on {Title}). Similar violations exist for publisher ({Publisher Country} is dependent on {Publisher}, which is dependent on {Title}) and for genre ({Genre Name} is dependent on {Genre ID}, which is dependent on {Title}). Hence, the Book table is not in 3NF. To resolve this, we can place {Author Nationality}, {Publisher Country}, and {Genre Name} in their own respective tables, thereby eliminating the transitive functional dependencies:

Satisfying EKNF
The elementary key normal form (EKNF) falls strictly between 3NF and BCNF and is not much discussed in the literature. It is intended "to capture the salient qualities of both 3NF and BCNF" while avoiding the problems of both (namely, that 3NF is "too forgiving" and BCNF is "prone to computational complexity"). Since it is rarely mentioned in literature, it is not included in this example.

Satisfying 4NF
Assume the database is owned by a book retailer franchise that has several franchisees that own shops in different locations. And therefore the retailer decided to add a table that contains data about availability of the books at different locations:

As this table structure consists of a compound primary key, it doesn't contain any non-key attributes and it's already in BCNF (and therefore also satisfies all the previous normal forms). However, assuming that all available books are offered in each area, the Title is not unambiguously bound to a certain Location and therefore the table doesn't satisfy 4NF.

That means that, to satisfy the fourth normal form, this table needs to be decomposed as well:

Now, every record is unambiguously identified by a superkey, therefore 4NF is satisfied.

Satisfying ETNF
Suppose the franchisees can also order books from different suppliers. Let the relation also be subject to the following constraint:

 * If a certain supplier supplies a certain title
 * and the title is supplied to the franchisee
 * and the franchisee is being supplied by the supplier,
 * then the supplier supplies the title to the franchisee.

This table is in 4NF, but the Supplier ID is equal to the join of its projections:  {{Supplier ID, Title}, {Title, Franchisee ID}, {Franchisee ID, Supplier ID}} . No component of that join dependency is a superkey (the sole superkey being the entire heading), so the table does not satisfy the ETNF and can be further decomposed:

The decomposition produces ETNF compliance.

Satisfying 5NF
To spot a table not satisfying the 5NF, it is usually necessary to examine the data thoroughly. Suppose the table from 4NF example with a little modification in data and let's examine if it satisfies 5NF: Decomposing this table lowers redundancies, resulting in the following two tables: The query joining these tables would return the following data: The JOIN returns three more rows than it should; adding another table to clarify the relation results in three separate tables:

{|

 * }
 * }

What will the JOIN return now? It actually is not possible to join these three tables. That means it wasn't possible to decompose the Franchisee - Book - Location without data loss, therefore the table already satisfies 5NF.

C.J. Date has argued that only a database in 5NF is truly "normalized".

Satisfying DKNF
Let's have a look at the Book table from previous examples and see if it satisfies the domain-key normal form:

Logically, Thickness is determined by number of pages. That means it depends on Pages which is not a key. Let's set an example convention saying a book up to 350 pages is considered "slim" and a book over 350 pages is considered "thick".

This convention is technically a constraint but it is neither a domain constraint nor a key constraint; therefore we cannot rely on domain constraints and key constraints to keep the data integrity.

In other words – nothing prevents us from putting, for example, "Thick" for a book with only 50 pages – and this makes the table violate DKNF.

To solve this, a table holding enumeration that defines the Thickness is created, and that column is removed from the original table:

That way, the domain integrity violation has been eliminated, and the table is in DKNF.

Satisfying 6NF
A simple and intuitive definition of the sixth normal form is that "a table is in 6NF when the row contains the Primary Key, and at most one other attribute" .

That means, for example, the Publisher table designed while creating the 1NF:

needs to be further decomposed into two tables:

The obvious drawback of 6NF is the proliferation of tables required to represent the information on a single entity. If a table in 5NF has one primary key column and N attributes, representing the same information in 6NF will require N tables; multi-field updates to a single conceptual record will require updates to multiple tables; and inserts and deletes will similarly require operations across multiple tables. For this reason, in databases intended to serve online transaction processing (OLTP) needs, 6NF should not be used.

However, in data warehouses, which do not permit interactive updates and which are specialized for fast query on large data volumes, certain DBMSs use an internal 6NF representation – known as a columnar data store. In situations where the number of unique values of a column is far less than the number of rows in the table, column-oriented storage allow significant savings in space through data compression. Columnar storage also allows fast execution of range queries (e.g., show all records where a particular column is between X and Y, or less than X.)

