Early life and education.

Schirra was born on March 12, 1923, in Hackensack, New Jersey, to a family of aviators. His paternal grandparents were from Bavaria and Switzerland, and originally of Sardinian ancestry (more specifically from Ghilarza). Schirra's father, Walter M. Schirra Sr., who was born in Philadelphia, joined the Royal Canadian Air Force during World War I, and flew bombing and reconnaissance missions over Germany. After the war, he performed as a barnstormer at county fairs in New Jersey. Schirra's mother, Florence Shillito () Schirra, went along on her husband's barnstorming tours and performed wing walking stunts.  Schirra Jr. grew up in Oradell, New Jersey, where he attended elementary school and was a First Class Scout in Boy Scout Troop 36. He graduated from Dwight Morrow High School in Englewood, New Jersey in June 1940 and enrolled in the Newark College of Engineering (now New Jersey Institute of Technology, NJIT), where he was involved in the Reserve Officer Training Corps (ROTC) and the Sigma Pi fraternity. Following the attack on Pearl Harbor in December 1941, Schirra decided to apply to a service academy. His father encouraged him to apply to West Point, but he decided to enroll in the United States Naval Academy instead. Schirra graduated with a Bachelor of Science degree in 1945 after only three years instead of four, as the Naval Academy had a wartime accelerated curriculum.

Military service.

After graduating from the Naval Academy, Schirra was commissioned as an ensign in the United States Navy on June 6, 1945. Schirra served during the final months of World War II aboard the large cruiser. Following the Japanese surrender, Schirra returned to America, where the "Alaska" was decommissioned. He was subsequently stationed to Tsingtao and assigned to the amphibious command ship. Following his return from China, Schirra began training as a Naval Aviator at Naval Air Station Pensacola, Florida.  After he completed training, Schirra received his naval aviator wings in 1948 and joined Fighter Squadron 71 (VF-71) at Quonset Point, Rhode Island. In VF-71, Schirra flew the F8F Bearcat. After several years of flying the F8F, he attended jet transition training with the F-80 Shooting Star in preparation for his squadron's transition to the jet-powered F9F Panther. Schirra was deployed to the Mediterranean aboard the aircraft carrier at the outbreak of the Korean War in June 1950. He applied for an exchange program with the U.S. Air Force to gain combat experience, was selected for the program, and trained to fly on the F-84 Thunderjet.  Schirra was initially deployed with the 154th Fighter-Bomber Squadron to Itazuke Air Force Base in Japan, from where he flew missions into South Korea. As U.S. troops advanced north, the squadron was reassigned to a base in Daegu. In the eight-month deployment, Schirra flew 90 combat missions and downed two MiG-15s.  After completing his tour in Korea, Schirra became a test pilot at Naval Ordnance Test Station China Lake, California (NOTS). At China Lake, he tested various weapons systems, including becoming the first pilot to fly with and fire the Sidewinder missile. Schirra was assigned to Miramar Naval Air Station to test the newest Navy jet fighter, the F7U Cutlass. Schirra was subsequently assigned to NAS Moffett to begin transition training to the Cutlass, and subsequently the F3H Demon. After a deployment to Asia aboard the aircraft carrier and aviation safety training with the University of Southern California (USC), Schirra was accepted to the U.S. Naval Test Pilot School in 1958.  Schirra was a member of Class 20 at the Naval Test Pilot School, along with future fellow astronauts Jim Lovell and Pete Conrad, where he learned to fly numerous aircraft, including the F4D Skyray, the F11F Tiger, and the F8U Crusader. After graduation, Schirra became a test pilot at Naval Air Station Patuxent River and learned to fly the F4H Phantom to determine if it could become a carrier-based aircraft.

NASA career.

Project Mercury.

In February 1959, Schirra was one of 110 military test pilots selected by their commanding officers as candidates for the newly formed National Aeronautics and Space Administration's Project Mercury, the first U.S. crewed space flight program. Following several rounds of tests, Schirra became a member of the original seven astronauts selected for the program in April 1959. During the program's development, Schirra's areas of responsibility were the life-support systems and the pressurized flight suit. Additionally, Schirra worked alongside John Glenn in capsule design. Scott Carpenter and Schirra flew F-106 Delta Dart chase planes during Alan Shepard's "Freedom 7" suborbital mission. Schirra was initially assigned as Deke Slayton's backup for the second orbital Mercury flight but was replaced with Carpenter when Slayton was grounded. Schirra was instead scheduled for the third orbital flight.  At 7:15am on October 3, 1962, Schirra lifted off aboard his Mercury flight, named "Sigma 7". After a minor trajectory deviation early in flight, "Sigma 7" achieved orbit. Once in orbit, Schirra demonstrated manually positioning and maneuvering his spacecraft using a reaction control system. After the navigation issues during Carpenter's "Aurora 7" mission, NASA and Schirra focused on the engineering and human factors in manually operating the capsule. Schirra reported rising suit temperatures, reaching a high of, before he was able to adjust his suit's cooling system manually. After completing his spacecraft tests, Schirra tested his ability to use controls in a zero-gravity environment without sight. Throughout his mission, Schirra demonstrated the ability to act as a backup to automatic controls and manually fly the spacecraft. After six orbits, Schirra manually aligned his spacecraft over Africa and performed retrofire. "Sigma 7" landed from the recovery ship, the aircraft carrier, in the central Pacific Ocean. Once "Sigma 7" was on deck, Schirra activated the explosive hatch to egress the spacecraft, and received a large bruise, proving that Grissom had not intentionally opened his hatch on "Liberty Bell 7". After Schirra returned to the US, he and his family were invited to the Oval Office at the White House to meet President Kennedy on October 16.

Project Gemini.

At the beginning of the Gemini program, Alan Shepard was assigned to command Gemini 3 with Tom Stafford as the pilot, but they were replaced by a backup crew after Shepard was diagnosed with Ménière's disease, a disorder of the inner ear. Schirra and Stafford became the backup crew for the new Gemini 3 crew, Gus Grissom and John Young, and were subsequently scheduled for the Gemini 6 primary crew. Gemini 6 was originally scheduled to perform the first orbital docking with an Agena target vehicle. The Agena vehicle exploded shortly after takeoff on October 25, 1965, while Schirra and Stafford waited in their spacecraft to lift off. Program managers decided that rather than wait for a replacement Agena to be available, they would revise the mission, calling it Gemini 6A and having it attempt a rendezvous with Gemini 7, to be flown by Frank Borman and Jim Lovell. On December 4, 1965, Gemini 7 lifted off to begin its two-week mission. Gemini 6A prepared to launch on December 12, but its engines shut down less than two seconds after ignition. Despite protocols calling for the astronauts to eject from the spacecraft in the event of an engine shutdown, Schirra chose not to activate his and Stafford's rocket-powered ejection seats, saving them both from probable injuries and a further delay and possible cancellation of the mission. Gemini 6A lifted off on December 15 and successfully rendezvoused with Gemini 7 after five hours of flight. The two spacecraft maneuvered to within one foot of each other and kept station for 5 hours. Following the rendezvous, Gemini 6A deorbited on December 16 and was recovered in the Atlantic ocean southeast of Cape Canaveral by the.  While on the Gemini mission, Schirra played a Christmas practical joke on the flight controllers by first reporting a mock UFO (implying Santa Claus) sighting, then playing "Jingle Bells" on a four-hole Hohner harmonica he had smuggled on board, accompanied by Stafford on sleigh bells.

Apollo program.

In mid-1966, Schirra was assigned to command a three-man Apollo crew with Donn F. Eisele and R. Walter Cunningham to make the second crewed flight test of the Apollo Command/Service Module, with a mission profile identical to Apollo 1. Schirra argued against a repeat mission, and his crew became the backup crew for Gus Grissom, Ed White, and Roger Chaffee. Schirra's crew conducted tests in the command module on January 26, 1967, and were en route to Houston the next day when Grissom and his crew were killed in a fire during a test. Schirra's crew became the prime crew of the first crewed flight. This became Apollo 7 in the program's revised mission numbering plan, and was delayed until the fall of 1968 while safety improvements were made to the Command Module.  Schirra had gained a sense of security from having Guenter Wendt, a McDonnell Aircraft employee, as the pad leader responsible for the spacecraft's launch readiness. As the Apollo contractor was now North American Aviation, Wendt was no longer pad leader. After the Apollo 1 accident, Schirra felt so strongly he wanted none other than Wendt as pad leader for his Apollo flight, that he convinced Deke Slayton and North American's launch operations manager Bastian "Buzz" Hello to hire Wendt as Apollo 7 pad leader. Wendt remained pad leader for the remainder of the Apollo and Skylab programs, and stayed on with NASA into the Space Shuttle program before retiring.  Apollo 7 was launched on October 11, 1968, making Schirra the first person to fly in space three times. Prior to launch, Schirra had objected because of high winds, which could have injured the astronauts in the event of an abort within the first minute of the mission. After reaching orbit, the Apollo 7 CSM performed space rendezvous and docking exercises with the S-4B stage to simulate retrieving the Apollo Lunar Module. On the second day of the mission, the crew conducted the first live television pictures publicly broadcast from inside a crewed spacecraft.  During the mission, Schirra became sick with a head cold, which he passed to Eisele. Anticipating issues with congestion inside of a sealed spacesuit, Schirra proposed to Mission Control that they would not wear their helmets during reentry. Despite a request from Chris Kraft and Deke Slayton to wear helmets during reentry, Schirra, Eisele, and Cunningham refused and performed reentry without them. Apollo 7 landed southeast of Bermuda on October 22, 1968.  Prior to the Apollo 7 launch, Schirra had made the decision to retire after the flight, and left the NASA Astronaut Corps on July 1, 1969. Schirra's last assignment as an astronaut was to conduct the investigation into Neil Armstrong's Lunar Landing Research Vehicle crash, which he attributed to a mechanical failure and recommended suspending training with the vehicle. On the same date, Schirra retired from the Navy with the rank of Captain.

Post-NASA career.

Television career.

