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Vectran
Vectran is a manufactured fiber, spun from a liquid-crystal polymer (LCP) created by Celanese Corporation and now manufactured by Kuraray. Chemically it is an aromatic polyester produced by the polycondensation of 4-hydroxybenzoic acid and 6-hydroxynaphthalene-2-carboxylic acid. Properties Advantages Vectran's golden fibers are noted for their thermal stability at high temperatures, high strength and modulus, low creep, and good chemical stability. They are moisture-resistant and generally stable in hostile environments. Polyester coating is often used around a Vectran core; polyurethane coating can improve abrasion resistance and act as a water barrier. Vectran has a melting point of 330 °C, with progressive strength loss from 220 °C. Disadvantages Although the tensile strength is similar to Kevlar, Vectran still tends to experience tensile fractures when exposed to significant stress. The wispy, hair-like fibers tend to fray, to easily acquire dirt, and to re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid-crystal Polymer
Liquid crystal polymers (LCPs) are polymers with the property of liquid crystal, usually containing aromatic rings as mesogens. Despite uncrosslinked LCPs, polymeric materials like liquid crystal elastomers (LCEs) and liquid crystal networks (LCNs) can exhibit liquid crystallinity as well. They are both crosslinked LCPs but have different cross link density. They are widely used in the digital display market. In addition, LCPs have unique properties like thermal actuation, anisotropic swelling, and soft elasticity. Therefore, they can be good actuators and sensors. One of the most famous and classical applications for LCPs is Kevlar, a strong but light fiber with wide applications including bulletproof vests. Background Liquid crystallinity in polymers may occur either by dissolving a polymer in a solvent ( lyotropic liquid-crystal polymers) or by heating a polymer above its glass or melting transition point ( thermotropic liquid-crystal polymers). Liquid-crystal polymer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bigelow Aerospace
Bigelow Aerospace is an American aeronautics and outer space technology company which manufactures and develops expandable space station modules. Bigelow Aerospace was founded by Robert Bigelow in 1998, and is based in North Las Vegas, Nevada. It is funded in large part by the profit Bigelow gained through his ownership of the hotel chain, Budget Suites of America. By 2013, Bigelow had invested US$250 million in the company. Bigelow stated on a number of occasions that he was prepared to fund Bigelow Aerospace with about US$500 million through 2015 in order to achieve launch of full-scale hardware. Bigelow Aerospace announced in 2010 that they intended to create a modular set of space habitats for creating or expanding space stations but despite many concepts and models, never completed a working space station beyond two small prototypes that flew in 2006 and 2007. In March 2020, the company laid off all 88 of its employees due to the COVID-19 pandemic, and planned to rehire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Pathfinder
''Mars Pathfinder'' (''MESUR Pathfinder'') is an American robotic spacecraft that landed a base station with a roving probe on Mars in 1997. It consisted of a lander, renamed the Carl Sagan Memorial Station, and a lightweight, wheeled robotic Mars rover named ''Sojourner'', the first rover to operate outside the Earth–Moon system. Launched on December 4, 1996, by NASA aboard a Delta II booster a month after the '' Mars Global Surveyor'', it landed on July 4, 1997, on Mars's Ares Vallis, in a region called Chryse Planitia in the Oxia Palus quadrangle. The lander then opened, exposing the rover which conducted many experiments on the Martian surface. The mission carried a series of scientific instruments to analyze the Martian atmosphere, climate, and geology and the composition of its rocks and soil. It was the second project from NASA's Discovery Program, which promotes the use of low-cost spacecraft and frequent launches under the motto "cheaper, faster and better" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formula Liquid-Crystal-Polymer
In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship between given quantities. The plural of ''formula'' can be either ''formulas'' (from the most common English plural noun form) or, under the influence of scientific Latin, ''formulae'' (from the original Latin). In mathematics In mathematics, a formula generally refers to an identity which equates one mathematical expression to another, with the most important ones being mathematical theorems. Syntactically, a formula (often referred to as a ''well-formed formula'') is an entity which is constructed using the symbols and formation rules of a given logical language. For example, determining the volume of a sphere requires a significant amount of integral calculus or its geometrical analogue, the method of exhaustion. However, having done ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Bridges And Tunnels In New York City
New York City is home to many bridges and tunnels. Several agencies manage this network of crossings. The New York City Department of Transportation owns and operates almost 800. The Metropolitan Transportation Authority, Port Authority of New York and New Jersey, New York State Department of Transportation and Amtrak have many others. Many of the city's major bridges and tunnels have broken or set records. Opened in 1927, the Holland Tunnel was the world's first mechanically ventilated underwater vehicular tunnel. The Brooklyn Bridge, Williamsburg Bridge, George Washington Bridge, and Verrazzano-Narrows Bridge were the world's longest suspension bridges when opened in 1883, 1903, 1931, and 1964 respectively. There are 789 bridges and tunnels in New York. Bridges New York City's crossings date back to 1693, when its first bridge, known as the King's Bridge, was constructed over Spuyten Duyvil Creek between Manhattan and the Bronx, located in the present-day Kingsbridge neighbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York City Subway