In all these cases, however, the database designer does not have to perform 6NF normalization manually by creating separate tables. Some DBMSs that are specialized for warehousing, such as Sybase IQ, use columnar storage by default, but the designer still sees only a single multi-column table. Other DBMSs, such as Microsoft SQL Server 2012 and later, let you specify a "columnstore index" for a particular table.

title: Database normalization


text:
Desmothoracid

Order Desmothoracida, the desmothoracids, are a group of heliozoan protists, usually sessile and found in freshwater environments. The adult is a spherical cell around 10-20 μm in diameter surrounded by a perforated organic lorica, or shell, with many radial pseudopods projecting through the holes to capture food. These are supported by small bundles of microtubules that arise near a point on the nuclear membrane. Unlike other heliozoans, the microtubules are not in any regular geometric array, there does not appear to be a microtubule organizing center, and there is no distinction between the outer and inner cytoplasm.

Reproduction takes place by the budding-off of small motile cells, usually with two flagella. Later these are lost, and the pseudopods and lorica are formed. Typically, a single lengthened pseudopod will secrete a hollow stalk that attaches the cell to the substrate. The form of the flagella, the tubular cristae within the mitochondria, and other characters have led to the suggestion that the desmothoracids belong among what is now the Cercozoa. This was later confirmed by genetic studies.

As of the year 2000, the order Desmothoracida contained five genera with a total of 10 species.

 * Order Desmothoracida Hartwig & Lesser 1874 emend. Honigberg et al. 1964
 * Family Clathrulinidae Claus 1874
 * Genus Clathrulina Cienkowski 1867 [Podosphaera Archer 1868 non Kunze 1823 ; Elaster Grimm 1872 ; Eleaster (sic) Schmidt 1913 ; Orbulinella Entz 1877 ]
 * Species Clathrulina elegans Cienkowski 1867 [Clathrulina ovalis (von Daday 1885) Deflandre, 1926 ; Clathrulina cienkowskii ovalis von Daday 1885 ; Clathrulina cienkowskii Mereschkowsky 1879 ; Clathrulina stuhlmanni Schaudinn 1897 ; Podosphaera haeckeliana Archer 1868 ; Elaster greeffi Grimm 1872 ]
 * Species Clathrulina smaragdea (Entz 1877) Mikrjukov 2000 [Orbulinella smaragdea Entz 1877 ; Orbulinella salina Labbe 1924 ]
 * Genus Hedriocystis Hertwig & Lesser 1874
 * Species Hedriocystis pellucida Hertwig & Lesser 1874
 * Species Hedriocystis minor Siemensma 1991
 * Species Hedriocystis zhadani Mikrjukov 2000
 * Genus Penardiophrys Mikrjukov 2000
 * Species Penardiophrys reticulata (Penard 1904) Mikrjukov 2000 [Hedriocystis reticulata Penard 1904 ]
 * Species Penardiophrys spinifera (Brown 1918) Mikrjukov 2000 [Hedriocystis spinifera Brown 1918 ]
 * Genus Cienkowskya Schaudinn 1896 non Regel & Rach 1859 non Solms 1867 [Cienkowskia Weldon & Hickson 1909 non Rostafinski 1873 non Schweinfurth 1867 non Solms 1867 ; Wagneria Cienkowsky 1881 non Robineau-Desvoidy 1830 non Gistl 1848 non Alenitzin 1873 non Lemaire 1857 non Hesse 1912 non Heilprin 1887 non McCook 1895 non Jedlicka 1935 non Denier 1933 non Meladze 1967 ; Monomastigocystis de Saedeleer 1930]
 * Species Cienkowskya mereschkovckii (Cienkowsky 1881) Schaudinn 1896 [Wagneria mereschkowskyi Cienkowsky 1881 ]
 * Species Cienkowskya brachypous (De Saedeleer 1930) Mikrjukov 2000 [Monomastigocystis brachypous de Saedeleer 1930 ; Hedriocystis brachypous (De Saedeleer 1930) Siemensma 1991 ]
 * Genus Actinosphaeridium Zacharias 1893 [Actinopshaeridium (sic)]
 * Species Actinosphaeridium pedatus Zacharias 1893 [Nuclearia caulescens Penard 1903 ]

title: Desmothoracid