A combination of pseudoephedrine decongestant with triprolidine antihistamine was the cold medicine carried on board the Apollo missions and prescribed by the flight surgeon. Years later when this became available over the counter as Actifed, the makers of Actifed hired Schirra as a television commercial spokesman, based on the notoriety of his Apollo 7 in-space head cold.  During later Apollo missions, he served as a consultant to CBS News from 1969 to 1975. He joined Walter Cronkite to co-anchor the network's coverage of the seven Moon landing missions, starting with Apollo 11 (joined by Arthur C. Clarke) and including the ill-fated Apollo 13.

Business career.

Following his NASA career, Schirra became president and a director of the financial and leasing company Regency Investors Incorporated. He left Regency Investors to form Environmental Control Company and served as the company's chairman and CEO from 1970 to 1973. The company merged with SERNCO Incorporated in 1973. Schirra started as vice-chairman, but was elected to chairman of the board later that year. He also worked to develop an Alaskan oil pipeline and was a member of an advisory board for U.S. National Parks in the Department of the Interior from 1973 to 1985.  In January 1979, Schirra founded Schirra Enterprises, and worked as a consultant until 1980. He worked for the Belgian Consulate for Colorado and New Mexico, from 1971 to 1984, and was a board member of several corporations including Electromedics, Finalco, Kimberly-Clark, Net Air International, Rocky Mountain Airlines, and Johns-Manville Corporation. Schirra was president of the energy development company Prometheus from 1980 to 1981. In 1984, he was among the surviving Mercury astronauts who established the Mercury Seven Foundation, now known as the Astronaut Scholarship Foundation, to award college scholarships to science and engineering students.

Writing career.

Schirra, along with the rest of the Mercury Seven, co-authored the 1962 book "We Seven," detailing the training and development of the Mercury program. Along with Richard N. Billings, Schirra released his autobiography "Schirra's Space" in 1988. In 1995, he co-authored the book "Wildcats to Tomcats: The Tailhook Navy" with Barrett Tillman and fellow Navy Captains Richard L. (Zeke) Cormier, and Phil Wood. It describes five decades of Naval aviation, including accounts of combat tours in World War II, Korea, and Vietnam. In 2005, he co-authored the book "The Real Space Cowboys" with Ed Buckbee. The book is an account of the 'Mercury Seven' astronauts. It follows them through the process of selection for the program, their entire careers, and into retirement. Schirra was also a contributor to the 2007 book, "In the Shadow of the Moon", which was his final authored work.

Personal life.

Shortly after being commissioned in the Navy, Schirra began dating Josephine Cook "Jo" Fraser (1924–2015). Schirra and Fraser were married on February 23, 1946. They had two children, Walter M. (III) and Suzanne, born in 1950 and 1957. Jo Schirra died April 27, 2015, at the age of 91.

Death.

Schirra died on May 3, 2007, of a heart attack while undergoing treatment for abdominal cancer at Scripps Green Hospital (currently The Heart Center at Scripps) in San Diego, California. He was 84 years old. A memorial service for Schirra was held on May 22 at Fort Rosecrans National Cemetery in California. The ceremony concluded with a three-volley salute and a flyover by three F/A-18s. Schirra was cremated and his ashes were committed to the sea on February 11, 2008. The burial at sea ceremony was held aboard the and his ashes were released by Commander Lee Axtell, CHC, USN, the command chaplain aboard.

Awards and honors.

Throughout his military career, Schirra received numerous military decorations, including three Air Medals and three NASA Distinguished Service Medals, including one posthumously. His first NASA Distinguished Service Medal was for his Mercury flight, and the second for his Gemini 6 flight. He was also awarded the NASA Exceptional Service Medal, the American Campaign Medal, the Asiatic-Pacific Campaign Medal, the World War II Victory Medal, the Navy Occupation Medal with "ASIA" clasp, the China Service Medal, and the Korean Service Medal. Additionally, he received several international awards, including a Korean Presidential Unit Citation, the United Nations Korea Medal, and the Korean War Service Medal. Schirra has also received civilian aviation awards, the AIAA Award (1963), the Harmon Trophy (1965), the Kitty Hawk Award, and the Golden Key Award.  When Schirra was awarded his Navy Astronaut Wings by Secretary Fred Korth, the Navy's uniform guidance did not specify if it would be worn alongside his naval aviator wings, or replace them. Schirra decided to wear his astronaut wings above his ribbons, and the aviator wings below them. Schirra was awarded the Navy Distinguished Service Medal for being the commander of Apollo 7. He was also awarded a Distinguished Flying Cross for escorting B-29 bombers during the Korean War, a gold star for his "Sigma 7" flight, and a second gold star for flying on Gemini 6. Schirra, a fellow of Society of Experimental Test Pilots (SETP), received the Iven C. Kincheloe Award from the society in 1963, along with the other six Mercury astronauts. He was awarded the Robert J. Collier Trophy in 1962, along with the rest of the Mercury 7. The award was typically given to engineers and inventors, but aviators were awarded this time instead.  Schirra was a 33rd Degree Mason and part of the American Institute of Aeronautics and Astronautics, as well as a fellow of the American Astronautical Society. Schirra received Honorary Doctorates of Science from three colleges and universities: Lafayette College (for Astronautical Engineering), the University of Southern California, and his alma mater the Newark College of Engineering (for Astronautics). Schirra was inducted into multiple halls of fame: the International Air & Space Hall of Fame (1970), the International Space Hall of Fame (1981), the National Aviation Hall of Fame (1986), the U.S. Astronaut Hall of Fame (1990), and the New Jersey Hall of Fame. The, a named for Schirra, was christened and launched March 8, 2009. A street and a park are named after Schirra in Upper Dublin, Pennsylvania, and Oradell, New Jersey. Walter M. Schirra Elementary School in Old Bridge Township, New Jersey, is named after Schirra.

Walter Marty Schirra Jr. (, March 12, 1923 – May 3, 2007), (Captain, USN, Ret.), was an American naval aviator, test pilot, and NASA astronaut. In 1959, he became one of the original seven astronauts chosen for Project Mercury, which was the United States' first effort to put human beings into space. On October 3, 1962, he flew the six-orbit, nine-hour, Mercury-Atlas 8 mission, in a spacecraft he nicknamed "Sigma 7". At the time of his mission in "Sigma 7", Schirra became the fifth American and ninth human to travel into space. In the two-man Gemini program, he achieved the first space rendezvous, station-keeping his Gemini 6A spacecraft within of the sister Gemini 7 spacecraft in December 1965. In October 1968, he commanded Apollo 7, an 11-day low Earth orbit shakedown test of the three-man Apollo Command/Service Module and the first crewed launch for the Apollo program.

Walter Marty Schirra, Jr. (12. března 1923 Hackensack, New Jersey, USA – 3. května 2007 La Jolla, Kalifornie, USA) byl americký zkušební pilot a astronaut, jeden z původní sedmičky astronautů vybraných v rámci prvního amerického pilotovaného kosmického programu Mercury. Byl jediným Američanem, který absolvoval lety v kosmických lodích programů Mercury, Gemini a Apollo. Během tří letů strávil 295 hodin a 15 minut na oběžné dráze Země.


History.

In the Roman era, a fortified tower guarded the crossing of two Roman roads that met at the site of Luxembourg city. Through an exchange treaty with the abbey of Saint Maximin in Trier in 963, Siegfried I of the Ardennes, a close relative of King Louis II of France and Emperor Otto the Great, acquired the feudal lands of Luxembourg. Siegfried built his castle, named "Lucilinburhuc" ("small castle"), on the Bock "Fiels" ("rock"), mentioned for the first time in the aforementioned exchange treaty.  In 987, Archbishop Egbert of Trier consecrated five altars in the Church of the Redemption (today St. Michael's Church). At a Roman road intersection near the church, a marketplace appeared around which the city developed.  The city, because of its location and natural geography, has through history been a place of strategic military significance. The first fortifications were built as early as the 10th century. By the end of the 12th century, as the city expanded westward around the new St. Nicholas Church (today the Cathedral of Notre Dame), new walls were built that included an area of. In about 1340, under the reign of John the Blind, new fortifications were built that stood until 1867.  In 1443, the Burgundians under Philip the Good conquered Luxembourg. Luxembourg became part of the Burgundian, and later Spanish and Austrian empires (See Spanish Netherlands and Spanish Road) and under those Habsburg administrations Luxembourg Castle was repeatedly strengthened so that by the 16th century, Luxembourg itself was one of the strongest fortifications in Europe. Subsequently, the Burgundians, the Spanish, the French, the Spanish again, the Austrians, the French again, and the Prussians conquered Luxembourg.  In the 17th century, the first casemates were built; initially, Spain built of tunnels, starting in 1644. These were then enlarged under French rule by Marshal Vauban, and augmented again under Austrian rule in the 1730s and 1740s.  During the French Revolutionary Wars, the city was occupied by France twice: once, briefly, in 1792–3, and, later, after a seven-month siege. Luxembourg held out for so long under the French siege that French politician and military engineer Lazare Carnot called Luxembourg "the best fortress in the world, except Gibraltar", giving rise to the city's nickname: the 'Gibraltar of the North'.  Nonetheless, the Austrian garrison eventually surrendered, and as a consequence, Luxembourg was annexed by the French Republic, becoming part of the département of Forêts, with Luxembourg City as its préfecture. Under the 1815 Treaty of Paris, which ended the Napoleonic Wars, Luxembourg City was placed under Prussian military control as a part of the German Confederation, although sovereignty passed to the House of Orange-Nassau, in personal union with the United Kingdom of the Netherlands.  After the Luxembourg Crisis, the 1867 Treaty of London required Luxembourg to dismantle the fortifications in Luxembourg City. Their demolition took sixteen years, cost 1.5 million gold francs, and required the destruction of over of underground defences and of casemates, batteries, barracks, etc. Furthermore, the Prussian garrison was to be withdrawn. When, in 1890, Grand Duke William III died without any male heirs, the Grand Duchy passed out of Dutch hands, and into an independent line under Grand Duke Adolphe. Thus, Luxembourg, which had hitherto been independent in theory only, became a truly independent country, and Luxembourg City regained some of the importance that it had lost in 1867 by becoming the capital of a fully independent state.  Despite Luxembourg's best efforts to remain neutral in the First World War, it was occupied by Germany on 2 August 1914. On 30 August, Helmuth von Moltke moved his headquarters to Luxembourg City, closer to his armies in France in preparation for a swift victory. However, the victory never came, and Luxembourg would play host to the German high command for another four years. At the end of the occupation, Luxembourg City was the scene of an attempted communist revolution; on 9 November 1918, communists declared a socialist republic, but it lasted only a few hours.  In 1921, the city limits were greatly expanded. The communes of Eich, Hamm, Hollerich, and Rollingergrund were incorporated into Luxembourg City, making the city the largest commune in the country (a position that it would hold until 1978).  In 1940, Germany occupied Luxembourg again. The Nazis were not prepared to allow Luxembourgers self-government, and gradually integrated Luxembourg into the Third Reich by informally attaching the country administratively to a neighbouring German province. Under the occupation, the capital city's streets all received new, German names, which was announced on 4 October 1940. The Avenue de la Liberté for example, a major road leading to the railway station, was renamed "Adolf-Hitlerstraße". Luxembourg City was liberated on 10 September 1944. The city was under long-range bombardment by the German V-3 cannon in December 1944 and January 1945.  After the war, Luxembourg ended its neutrality, and became a founding member of several inter-governmental and supra-governmental institutions. In 1952, the city became the headquarters of the High Authority of the European Coal and Steel Community. In 1967, the High Authority was merged with the commissions of the other European institutions; although Luxembourg City was no longer the seat of the ECSC, it hosted some part-sessions of the European Parliament until 1981. Luxembourg remains the seat of the European Parliament's secretariat, as well as the Court of Justice of the European Union, the European Court of Auditors, and the European Investment Bank. Several departments of the European Commission are also based in Luxembourg.