The New York City Subway is a rapid transit system owned by the government of New York City and leased to the New York City Transit Authority, an affiliate agency of the state-run Metropolitan Transportation Authority (MTA). Opened on October 27, 1904, the New York City Subway is one of the world's oldest public transit systems, one of the most-used, and the one with the most stations, with 472 stations in operation (424 if stations connected by transfers are counted as single stations). Stations are located throughout the boroughs of Manhattan, Brooklyn, Queens, and the Bronx. The system has operated 24/7 service every day of the year throughout most of its history, barring emergencies and disasters. By annual ridership, the New York City Subway is the busiest rapid transit system in both the Western Hemisphere and the Western world, as well as the seventh-busiest rapid transit rail system in the world. In , the subway delivered rides, or about per weekday as of . On Octo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Department Of Homeland Security
The United States Department of Homeland Security (DHS) is the U.S. federal executive department responsible for public security, roughly comparable to the interior or home ministries of other countries. Its stated missions involve anti-terrorism, border security, immigration and customs, cyber security, and disaster prevention and management. It began operations in 2003, formed as a result of the Homeland Security Act of 2002, enacted in response to the September 11 attacks. With more than 240,000 employees, DHS is the third-largest Cabinet department, after the Departments of Defense and Veterans Affairs. Homeland security policy is coordinated at the White House by the Homeland Security Council. Other agencies with significant homeland security responsibilities include the Departments of Health and Human Services, Justice, and Energy. History Creation In response to the September 11 attacks, President George W. Bush announced the establishment of the Office of H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Scientist
''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishes a monthly Dutch-language edition. First published on 22 November 1956, ''New Scientist'' has been available in online form since 1996. Sold in retail outlets (paper edition) and on subscription (paper and/or online), the magazine covers news, features, reviews and commentary on science, technology and their implications. ''New Scientist'' also publishes speculative articles, ranging from the technical to the philosophical. ''New Scientist'' was acquired by Daily Mail and General Trust (DMGT) in March 2021. History Ownership The magazine was founded in 1956 by Tom Margerison, Max Raison and Nicholas Harrison as ''The New Scientist'', with Issue 1 on 22 November 1956, priced at one shilling (a twentieth of a pound in pre-decimal UK ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program, aeronautics research, and outer space, space research. NASA was National Aeronautics and Space Act, established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo program, Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion (spacecraft), Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew Program, Commercial Crew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bigelow Expandable Activity Module
The Bigelow Expandable Activity Module (BEAM) is an experimental expandable space station module developed by Bigelow Aerospace, under contract to NASA, for testing as a temporary module on the International Space Station (ISS) from 2016 to at most 2028, when the contract can not be extended any further. It arrived at the ISS on 10 April 2016, was berthed to the station on 16 April 2016, and was expanded and pressurized on 28 May 2016. Although originally planned to be a two year test, it has exceeded expectations and is used as additional cargo storage. The module is under ownership of NASA after Bigelow Aerospace suspended operations in 2021. History NASA originally considered the idea of inflatable habitats in the 1960s, and developed the TransHab inflatable module concept in the late 1990s. The TransHab project was canceled by Congress in 2000, and Bigelow Aerospace purchased the rights to the patents developed by NASA to pursue private space station designs. In 2006 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Science Laboratory
Mars Science Laboratory (MSL) is a robotic space probe mission to Mars launched by NASA on November 26, 2011, which successfully landed ''Curiosity'', a Mars rover, in Gale Crater on August 6, 2012. The overall objectives include investigating Mars' habitability, studying its climate and geology, and collecting data for a human mission to Mars. The rover carries a variety of scientific instruments designed by an international team. Overview MSL successfully carried out the most accurate Martian landing of any known spacecraft at the time, hitting a small target landing ellipse of only , in the Aeolis Palus region of Gale Crater. In the event, MSL achieved a landing east and north of the center of the target. This location is near the mountain Aeolis Mons (a.k.a. "Mount Sharp"). The rover mission is set to explore for at least 687 Earth days (1 Martian year) over a range of . The Mars Science Laboratory mission is part of NASA's Mars Exploration Program, a long-term e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Exploration Rover
NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, '' Spirit'' and '' Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rovers to explore the Martian surface and geology; both landed on Mars at separate locations in January 2004. Both rovers far outlived their planned missions of 90 Martian solar days: MER-A ''Spirit'' was active until March 22, 2010, while MER-B ''Opportunity'' was active until June 10, 2018. Objectives The mission's scientific objective was to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. The mission is part of NASA's Mars Exploration Program, which includes three previous successful landers: the two Viking program landers in 1976 and Mars Pathfinder probe in 1997. The total cost of building, launching, landing and operating the rovers on the surface for the initial 90-sol primary mission was US$820 mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