Geography.

The highest point of the Grand-Duchy of Luxembourg is Kneiff at 560 m, closely followed by Burgplatz at 559 m and Napoleonsgaart at 554 m.

Topography.

Luxembourg City lies on the southern part of the Luxembourg plateau, a large Early Jurassic sandstone formation that forms the heart of the Gutland, a low-lying and flat area that covers the southern two-thirds of the country.  The city centre occupies a picturesque site on a salient, perched high on precipitous cliffs that drop into the narrow valleys of the Alzette and Pétrusse rivers, whose confluence is in Luxembourg City. The deep gorges cut by the rivers are spanned by many bridges and viaducts, including the Adolphe Bridge, the Grand Duchess Charlotte Bridge, and the Passerelle. Although Luxembourg City is not particularly large, its layout is complex, as the city is set on several levels, straddling hills and dropping into the two gorges.  The commune of Luxembourg City covers an area of over, or 2% of the Grand Duchy's total area. This makes the city the fourth-largest commune in Luxembourg, and by far the largest urban area. Luxembourg City is not particularly densely populated, at about 1,700 people per km; large areas of Luxembourg City are maintained as parks, forested areas, or sites of important heritage (particularly the UNESCO sites), while there are also large tracts of farmland within the city limits.

Quarters of Luxembourg City.

Luxembourg City is subdivided into twenty-four quarters (), which cover the commune in its entirety. The quarters generally correspond to the major neighbourhoods and suburbs of Luxembourg City, although a few of the historic districts, such as Bonnevoie, are divided between two quarters.

Climate.

Considering its latitude, Luxembourg City has an oceanic climate, with moderate precipitation, cold to cool winters and warm summers. Moderate to heavy cloud cover is present for more than two-thirds of the year.

Government.

Local government.

Under the Luxembourgian constitution, local government is centred on the city's communal council. Consisting of twenty-seven members (fixed since 1964), each elected every six years on the second Sunday of October and taking office on 1 January of the next year, the council is the largest of all communal councils in Luxembourg. The city is nowadays considered a stronghold of the Democratic Party (DP), which is the second-largest party nationally. Currently, the Democratic Party is the largest party on the council, with eleven councillors.  The city's administration is headed by the mayor, who is the leader of the largest party on the communal council. After Xavier Bettel became Luxembourg's new prime minister on 4 December 2013, Lydie Polfer (DP) was sworn in as new mayor of Luxembourg on 17 December of the same year. The mayor leads the cabinet, the "collège échevinal", in which the DP forms a coalition with The Greens. Unlike other cities in Luxembourg, which are limited to four "échevins" at most, Luxembourg is given special dispensation to have six "échevins" on its "collège échevinal".

National government.

Luxembourg City is the seat for the Luxembourg Government. The Grand Ducal Family of Luxembourg lives at Berg Castle in Colmar-Berg.  For national elections to the Chamber of Deputies, the city is located in the Centre constituency.

European institutions.

Luxembourg City is the seat of several institutions, agencies and bodies of the European Union, including the Court of Justice of the European Union, the European Commission, the secretariat of the European Parliament, the European Court of Auditors and the European Investment Bank. The majority of these institutions are located in the Kirchberg quarter, in the northeast of the city.

Culture.

Despite the city's comparatively small size, it has several notable museums: the recently renovated National Museum of History and Art (MNHA), the Luxembourg City History Museum, the new Grand Duke Jean Museum of Modern Art (Mudam) and National Museum of Natural History (NMHN). The city of Luxembourg itself is on the UNESCO World Heritage List, on account of the historical importance of its fortifications. In addition to its two main theatres, the Grand Théâtre de Luxembourg and the Théâtre des Capucins, there is a new concert hall, the Philharmonie, as well as a conservatory with a large auditorium. Art galleries include the Villa Vauban, the Casino Luxembourg and Am Tunnel.  Luxembourg was the first city to be named European Capital of Culture twice. The first time was in 1995. In 2007, along with the Romanian city of Sibiu, the European Capital of Culture was to be a cross-border area consisting of the Grand Duchy of Luxembourg, the Rheinland-Pfalz and Saarland in Germany, the Walloon Region and the German-speaking part of Belgium, and the Lorraine area in France. The event was an attempt to promote mobility and the exchange of ideas, crossing borders in all areas, physical, psychological, artistic and emotional.  Luxembourg City is also famed for its wide selection of restaurants and cuisines, including four Michelin starred establishments.

Sport.

The ING Europe Marathon has been contested annually in the capital since June 2006. It attracted 11,000 runners and over 100,000 spectators during the 2014 edition  The Luxembourg Open is a tennis tournament held since 1991 in the capital. The tournament runs from 13 to 21 October. BGL BNP Paribas, one of the more famous sponsors in the world of tennis, is the contracted title sponsor of the tournament until 2014.  The D'Coque National Sporting and Cultural Centre, in the quarter of Kirchberg, is the largest sporting venue in the country, with a capacity of 8,300 for indoor sports and swimming.  The two football clubs of the city of Luxembourg; Racing FC Union Luxembourg and FC RM Hamm Benfica, play in the country's highest league, the Luxembourg National Division. The 8,000-seater Stade Josy Barthel hosts the Luxembourg national football team, and CAL Spora Luxembourg, which with 400 members is the nation's largest athletics club.

Places of interest.

Places of interest include the Gothic Revival Cathedral of Notre Dame, the fortifications, the AM Tunnel (an art gallery underground), the Grand Ducal Palace, the Gëlle Fra war memorial, the casemates, the Neumünster Abbey, the Place d'Armes, the Adolphe Bridge and the city hall. The city is the home of the University of Luxembourg and RTL Group.  The Second World War Luxembourg American Cemetery and Memorial is located within the city limits of Luxembourg at Hamm. This cemetery is the final resting place of 5,076 American military dead, including General George S. Patton. There is also a memorial to 371 Americans whose remains were never recovered or identified.

Transport.

Highways.

Luxembourg is situated in the heart of Europe in the Gold Triangle between Frankfurt, Paris, and Amsterdam. It is therefore connected to several motorways and international routes.

Public transport.

Rail.

Luxembourg City is served by five rail stations operated by the state rail company, the Société Nationale des Chemins de Fer Luxembourgeois (CFL), including the principal station and terminus of all rail lines in the Grand Duchy, Luxembourg station. Stations in Luxembourg City are served by domestic rail services operated by CFL, as well as international rail services, operated by CFL, and German, Belgian, and French service providers. Additionally, Luxembourg station is connected to the French LGV Est network, providing high-speed services on to Paris and Strasbourg. Services to Basel and Zürich in Switzerland are available via two daily scheduled international trains.

Bus.

Luxembourg City has a network of 31 bus routes, operated by the municipal transport authority, "Autobus de la Ville de Luxembourg" (AVL), partly subcontracted to private bus companies. There is also a free bus service linking the Glacis to Luxembourg station, the "Joker Line" for seniors, and a "City night network". A "Park & Ride" scheme is operated by the city with five carparks connected to the bus network. In addition to AVL buses, CFL and RGTR operate regional buses to other locales in Luxembourg and nearby cities in Germany and France.

Tram.

On 10 December 2017, the first stage of Luxembourg City's new tram line opened between Luxexpo and the Grand Duchess Charlotte Bridge serving the Kirchberg quarter. An extension to the city centre ("Stäreplaz-Étoile") was opened on 27 July 2018. Further extensions to Luxembourg station, Bonnevoie, Howald, and Cloche d’Or are due to be completed by 2020/21.

Air.

Luxembourg City is served by the only international airport in the country: Luxembourg Airport (codes: IATA: LUX, ICAO: ELLX). Accessibility to the airport, situated in the commune of Sandweiler, from the city centre, is provided via the municipal bus network, with a tram connection due to be completed by 2021. The airport is the principal hub for Luxembourg's flag carrier, Luxair, and one of the world's largest cargo airlines, Cargolux.

International relations.

Luxembourg is a member of the QuattroPole union of cities, along with Trier, Saarbrücken, and Metz (neighbouring countries: Germany and France).

Twin towns – Sister cities.

Luxembourg is twinned with:

Luxembourg (,, ), also known as Luxembourg City ( or "",, ), is the capital city of the Grand Duchy of Luxembourg and the country's most populous commune. Standing at the confluence of the Alzette and Pétrusse rivers in southern Luxembourg, the city lies at the heart of Western Europe, situated by road from Brussels, from Paris, and from Cologne. The city contains Luxembourg Castle, established by the Franks in the Early Middle Ages, around which a settlement developed.

Lucemburk (,, ) je hlavní město Lucemburského velkovévodství a má 115 227 obyvatel (2016). Leží na skalnatém masívu nad soutokem řek Alzette a Pétrusse a je významným bankovním a administrativním centrem. Složitý členitý terén je překonáván pomocí 100 mostů, které patří pro své nádherné pohledy na město mezi časté turistické cíle. Historické centrum města figuruje od roku 1994 na seznamu světového kulturního dědictví UNESCO.


Structure.

Xenon difluoride is a linear molecule with an Xe–F bond length of in the vapor stage, and 200 pm in the solid phase. The packing arrangement in solid shows that the fluorine atoms of neighbouring molecules avoid the equatorial region of each molecule. This agrees with the prediction of VSEPR theory, which predicts that there are 3 pairs of non-bonding electrons around the equatorial region of the xenon atom.  At high pressures, novel, non-molecular forms of xenon difluoride can be obtained. Under a pressure of ~50 GPa, transforms into a semiconductor consisting of units linked in a two-dimensional structure, like graphite. At even higher pressures, above 70 GPa, it becomes metallic, forming a three-dimensional structure containing units. However, a recent theoretical study has cast doubt on these experimental results.  The Xe–F bonds are weak. XeF has a total bond energy of, with first and second bond energies of and, respectively. However, XeF is much more robust than KrF, which has a total bond energy of only.

Chemistry.

Synthesis.

Synthesis proceeds by the simple reaction:  The reaction needs heat, irradiation, or an electrical discharge. The product is a solid. It is purified by fractional distillation or selective condensation using a vacuum line.  The first published report of XeF was in October 1962 by Chernick, et al. However, though published later, XeF was probably first created by Rudolf Hoppe at the University of Münster, Germany, in early 1962, by reacting fluorine and xenon gas mixtures in an electrical discharge. Shortly after these reports, Weeks, Cherwick, and Matheson of Argonne National Laboratory reported the synthesis of XeF using an all-nickel system with transparent alumina windows, in which equal parts xenon and fluorine gases react at low pressure upon irradiation by an ultraviolet source to give XeF. Williamson reported that the reaction works equally well at atmospheric pressure in a dry Pyrex glass bulb using sunlight as a source. It was noted that the synthesis worked even on cloudy days.  In the previous syntheses the fluorine gas reactant had been purified to remove hydrogen fluoride. Šmalc and Lutar found that if this step is skipped the reaction rate proceeds at four times the original rate.  In 1965, it was also synthesized by reacting xenon gas with dioxygen difluoride.

Solubility.

is soluble in solvents such as,,, anhydrous hydrogen fluoride, and acetonitrile, without reduction or oxidation. Solubility in hydrogen fluoride is high, at 167 g per 100 g HF at 29.95 °C.

Derived xenon compounds.

Other xenon compounds may be derived from xenon difluoride. The unstable organoxenon compound can be made by irradiating hexafluoroethane to generate radicals and passing the gas over. The resulting waxy white solid decomposes completely within 4 hours at room temperature.  The XeF cation is formed by combining xenon difluoride with a strong fluoride acceptor, such as an excess of liquid antimony pentafluoride ():  Adding xenon gas to this pale yellow solution at a pressure of 2–3 atmospheres produces a green solution containing the paramagnetic ion, which contains a Xe−Xe bond: ("apf" denotes solution in liquid )  This reaction is reversible; removing xenon gas from the solution causes the ion to revert to xenon gas and, and the color of the solution returns to a pale yellow.  In the presence of liquid HF, dark green crystals can be precipitated from the green solution at −30 °C:  X-ray crystallography indicates that the Xe–Xe bond length in this compound is 309 pm, indicating a very weak bond. The ion is isoelectronic with the ion, which is also dark green.

Coordination chemistry.

Bonding in the XeF molecule is adequately described by the three-center four-electron bond model.  XeF can act as a ligand in coordination complexes of metals. For example, in HF solution:  Crystallographic analysis shows that the magnesium atom is coordinated to 6 fluorine atoms. Four of the fluorines are attributed to the four xenon difluoride ligands while the other two are a pair of "cis"- ligands.  A similar reaction is:  In the crystal structure of this product the magnesium atom is octahedrally-coordinated and the XeF ligands are axial while the ligands are equatorial.  Many such reactions with products of the form [M(XeF)](AF) have been observed, where M can be calcium, strontium, barium, lead, silver, lanthanum, or neodymium and A can be arsenic, antimony or phosphorus.  Recently, a compound was synthesised where a metal atom was coordinated solely by XeF fluorine atoms:  This reaction requires a large excess of xenon difluoride. The structure of the salt is such that half of the Ca ions are coordinated by fluorine atoms from xenon difluoride, while the other Ca ions are coordinated by both XeF and.

Applications.

As a fluorinating agent.

Xenon difluoride is a strong fluorinating and oxidizing agent. With fluoride ion acceptors, it forms and species which are even more powerful fluorinators.  Among the fluorination reactions that xenon difluoride undergoes are:  XeF can similarly be used to prepare "N"-fluoroammonium salts, useful as fluorine transfer reagents in organic synthesis (e.g., Selectfluor), from the corresponding tertiary amine:  Silicon tetrafluoride has been found to act as a catalyst in fluorination by.

As an etchant.

Xenon difluoride is also used as an isotropic gaseous etchant for silicon, particularly in the production of microelectromechanical systems (MEMS), as first demonstrated in 1995. Commercial systems use pulse etching with an expansion chamber Brazzle, Dokmeci, et al. describe this process:  The mechanism of the etch is as follows. First, the XeF adsorbs and dissociates to xenon and fluorine atoms on the surface of silicon. Fluorine is the main etchant in the silicon etching process. The reaction describing the silicon with XeF is XeF has a relatively high etch rate and does not require ion bombardment or external energy sources in order to etch silicon.

Xenon difluoride is a powerful fluorinating agent with the chemical formula, and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture-sensitive. It decomposes on contact with light or water vapor but is otherwise stable in storage. Xenon difluoride is a dense, white crystalline solid.

Fluorid xenonatý (též xenon difluorid) je bílá krystalická látka, zápachem připomínající ozón, která se skládá z paralelních lineárních tříatomových molekul XeF. Lze jej připravit přímou syntézou z prvků, reakcí xenonu s nadbytkem fluoru v zatavené niklové nádobě nebo ozařováním této směsi slunečním světlem:


Life and career.

Vinterberg was born in Frederiksberg, Denmark. In 1993, he graduated from the National Film School of Denmark with "Last Round" ("Sidste Omgang"), which won the jury and producers' awards at the Munich International Festival of Film Schools, and First Prize at Tel Aviv. That year Vinterberg made his first TV drama for DR TV and his short fiction film "The Boy Who Walked Backwards", produced by Birgitte Hald at Nimbus Film.  This film has won awards and accolades all over the world, including Nordic Panorama in Iceland, the International Short Film Festival in Clermont-Ferrand, and the Toronto International Film Festival.  His first feature film was "The Biggest Heroes" ("De Største Helte"), a road movie that received acclaim in his native Denmark.  In 1995, Vinterberg formed the Dogme 95 movement with Lars von Trier, Kristian Levring, and Søren Kragh-Jacobsen.  Following that dogma in 1998, he conceived, wrote and directed (and also had a small acting role in) the first of the Dogme movies, "The Celebration" ("Festen"). As per the rules of the Dogme manifesto, he did not take a directorial credit. However, he and the film won numerous nominations and awards, including the Jury Prize at the 1998 Cannes Film Festival.  In 2003 he directed the apocalyptic science fiction love story "It's All About Love", a movie he wrote, directed and produced himself over a period of five years. This movie was entirely in English and featured, among others, Joaquin Phoenix, Claire Danes, and Sean Penn. The movie did not do well, as critics and audiences found it idiosyncratic and somewhat incomprehensible.  His next film, the English-language "Dear Wendy" (2005), scripted by Lars von Trier, also flopped, even in his native Denmark where it sold only 14,521 tickets. However he won the Silver George for Best Director at the 27th Moscow International Film Festival. Vinterberg then tried to retrace his roots with a smaller Danish-language production, "En mand kommer hjem" (2007), which also flopped, selling only 31,232 tickets.  On 1 August 2008. he directed the music video for "The Day That Never Comes", the first single off Metallica's album "Death Magnetic".  His 2010 film "Submarino" was nominated for the Golden Bear at the 60th Berlin International Film Festival.  In 2012, his film "The Hunt" competed for the Palme d'Or at the 2012 Cannes Film Festival and was shortlisted for the Best Foreign Language Film award at the 86th Academy Awards.  In 2015, he directed "Far from the Madding Crowd", an adaptation of the acclaimed Thomas Hardy novel, starring Carey Mulligan, Matthias Schoenaerts, Michael Sheen and Tom Sturridge.  Vinterberg reunited with Matthias Schoenaerts in "Kursk", a film about the Kursk submarine disaster that happened in 2000.

Honours.

In April 2016, the French government appointed Vinterberg a "Chevalier" (Knight) of the Ordre des Arts et des Lettres.

Thomas Vinterberg (; born 19 May 1969) is a Danish film director who, along with Lars von Trier, co-founded the Dogme 95 movement in filmmaking, which established rules for simplifying movie production. He is best known for the films "The Celebration" (1998), "Submarino" (2010), "The Hunt" (2012) and "Far from the Madding Crowd" (2015).

Thomas Vinterberg (* 19. května 1969 Kodaň) je dánský filmový režisér, známý jako spoluzakladatel hnutí Dogme 95, prosazujícího oproštění filmu od nadbytečných efektů.


Operation.

A railroad car's wheels are guided along the tracks by coning of the wheels. Only in extreme cases does it rely on the flanges located on the insides of the wheels. When the wheels reach the switch, the wheels are guided along the route determined by which of the two points is connected to the track facing the switch. In the illustration, if the left point is connected, the left wheel will be guided along the rail of that point, and the train will diverge to the right. If the right point is connected, the right wheel's flange will be guided along the rail of that point, and the train will continue along the straight track. Only one of the points may be connected to the facing track at any time; the two points are mechanically locked together to ensure that this is always the case.  A mechanism is provided to move the points from one position to the other ("change the points"). Historically, this would require a lever to be moved by a human operator, and some switches are still controlled this way. However, most are now operated by a remotely controlled electric motor or by pneumatic or hydraulic actuation, called a point machine. This both allows for remote control and for stiffer, strong switches that would be too difficult to move by hand, yet allow for higher speeds.  In a trailing-point movement (running through the switch in the wrong direction while they are set to turn off the track), the flanges on the wheels will force the points to the proper position. This is sometimes known as "running through the switch". Some switches are designed to be forced to the proper position without damage. Examples include variable switches, spring switches, and weighted switches.  If a switch becomes worn or the operating rods become damaged, it is possible for the flange to "split the switch", and go through the switch in the direction other than what was expected. This happens when the flange strikes a small gap between the fixed rail and the set switch point (whichever is touching the main line); this forces the switch open, and the train is diverted down the incorrect track. This can either happen to the locomotive, in which case the whole train can be directed onto the wrong track, with potentially dangerous results, or it can occur at any point through the train, when a random truck is directed down a different track from the rest of the train; if this happens on the front truck of a car, the usual result is derailment, as the trailing truck of the preceding car attempts to go one way, while the leading truck of the following car tries to go another. If it happens to the trailing truck of a car, the front truck will follow one track, while the trailing truck follows a parallel line; this causes the whole car to "crab", or move sideways down the track (derailment often results eventually, due to the lateral forces applied when the train tries to brake or accelerate). This can have disastrous results if there is any obstacle between the lines, as the car will be propelled into it sideways, such as happened in the 1928 Times Square derailment. In some cases, the whole train behind the car will follow the errant car onto the other track; in others, only one or a few trucks are diverted, while the rest follow the correct track. In cases where it is a simple siding, rather than a continuous parallel track, the diverted truck(s) can travel the whole length of the siding until it turns back to the main track, where it performs a "trailing point movement", forces the switch open, and ends up back on the same track again, with only damage to the switches. This is far less likely in cases of diversion to a parallel track, since switches on both lines will often be interconnected, so to set the switch on the main line to straight-through will set the other switch to straight-through as well (otherwise there is a risk of turning off the track only to find the joining switch is set the wrong way, and running the train through it). Because derailments are expensive and very dangerous to life and limb, maintenance of switch points and other trackwork is essential, especially with faster trains. Another derailment that occurred due to a split switch is the ProRail Hilversum derailment on 15 January 2014.  If the points are rigidly connected to the switch control mechanism, the control mechanism's linkages may be bent, requiring repair before the switch is again usable. For this reason, switches are normally set to the proper position before performing a trailing-point movement.  An example of a mechanism that would require repair after a run-through in the trailing direction is a clamp-lock. This mechanism is popular in the UK, but the damage caused is common to most types of switches.  It would be possible, at least theoretically, to build a rail switch with linkages strong enough that they would not bend under the force of the flanges of train wheels pushing one of the points away from the adjacent fixed rail, so that the points would never move during a trailing-point movement, at least as long as the speed of the train was not excessive. Then, in a trailing-point movement along the route that the points were not set to, the switch would not be damaged, but instead the train would derail. Obviously, it is preferable for the switch to give way and be damaged than for the train to derail, causing damage to it and possible injury or loss of life to people aboard the train or nearby.

Classification.

The divergence and length of a switch is determined by the angle of the frog (the point in the switch where two rails cross, see below) and the angle or curvature of the switch blades. The length and placement of the other components are determined from this using established formulas and standards. This divergence is measured as the number of units of length for a single unit of separation.  In North America this is

Safety.

Switches are crucial to the safe running of a railway because they pose a number of risks:  To avoid accidents

History.

On early lines, vehicles were moved between tracks by means of sliding rails. The switch was patented by Charles Fox in 1832.  Prior to the widespread availability of electricity, switches at heavily travelled junctions were operated from a signal box constructed near the tracks through an elaborate system of rods and levers. The levers

Components.

Points (point blades).

The "points" ("switch rails" or "point blades") are the movable rails which guide the wheels towards either the straight or the diverging track. They are tapered on most switches, but on "stub switches" they have square ends.  In the UK and Commonwealth countries, the term

(common crossing).

The frog, also known as the common crossing (or V-rail in Australian terminology), is the crossing point of two rails. This can be assembled out of several appropriately cut and bent pieces of rail or can be a single casting of manganese steel. On lines with heavy use the casting may be treated with explosive shock hardening to increase service life.  On lines with heavy or high-speed traffic, a swingnose crossing (movable-point frog) may be used. As the name implies, there is a second mechanism located at the frog.

Guard rail (check rail).

A "guard rail" ("check rail") is a short piece of rail placed alongside the main (stock) rail opposite the frog. These ensure that the wheels follow the appropriate flangeway through the frog and that the train

Switch motor.

A "switch motor" (also known as a switch machine, point motor, point machine, or automater) is an electric, hydraulic or pneumatic mechanism that aligns the points with one of the possible routes. The motor is usually controlled remotely by the dispatcher (signaller

Points lever.

A "points lever", "ground throw", or "switchstand" is a lever and accompanying linkages that are used to align the points of a switch manually. This lever and its accompanying hardware is usually mounted to a pair of long sleepers that

Point machine conversion.

A point machine conversion system consist in a remotely controlled device attached to an existing manually operated point that allows

Facing point lock.

A "facing point lock" ("FPL"), or "point lock", is a device which, as the name implies, locks a set of points in position, as well as proving that they are in the correct position. The "facing point" part of the name refers to the fact that they are to prevent movement of the points during facing moves, where a train could potentially "split" the points (end up

Joints.

"Joints" are used where the moving points meet the fixed rails of the switch. They allow the points to hinge easily between their positions. Originally the movable switch

Straight and curved switches.

Turnouts were originally built with straight switch blades, which ended at the pointed end with a sharp angle. These switches cause a bump when the train traverses in the turnout direction. The switch blades could be made with a curved point which meets the stockrail

Point indicators.

As it is difficult to see the lie of a switch from

Types.

Apart from the standard right-hand and left-hand switches, switches commonly come in various combinations of configurations.

Slip switches.

Double slip.

A "double slip switch" ("double slip") is a narrow-angled diagonal flat crossing of two lines combined with four pairs of points in such a way as to allow vehicles to change from one straight track to the other, as well as going straight across. A train approaching the arrangement may leave by either of the two tracks on the opposite side of the crossing. To reach the third possible exit, the train must change tracks on the slip and then reverse.  The arrangement gives the possibility of setting four routes, but because only one route can be traversed at a

Single slip.

A "single slip switch" works on the same principle as a double slip, but provides for only one switching possibility. Trains approaching on one of the two crossing tracks can either continue over the crossing, or switch tracks to the other line. However, trains from the other track can only

Outside slip.

An "outside slip switch" is similar to the double or single slip switches described above, except that the switch blades are outside of the diamond instead of inside. An advantage over an inside slip switch is that trains can pass the slips with higher speeds. A disadvantage over an inside slip switch is that they are longer and need more space.  An outside slip switch can be so long that its slips do not overlap at all, as in the example pictured. In such a case a single, outside slip switch is the same as two regular switches and a regular crossing. An outside, double slip switch is about the same as a "scissors crossover" (see below), but with the disadvantages: Advantage:  Due to the disadvantages over both the "double inside slip switch" and the "scissors crossover", double outside slip switches are only used in rare, specific cases.

Crossover.

A "crossover" is a pair of switches that connects two parallel rail tracks, allowing a train on one track to cross over to the other. Like the switches themselves, crossovers can be described as either "facing" or "trailing".  When two crossovers are present in opposite directions, one after the other, the four-switch configuration is called a "double crossover". If the crossovers in different directions overlap to form an ×, it is dubbed a "scissors crossover", "scissors crossing", or just "scissors"; or, due to the diamond in the center, a "diamond crossover". This makes for a very compact track layout at the expense of using a level junction.  In a setup where each of the two tracks normally carries trains of only one direction, a crossover can be used either to detour "wrong-rail" around an obstruction or to reverse direction. A crossover can also join two tracks of the same direction, possibly a pair of local and express tracks, and allow trains to switch from one to the other.  On a crowded system, routine use of

Stub switch.

A "stub switch" lacks the tapered points (point blades) of a typical switch. Instead, both the movable rails and the ends of the rails of the diverging routes have their ends cut off square. The switch mechanism aligns the movable rails with the rails of one of the diverging routes. In 19th century US railroad use, the stub switch was typically used in conjunction with a harp switch stand.  The rails leading up to a stub switch are not secured to the sleepers for several feet, and rail alignment across the gap is not positively enforced. Stub switches also require some flexibility in the rails (meaning lighter rails), or an extra joint at

Three-way switch.

A "three-way switch" is used to split a railroad track into three divergent paths rather than the more usual two. There are two types of three-way switches. In a "symmetrical three-way switch", the left and right branches diverge at the same place. In an "asymmetrical three-way switch", the branches diverge in a staggered way. Both types of three-way switches require three frogs.  The complexity of symmetrical switches usually results in speed

Plate switch.

A "plate switch" incorporates the tapered points of a typical switch into a self-contained plate. Each point blade is moved separately by hand. Plate switches are only used for double-flanged

Off-railer.

The off-railer is a system of installing a turnout over and above some plain track, without having to cut or replace that track. It is useful for installing

Interlaced turnout.

An "interlaced turnout" is a different method of splitting a track into three divergent paths. It is an arrangement of two standard turnouts, one left- and one right-handed, in an "interlaced" fashion. The points of the second turnout are positioned between the points and the frog of the first turnout. In common with other

Wye switch.

A "wye switch" ("Y points") has trailing ends which diverge symmetrically and in opposite directions. The name originates from the similarity of their shape to that of the letter Y. Wye switches are usually used where space is at a premium. In North America this is also called an "equilateral switch" or "equilateral turnout". Common switches are more often associated with mainline speeds, whereas wye

Run-off points.

"Run-off points" are used to protect main lines from stray or runaway cars, or from trains passing signals set at danger. In these cases, vehicles would otherwise roll onto and foul (obstruct) the main line and cause a collision. Depending on the situation in which they are used, run-off points are referred to either as trap points or catch points. Derailers are another device used for the same purpose.  "Catch points" are installed on the running line itself, where the railway climbs at a steep gradient. They are used to prevent runaway vehicles colliding with another train further down the slope. In some cases, catch points lead into a sand drag to safely stop the runaway vehicle, which may be travelling at speed. Catch points are usually held in the 'derail' position by a spring. They can be set to allow a train to pass safely in the downhill direction using a lever or

Derailers.

A "derailer" works by derailing any vehicle passing over it. There are different types of derailers, but in some cases they consist of a single switch point installed in a track. The point can be pulled into a position to derail any equipment that is not supposed to pass through.

Dual gauge switches.

"Dual gauge switches" are used in dual gauge systems. There are various possible scenarios involving the routes that trains on each gauge may take, including the two gauges separating or one gauge being able to choose between diverging paths and the other not. Because of the extra track involved, dual gauge switches have more points and frogs

Rack railway switches.

Rack railway switches are as varied as rack railway technologies. Where use of the rack is optional, as on the Zentralbahn in Switzerland or the West Coast Wilderness Railway in Tasmania, it is common to place turnouts only in relatively flat areas where the rack is not needed. On systems where only the pinion is driven and the conventional rail wheels are idlers, such as the Dolderbahn in Zürich, Štrbské Pleso in Slovakia and the Schynige Platte rack railway, the rack must be continuous through the

Switch diamond.

Although not strictly speaking a turnout, a "switch diamond" is an active trackwork assembly used where the crossing angle between two tracks is too shallow for totally passive trackwork: the unguided sections of each rail would overlap. These vaguely resemble two standard points assembled very closely toe-to-toe. These would also often utilise swingnose crossings at the outer ends to ensure complete wheel support in the same way as provided on shallow angle turnouts. In North America these are known as "Movable-Point Diamonds". In the UK, where the angle of divergence is shallower than 1 in 8 (center-line measure) a switched diamond will be found rather than a passive or fixed diamond.  Such switches are usually implemented on the basis of increasing the safe crossing speed. Open blades impose a speed restriction, due to the potential of the crossing impact fracturing the rail as both wheels on each axle hit the crossing gaps almost simultaneously. Switched blades, as shown in the photograph, allow a much higher speed across the gap by providing an essentially continuous piece of rail across the gap on both sides.  The frog end of the switched crossing, despite still having a gap in

Expansion joint.

Expansion joints look like a part of a railroad switch, but have a completely different purpose,

Turnout speeds.

Turnout speeds are governed by a number of factors.  As a general rule, the smaller the crossing angle of a turnout, the higher the turnout speed. In North America, turnouts are rated numerically, which represents the ratio of divergence per length as measured at the frog. A rule of thumb is that the rated speed of a switch (in miles per hour) is twice the numerical rating:  Higher speed turnouts have also been used in the United States:  In most other countries, switches are marked with tangent of crossing angle. For example, Russia and the rest of the Commonwealth of Independent States (CIS) use the following designations:  In Germany, Austria, Switzerland, Czech Republic, Poland and

Assembly and transport.

Turnouts are large pieces of rail infrastructure which may be too big, wide, or heavy to transport in one piece. Special wagons can carry the pieces at approximately 45° from vertical, so that they fit within the structure gauge. Once all the pieces have arrived, the turnout is assembled sleeper by sleeper on site. A set of turnouts may be trial assembled beforehand off site, to check that everything fits.

A railroad switch (), turnout, or [set of] points () is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.

Výhybka (dříve se užíval termín „veksl“ (vexl) z něm. "Wechsel" výměna, změna; výhybka) je drážní zařízení v místě, kde se dráhy (např. koleje) rozcházejí nebo sbíhají. Umožňuje jízdu vozidla (případě vedení kladky) do příslušného směru. Kolejová výhybka je součástí železničního svršku nebo svršku tramvajové, lanové, důlní či jiné dráhy. Trolejová výhybka je součástí trolejového vedení pro tyčové sběrače, které se používají na trolejbusových a některých tramvajových drahách. O výhybce lze mluvit i např. u různých druhů dopravníků, potrubní pošty aj.


Definition.

Riboflavin, also known as vitamin B, is a vitamin.

Deficiency.

Signs and symptoms.

Mild deficiencies can exceed 50% of the population in Third World countries and in refugee situations. Deficiency is uncommon in the United States and in other countries that have wheat flour, bread, pasta, corn meal or rice enrichment regulations. In the U.S., starting in the 1940s, flour, corn meal and rice have been fortified with B vitamins as a means of restoring some of what is lost in milling, bleaching and other processing. For adults 20 and older, average intake from food and beverages is 1.8 mg/day for women and 2.5 mg/day for men. An estimated 23% consume a riboflavin-containing dietary supplement that provides on average 10 mg. The U.S. Department of Health and Human Services conducts National Health and Nutrition Examination Survey every two years and reports food results in a series of reports referred to as "What We Eat In America." From NHANES 2011–2012, estimates were that 8% of women and 3% of men consumed less than the RDA. When compared to the lower Estimated Average Requirements, fewer than 3% did not achieve the EAR level.  Riboflavin deficiency (also called ariboflavinosis) results in stomatitis including painful red tongue with sore throat, chapped and fissured lips (cheilosis), and inflammation of the corners of the mouth (angular stomatitis). There can be oily scaly skin rashes on the scrotum, vulva, philtrum of the lip, or the nasolabial folds. The eyes can become itchy, watery, bloodshot and sensitive to light. Due to interference with iron absorption, even mild to moderate riboflavin deficiency results in an anemia with normal cell size and normal hemoglobin content (i.e. normochromic normocytic anemia). This is distinct from anemia caused by deficiency of folic acid (B) or cyanocobalamin (B), which causes anemia with large blood cells (megaloblastic anemia). Deficiency of riboflavin during pregnancy can result in birth defects including congenital heart defects and limb deformities. Prolonged riboflavin insufficiency is also known to cause degeneration of the liver and nervous system.  The stomatitis symptoms are similar to those seen in pellagra, which is caused by niacin (B) deficiency. Therefore, riboflavin deficiency is sometimes called "pellagra sine pellagra" (pellagra without pellagra), because it causes stomatitis but not widespread peripheral skin lesions characteristic of niacin deficiency.  Riboflavin deficiency prolongs recovery from malaria, despite preventing growth of plasmodium (the malaria parasite).

Causes.

Riboflavin is continuously excreted in the urine of healthy individuals, making deficiency relatively common when dietary intake is insufficient. Riboflavin deficiency is usually found together with other nutrient deficiencies, particularly of other water-soluble vitamins. A deficiency of riboflavin can be primary – poor vitamin sources in one's daily diet – or secondary, which may be a result of conditions that affect absorption in the intestine, the body not being able to use the vitamin, or an increase in the excretion of the vitamin from the body.  Subclinical deficiency has also been observed in women taking oral contraceptives, in the elderly, in people with eating disorders, chronic alcoholism and in diseases such as HIV, inflammatory bowel disease, diabetes and chronic heart disease. The Celiac Disease Foundation points out that a gluten-free diet may be low in riboflavin (and other nutrients) as enriched wheat flour and wheat foods (bread, pasta, cereals, etc.) is a major dietary contribution to total riboflavin intake.

Diagnosis.

Overt clinical signs are rarely seen among inhabitants of the developed countries. The assessment of riboflavin status is essential for confirming cases with unspecific symptoms where deficiency is suspected.

Treatment.

Multi-vitamin dietary supplements often contain 100% of the U.S. Daily Value (1.3 mg) for riboflavin, and can be used by persons concerned about an inadequate diet. Over-the-counter dietary supplements are available in the United States with doses as high as 100 mg, but there is no evidence that these high doses have any additional benefit for healthy people.

Medical uses.

Corneal ectasia is a progressive thinning of the cornea; the most common form of this condition is keratoconus. Collagen cross-linking by applying riboflavin topically then shining UV light is a method to slow progression of corneal ectasia by strengthening corneal tissue.  A 2017 review found that riboflavin taken daily in amounts roughly 200 to 400 times the Recommended Dietary Allowance (RDA) may be useful to prevent migraines in adults, but found that clinical trials in adolescents and children had mixed outcomes. A hypothesis has been proposed that riboflavin improves mitochondrial energy production.

Side effects.

In humans, there is no evidence for riboflavin toxicity produced by excessive intakes, in part because it has lower water solubility than other B vitamins, because absorption becomes less efficient as doses increase, and because what exceeds the absorption is excreted via the kidneys into urine. Even when 400 mg of riboflavin per day was given orally to subjects in one study for three months to investigate the efficacy of riboflavin in the prevention of migraine headache, no short-term side effects were reported. Any excess at nutritionally relevant doses is excreted in the urine, imparting a bright yellow color when in large quantities. The limited data available on riboflavin's adverse effects do not mean, however, that high intakes have no adverse effects, and the Food and Nutrition Board urges people to be cautious about consuming excessive amounts of riboflavin.

Function.

Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) function as cofactors for a variety of flavoprotein enzyme reactions:  For the molecular mechanism of action see main articles Flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)

Dietary recommendations.

The National Academy of Medicine (then the U.S. Institute of Medicine [IOM]) updated Estimated Average Requirements (EARs) and Recommended Dietary Allowances (RDAs) for riboflavin in 1998. The current EARs for riboflavin for women and men ages 14 and up are 0.9 mg/day and 1.1 mg/day, respectively; the RDAs are 1.1 and 1.3 mg/day, respectively. RDAs are higher than EARs so as to identify amounts that will cover people with higher than average requirements. RDA for pregnancy is 1.4 mg/day. RDA for lactation is 1.6 mg/day. For infants up to 12 months the Adequate Intake (AI) is 0.3–0.4 mg/day. and for children ages 1–13 years the RDA increases with age from 0.5 to 0.9 mg/day. As for safety, the IOM sets Tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of riboflavin there is no UL, as there is no human data for adverse effects from high doses. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes (DRIs).  The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL defined the same as in United States. For women and men ages 15 and older the PRI is set at 1.6 mg/day. PRI for pregnancy is 1.9 mg/day, for lactation 2.0 mg/day. For children ages 1–14 years the PRIs increase with age from 0.6 to 1.4 mg/day. These PRIs are higher than the U.S. RDAs. The EFSA also reviewed the safety question and like the U.S., decided that there was not sufficient information to set an UL.  For U.S. food and dietary supplement labeling purposes the amount in a serving is expressed as a percent of Daily Value (%DV). For riboflavin labeling purposes 100% of the Daily Value was 1.7 mg, but as of May 27, 2016, it was revised to 1.3 mg to bring it into agreement with the RDA. Compliance with the updated labeling regulations was required by 1 January 2020, for manufacturers with $10 million or more in annual food sales, and by 1 January 2021 for manufacturers with less than $10 million in annual food sales. During the first six months following the 1 January 2020 compliance date, the FDA plans to work cooperatively with manufacturers to meet the new Nutrition Facts label requirements and will not focus on enforcement actions regarding these requirements during that time. A table of the old and new adult Daily Values is provided at Reference Daily Intake.

Sources.

Food and beverages that provide riboflavin without fortification are milk, cheese, eggs, leaf vegetables, liver, kidneys, lean meats, legumes, mushrooms, and almonds.  The milling of cereals results in considerable loss (up to 60%) of vitamin B, so white flour is enriched in some countries by addition of the vitamin. The enrichment of bread and ready-to-eat breakfast cereals contributes significantly to the dietary supply of vitamin B. Polished rice is not usually enriched, because the vitamin's yellow color would make the rice visually unacceptable to the major rice-consuming populations. However, most of the flavin content of whole brown rice is retained if the rice is steamed (parboiled) prior to milling. This process drives the flavins in the germ and aleurone layers into the endosperm. Free riboflavin is naturally present in foods along with protein-bound FMN and FAD. Bovine milk contains mainly free riboflavin, with a minor contribution from FMN and FAD. In whole milk, 14% of the flavins are bound noncovalently to specific proteins. Milk and yogurt contain some of the highest riboflavin content. Egg white and egg yolk contain specialized riboflavin-binding proteins, which are required for storage of free riboflavin in the egg for use by the developing embryo.  Riboflavin is added to baby foods, breakfast cereals, pastas and vitamin-enriched meal replacement products. It is difficult to incorporate riboflavin into liquid products because it has poor solubility in water, hence the requirement for riboflavin-5'-phosphate (E101a), a more soluble form of riboflavin. Riboflavin is also used as a food coloring and as such is designated in Europe as the E number E101.

Chemistry.

As a chemical compound, riboflavin is a yellow-orange solid substance with poor solubility in water compared to other B vitamins. Visually, it imparts color to vitamin supplements (and bright yellow color of urine in persons taking it).

Industrial uses.

Because riboflavin is fluorescent under UV light, dilute solutions (0.015–0.025% w/w) are often used to detect leaks or to demonstrate coverage in an industrial system such a chemical blend tank or bioreactor.

Industrial synthesis.

The industrial scale production of riboflavin using diverse microorganisms, including filamentous fungi such as "Ashbya gossypii", "Candida famata" and "Candida flaveri", as well as the bacteria "Corynebacterium ammoniagenes" and "Bacillus subtilis". The latter organism, genetically modified to both increase the production of riboflavin and to introduce an antibiotic (ampicillin) resistance marker, is employed at a commercial scale to produce riboflavin for feed and food fortification. The chemical company BASF has installed a plant in South Korea, which is specialized on riboflavin production using "Ashbya gossypii". The concentrations of riboflavin in their modified strain are so high that the mycelium has a reddish/brownish color and accumulates riboflavin crystals in the vacuoles, which will eventually burst the mycelium. Riboflavin is sometimes overproduced, possibly as a protective mechanism, by some bacteria in the presence of high concentrations of hydrocarbons or aromatic compounds. One such organism is "Micrococcus luteus" (American Type Culture Collection strain number ATCC 49442), which develops a yellow color due to production of riboflavin while growing on pyridine, but not when grown on other substrates, such as succinic acid.

History.

The name "riboflavin" comes from "ribose" (the sugar whose reduced form, ribitol, forms part of its structure) and "flavin", the ring-moiety which imparts the yellow color to the oxidized molecule (from Latin "flavus", "yellow"). The reduced form, which occurs in metabolism along with the oxidized form, is colorless.  "Vitamin B" was originally considered to have two components, a heat-labile vitamin B and a heat-stable vitamin B. In the 1920s, vitamin B was initially thought to be the factor necessary for preventing pellagra. In 1923, Paul Gyorgy in Heidelberg was investigating egg-white injury in rats; the curative factor for this condition was called vitamin H, which is now called biotin. Since both pellagra and vitamin H deficiency were associated with dermatitis, Gyorgy decided to test the effect of vitamin B on vitamin H deficiency in rats. He enlisted the service of Wagner-Jauregg in Kuhn's laboratory. In 1933, Kuhn, Gyorgy, and Wagner found that thiamin-free extracts of yeast, liver, or rice bran prevented the growth failure of rats fed a thiamin-supplemented diet.  Further, the researchers noted that a yellow-green fluorescence in each extract promoted rat growth, and that the intensity of fluorescence was proportional to the effect on growth. This observation enabled them to develop a rapid chemical and bioassay to isolate the factor from egg white in 1933. The same group then isolated the same preparation (a growth-promoting compound with yellow-green fluorescence) from whey using the same procedure (lactoflavin). In 1934, Kuhn's group identified the structure of so-called flavin and synthesized vitamin B, leading to evidence in 1939 that riboflavin was essential for human health.

Research.

Donated whole blood can be treated with riboflavin and then with ultraviolet light as a pathogen reduction technology.

Riboflavin, also known as vitamin B, is a vitamin found in food and used as a dietary supplement. It is required by the body for cellular respiration. Food sources include eggs, green vegetables, milk and other dairy product, meat, mushrooms, and almonds. Some countries require its addition to grains.

Riboflavin (vitamín B, vitamín G, ovoflavin, laktoflavin) je žluté až oranžově žluté přírodní barvivo slabě rozpustné ve vodě. Patří mezi flaviny. Fluoreskuje, je odolný vůči vysokým teplotám, ale rozkládá se působením světla.


Content.

The first part of the Book of Enoch describes the fall of the Watchers, the angels who fathered the Nephilim. The remainder of the book describes Enoch's visits to heaven in the form of travels, visions and

Canonicity.

Judaism.

Although evidently widely known during the development of the Hebrew Bible canon, 1 Enoch was excluded from both the formal canon of the Tanakh and the typical canon of the Septuagint and therefore, also from the writings known today as the Deuterocanon. One possible reason for Jewish rejection of the book might be the textual nature of several early sections of the book that make use of material from the Torah; for example, 1 En 1 is a midrash of

Christianity.

By the 4th century, the Book of Enoch was mostly excluded from Christian canons, and it is now regarded as scripture by only the Ethiopian Orthodox Tewahedo Church and the Eritrean Orthodox Tewahedo Church.

References in the New Testament.

"Enoch, the seventh from Adam" is quoted, in : Compare this with Enoch 1:9, translated from the Ethiopic (found also in Qumran scroll 4Q204=4QEnoch ar, col I 16–18): Compare this also with what may be the original source of 1 En 1:9 in Deuteronomy 33:2: Under the heading of canonicity, it is not enough to merely demonstrate that something is quoted. Instead, it is necessary to demonstrate the nature of the quotation. In the case of the Jude 1:14 quotation of 1 Enoch 1:9, it would be difficult to argue that Jude does not quote Enoch as a historical prophet since he cites Enoch by name. However, there remains a question as to whether the author of Jude attributed the quotation believing the source to be the historical Enoch before the flood or a midrash of Deut 33:2–3. The Greek text might

Reception.

The Book of Enoch was considered as scripture in the Epistle of Barnabas (16:4) and by many of the early Church Fathers, such as Athenagoras, Clement of Alexandria, Irenaeus and Tertullian,

Ethiopian Orthodox Church.

The belief of the Ethiopian Orthodox Church, which sees 1 Enoch as an inspired document, is that the Ethiopic text is the

The Church of Jesus Christ of Latter-day Saints.

The Church of Jesus Christ of Latter-day Saints (LDS Church), the largest denomination within the Latter Day Saint movement does not consider 1 Enoch to be part of its standard canon, although it believes that a purported "original" Book of Enoch was an inspired book. The Book of Moses, first published in the 1830s, is part of the scriptural canon of the LDS Church and has a section which claims to contain extracts from the "original" Book of Enoch. This section has many similarities to 1 Enoch and other Enoch texts, including 2 Enoch, 3 Enoch, and "The Book of Giants". The Enoch section of the Book of Moses is believed by the Church to contain extracts from "the ministry, teachings, and visions of Enoch", though it does not contain the entire Book of Enoch itself. The LDS Church would therefore consider the portions of the other texts which match its Enoch excerpts to be inspired, while not rejecting but withholding judgment on the remainder.

Manuscript tradition.

Ethiopic.

The most extensive witnesses to the Book of Enoch exist in the Ge'ez language. Robert Henry Charles's critical edition of 1906 subdivides the Ethiopic manuscripts into two families:  Family α: thought to be more ancient

Aramaic.

Eleven Aramaic-language fragments of the Book of Enoch were found in cave 4 of Qumran in 1948 and are in the care of the Israel Antiquities Authority. They were translated for and discussed by Józef Milik and Matthew Black in "The

Greek and Latin.

The 8th-century work "Chronographia Universalis" by the Byzantine historian George Syncellus preserved some passages of the Book of Enoch in Greek (6:1–9:4, 15:8–16:1). Other Greek fragments known are: It has been claimed that several small additional fragments in Greek have been found at Qumran (7QEnoch:

History.

Second Temple period.

The 1976 publication by Milik of the results of the paleographic dating of the Enochic fragments found in Qumran made a breakthrough. According to this scholar, who studied the original scrolls for many years, the oldest fragments of the Book of Watchers are dated to 200–150 BC. Since the Book of Watchers shows evidence of multiple stages of composition, it is probable that this work was extant already in the 3rd century BC. The same can be said about the Astronomical Book.  It was no longer possible to claim that the core of the Book of Enoch was composed in the wake of the Maccabean Revolt as a reaction to Hellenization. Scholars thus had to look for the origins of the Qumranic sections of 1 Enoch in the previous historical period, and the

Early influence.

Classical rabbinic literature is characterized by near silence concerning Enoch. It seems plausible that Rabbinic polemics against Enochic texts and traditions might have led to the loss of these books to Rabbinic Judaism.  The Book of Enoch plays an important role in the history of Jewish mysticism: the scholar Gershom Scholem wrote, "The main subjects of the later Merkabah mysticism already occupy a central position in the older esoteric literature, best represented by the "Book of Enoch"." Particular attention is paid to the detailed description of the throne of God included in chapter 14 of 1 Enoch.  For the quotation from the Book of Watchers in the New Testament Epistle of Jude, see section: Canonicity.  There is

Rediscovery.

Sir Walter Raleigh, in his "History of the World" (written in 1616 while imprisoned in the Tower of London), makes the curious assertion that part of the Book of Enoch "which contained the course of the stars, their names and motions" had been discovered in Saba (Sheba) in the first century and was thus available to Origen and Tertullian. He attributes this information to Origen, though no such statement is found anywhere in extant versions of Origen.  Outside of Ethiopia, the text of the Book of Enoch was considered lost until the beginning of the seventeenth century, when it was confidently asserted that the book was found in an Ethiopic (Ge'ez) language translation there, and Nicolas-Claude Fabri de Peiresc bought a book that was claimed to

The Book of the Watchers.

This first section of the Book of Enoch describes the fall of the Watchers, the angels who fathered the Nephilim (cf. the "bne Elohim", ) and narrates the travels of Enoch in the heavens. This section is said to have been composed in the 4th or 3rd century BC according to Western scholars.

Description.

The introduction to the Book of Enoch tells us that Enoch is "a just man, whose eyes were opened by God so that he saw a vision of the Holy One in the heavens, which the sons of God showed to me, and from them I heard everything, and I knew what I saw, but [these things that I saw will] not [come to pass] for this generation, but for a generation that has yet to come."  It discusses God coming to Earth on Mount Sinai with His hosts to pass judgement on mankind. It also tells us about the luminaries rising and setting in the order and in their own time and never change:  "Observe and see how (in the winter) all the trees seem as though they had withered and shed all their leaves, except fourteen trees, which do not lose their foliage but retain the old foliage from two to three years till the new comes."  How all things are ordained by God and take place in his own time. The sinners shall perish and the great

Book of Parables.

Chapters 37–71 of the Book of Enoch are referred to as the Book of Parables. The scholarly debate centers on these chapters. The Book of Parables appears to be based on the Book of Watchers, but presents a later development of the idea of final judgement and of eschatology, concerned not only with the destiny of the fallen angels but also that of the evil kings of the earth. The Book of Parables uses the expression "Son of Man" for the eschatological protagonist, who is also called “Righteous One”, “Chosen One”, and “Messiah”, and sits on the throne of glory in the final judgment. The first known use of "The Son of Man" as a definite title in Jewish writings is in 1 Enoch, and its use may have played a role in the early Christian understanding and use of the title.  It has been suggested that the Book of Parables, in its entirety, is a later addition. Pointing to similarities with the Sibylline Oracles and other earlier works, in 1976, J.T. Milik dated the Book of Parables to the third century. He believed that the events in the parables were linked to historic events dating from 260 to 270 CE. This theory is in line with the beliefs of many scholars of the 19th century, including Lucke (1832), Hofman (1852), Wiesse (1856), and Phillippe (1868). According to this theory, these chapters were written in later Christian times by a Jewish Christian to enhance Christian beliefs with Enoch's authoritative name. In a 1979 article, Michael Knibb followed Milik's reasoning and suggested that because no fragments of chapters 37–71 were found at Qumran, a later date was likely. Knibb would continue this line of reasoning in later works. In addition to being missing from Qumran, Chapters 37–71 are also missing from the Greek translation. Currently no firm consensus has been reached among scholars as to the date of the writing of the Book of Parables. Milik's date of as late as 270 CE, however, has been rejected by most scholars. David W. Suter suggests that there is a tendency to date the Book of Parables to between 50 BC and 117 AD.  In 1893, Robert Charles judged Chapter 71 to be a later addition. He would later change his opinion and give an early date for the work between 94 and 64 BC. The 1906 article by Emil G. Hirsch in the "Jewish Encyclopedia" states that "Son of Man" is found in the Book of Enoch, but never in the original material. It occurs in the "Noachian interpolations" (lx. 10, lxxi. 14), in which it has clearly no other meaning than'man'. The author of the work misuses or corrupts the titles of the angels. Charles views the title "Son of Man", as found in the Book of Parables, as referring to a supernatural person, a Messiah who is not of human descent. In that part of the Book of Enoch known as the Similitudes, it has the technical sense of a supernatural Messiah and judge of the world (xlvi. 2, xlviii. 2, lxx. 27); universal dominion and preexistence are predicated of him (xlviii. 2, lxvii. 6). He sits on God's throne (xlv. 3, li. 3), which is his own throne. Though Charles does not admit it, according to Emil G. Hirsch these passages betray Christian redaction and emendation. Many scholars have suggested that passages in the Book of Parables are Noachian interpolations. These passages seem to interrupt the flow of the narrative. Darrell D. Hannah suggests that these passages are not, in total, novel interpolations, but rather derived from an earlier Noah apocryphon. He believes that some interpolations refer to Herod the Great and should be dated to around 4 BC.  In addition to the theory of Noachian interpolations, which perhaps a majority of scholars support, most scholars currently believe that Chapters 70–71 are a later addition in part or in whole. Chapter 69 ends with, "This is the third parable of Enoch." Like Elijah, Enoch is generally thought to have been brought up to Heaven by God while still alive, but some have suggested that the text refers to Enoch as having died a natural death and ascending to Heaven. The Son of Man is identified with Enoch. The text implies that Enoch had previously been enthroned in heaven. Chapters 70–71 seem to contradict passages earlier in the parable where the Son of Man is a separate entity. The parable also switches from third person singular to first person singular. James H. Charlesworth rejects the theory that chapters 70–71 are later additions. He believes that no additions were made to the Book of Parables. In his earlier work, the implication is that a majority of scholars agreed with him.

The Astronomical Book.

Four fragmentary editions of the Astronomical Book were found at Qumran, 4Q208-211. 4Q208 and 4Q209 have been dated to the beginning of the 2nd century BC, providing a "terminus ante quem" for the Astronomical Book of the 3rd century BC. The fragments found in Qumran also include material not contained in the later versions of the Book of Enoch.  This book contains descriptions of the movement of heavenly bodies and of the firmament, as a knowledge revealed to Enoch in his trips to Heaven guided by Uriel, and it describes a Solar calendar that was later described also in the Book of Jubilees which was used

The Dream Visions.

The Book of Dream Visions, containing a vision of a history of Israel all the way down to what the majority have interpreted as the Maccabean Revolt, is dated by most to Maccabean times (about 163–142 BC). According to the Ethiopian Orthodox Church it was written before the Flood.

Animals in the second dream vision.

The second dream vision in this section of the Book of Enoch is an allegorical account of the history of Israel, that uses animals

Description.

There are a great many links between the first book and this one, including the outline of the story and the imprisonment of the leaders and destruction of the Nephilim. The dream includes sections relating to the book of Watchers: And those seventy shepherds were judged and found guilty, and they were cast into that fiery abyss. And I saw at that time how a like abyss was opened in the midst of the earth, full of fire, and they brought those blinded sheep. (The fall of the evil ones)  And all the oxen feared them and were affrighted at them, and began to bite with their teeth and to devour, and to gore with their horns. And they began, moreover, to devour those oxen; and behold all the children of the earth began to tremble and quake before them and to flee from them. (The creation of the Nephilim et al.)  86:4, 87:3, 88:2, and 89:6 all describe the types of Nephilim that are created during the times described in The Book of Watchers, though this doesn't mean that the authors of both books are the same. Similar references exist in Jubilees 7:21–22.  The book describes their release from the Ark along with three bulls – white, red, and black, which are Shem, Ham, and Japeth – in 90:9. It also covers the death of Noah, described as the white bull, and the creation of many nations:  And they began to bring forth beasts of the field and birds, so that there arose different genera: lions, tigers, wolves, dogs, hyenas, wild boars, foxes, squirrels, swine, falcons, vultures, kites, eagles, and ravens (90:10)  It then describes the story of Moses

The Epistle of Enoch.

Some scholars propose a date somewhere between the 170 BC and the 1st

Names of the fallen angels.

Some of the fallen angels that are given in 1 Enoch have other names, such as "Rameel" ('morning of God'), who becomes Azazel, and is also called "Gadriel" ('wall of God') in Chapter 68. Another example is that "Araqiel" ('Earth of God') becomes "Aretstikapha" ('world of distortion') in Chapter 68.  "Azaz", as in "Azazel", means strength, so the name "Azazel" can refer to'strength of God'. But the sense in which it is used most probably means 'impudent' (showing strength towards), which results in 'arrogant to God'. This is also a key point in modern thought that Azazel is Satan. Also important in this identification is the fact that the original name Rameel, is very similar in meaning to the word Lucifer ('Morning Star') which is a common Latin name of Satan in Christianity.  Nathaniel Schmidt states "the names of the angels apparently refer to their condition and functions before the fall," and lists the likely meanings of the angels' names in the Book of Enoch, noting that "the great majority of them are Aramaic."  The name suffix "-el" means 'God' (see list of names referring to El), and is used in the names of high-ranking angels. The archangels' names all include "-el", such as "Uriel" ('flame of God') and "Michael" ('who is like God').  Another name is given as "Gadreel", who is said to have tempted Eve; Schmidt lists the name as meaning 'the helper of God.'

The Book of Enoch (also 1 Enoch; Ge'ez: መጽሐፈ ሄኖክ "maṣḥafa hēnok") is an ancient Hebrew apocalyptic religious text, ascribed by tradition to Enoch, the great-grandfather of Noah. Enoch contains unique material on the origins of demons and giants, why some angels fell from heaven, an explanation of why the Great Flood was morally necessary, and prophetic exposition of the thousand-year reign of the Messiah.

1. kniha Henochova (též Etiopský Henoch) je jedním z nejznámějších starozákonních apokryfů. Je to celkem pět původně samostatných knih, které jsou spojeny postavou Henochovou. Henoch je jako prastará biblická postava příjemcem nadpřirozených zjevení o běhu a podstatě světa. Kniha spadá do apokalyptického žánru a některé její části jsou typickými a ryzími apokalypsami.