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Avenger-class Mine Countermeasures Ship
''Avenger''-class mine countermeasures ships are a class of 14 ships constructed for the United States Navy from 1987 to 1994, designed to clear mines from vital waterways. The ships have the hull designator MCM. The ''Avenger''-class ships are being replaced by the ''Freedom'' and s, as well as other MCM platforms, which use various unmanned air, surface, and undersea vehicles to detect and destroy naval mines at a standoff distance. History Background In the early 1980s, the U.S. Navy began development of a new mine countermeasures (MCM) force, which included two new classes of ships and minesweeping helicopters. The vital importance of a state-of-the-art mine countermeasures force was strongly underscored in the Persian Gulf during the eight years of the Iran–Iraq War, and in Operations Desert Shield and Desert Storm in 1990 and 1991 when ''Avenger'' and ''Guardian'' conducted MCM operations. ''Avenger''-class ships are designed as mine hunter-killers capable of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iran–Iraq War
The Iran–Iraq War was an armed conflict between Iran and Iraq that lasted from September 1980 to August 1988. It began with the Iraqi invasion of Iran and lasted for almost eight years, until the acceptance of United Nations Security Council Resolution 598 by both sides. Iraq's primary rationale for the attack against Iran cited the need to prevent Ruhollah Khomeini—who had spearheaded Iran's Islamic Revolution in 1979—from exporting the new Iranian ideology to Iraq; there were also fears among the Iraqi leadership of Saddam Hussein that Iran, a theocratic state with a population predominantly composed of Shia Muslims, would exploit sectarian tensions in Iraq by rallying Iraq's Shia majority against the Baʽathist government, which was officially secular and dominated by Sunni Muslims. Iraq also wished to replace Iran as the power player in the Persian Gulf, which was not seen as an achievable objective prior to the Islamic Revolution because of Pahlavi Iran's economi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Douglas Fir
The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three varieties: coast Douglas-fir (''P. menziesii'' var. ''menziesii''), Rocky Mountain Douglas-fir (''P. menziesii'' var. ''glauca'') and Mexican Douglas-fir (''P. menziesii'' var. ''lindleyana''). Despite its common names, it is not a true fir (genus ''Abies''), spruce (genus '' Picea''), or pine (genus ''Pinus''). It is also not a hemlock; the genus name ''Pseudotsuga'' means "false hemlock". Description Douglas-firs are medium-size to extremely large evergreen trees, tall (although only ''Pseudotsuga menziesii var. menziesii'', common name coast Douglas-firs, reach heights near 100 m) and commonly reach in diameter, although trees with diameters of almost exist. The largest coast Douglas-firs regularly live over 500 years, with the old ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fiberglass
Fiberglass (American English) or fibreglass (Commonwealth English) is a common type of fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth. The plastic matrix may be a thermoset polymer matrix—most often based on thermosetting polymers such as epoxy, polyester resin, or vinyl ester resin—or a thermoplastic. Cheaper and more flexible than carbon fiber, it is stronger than many metals by weight, non- magnetic, non-conductive, transparent to electromagnetic radiation, can be molded into complex shapes, and is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools, hot tubs, septic tanks, water tanks, roofing, pipes, cladding, orthopedic casts, surfboards, and external door skins. Other common names for fiberglass are glass-reinforced plastic (GRP), glass-fiber reinforced plastic (GFRP) or GF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wood
Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or woodchips or fiber. Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the productio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Program Of Iran
The nuclear program of Iran is an ongoing scientific effort by Iran to research nuclear technology that can be used to make nuclear weapons. Iran has several research sites, two uranium mines, a research reactor, and uranium processing facilities that include three known uranium enrichment plants. Iran's nuclear program was launched in the 1950s with the help of the United States under the Atoms for Peace program, and in 1970, Iran ratified the Non-Proliferation Treaty (NPT), limiting its nuclear program to peaceful use, and making its nuclear program subject to inspection by the International Atomic Energy Agency (IAEA). Western cooperation ceased following the 1979 Iranian Revolution, after which Iran continued its nuclear program on a clandestine basis. In the 2000s, the revelation of Iran's clandestine uranium enrichment program raised concerns that the program might be intended for non-peaceful uses. The IAEA launched an investigation in 2003 after an Iranian dissident gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strait Of Hormuz
The Strait of Hormuz ( fa, تنگه هرمز ''Tangeh-ye Hormoz'' ar, مَضيق هُرمُز ''Maḍīq Hurmuz'') is a strait between the Persian Gulf and the Gulf of Oman. It provides the only sea passage from the Persian Gulf to the open ocean and is one of the world's most strategically important choke points. On the north coast lies Iran, and on the south coast lies the Musandam peninsula, shared by the United Arab Emirates and Musandam Governorate, an exclave of Oman. The strait is about long, with a width varying from about to . A third of the world's liquefied natural gas and almost 25% of total global oil consumption passes through the strait, making it a highly important strategic location for international trade. Etymology The opening to the Persian Gulf was described, but not given a name, in the ''Periplus of the Erythraean Sea'', a 1st-century mariner's guide: In the 10th17th centuries AD, the Kingdom of Ormus, which seems to have given the strait ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manama
Manama ( ar, المنامة ', Bahrani Arabic, Bahrani pronunciation: ) is the capital and largest city of Bahrain, with an approximate population of 200,000 people as of 2020. Long an important trading center in the Persian Gulf, Manama is home to a very diverse population. After periods of Portuguese Empire, Portuguese and Persian control and invasions from the ruling dynasties of House of Saud, Saudi Arabia and House of Al Said, Oman, Bahrain established itself as an sovereign state, independent nation in 1971 after a period of British hegemony. Although the current twin cities of Manama and Muharraq appear to have been founded simultaneously in the 1800s, Muharraq took prominence due to its defensive location and was thus the capital of Bahrain until 1923. Manama became the mercantile capital and was the gateway to the main Bahrain Island. In the 20th century, Bahrain's oil wealth helped spur fast growth and in the 1990s a concerted diversification (marketing strategy), d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sasebo
is a core city located in Nagasaki Prefecture, Japan. It is also the second largest city in Nagasaki Prefecture, after its capital, Nagasaki. On 1 June 2019, the city had an estimated population of 247,739 and a population density of 581 persons per km2 (1,505 persons per square mile). The total area is . The city includes a part of Saikai National Park. Located in the southern part of the city is the Dutch-styled theme park ''Huis Ten Bosch''. The island of Ukujima is also administered as part of Sasebo city. History The area of present-day Sasebo was a small fishing village under the control of nearby Hirado Domain until shortly after the start of the Meiji period. Imperial Japanese Navy Admiral Tōgō Heihachirō, when surveying the coasts of northwestern Kyūshū for the site of a navy base, selected his location based on its protected, deep-water harbor, geographic proximity to China and Korea, and the presence of nearby coal fields. Sasebo Naval District, founded in 1886, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonar
Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigation, navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels. "Sonar" can refer to one of two types of technology: ''passive'' sonar means listening for the sound made by vessels; ''active'' sonar means emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of "targets" in the water. Acoustic location in air was used before the introduction of radar. Sonar may also be used for robot navigation, and SODAR (an upward-looking in-air sonar) is used for atmospheric investigations. The term ''sonar'' is also used for the equipment used to generate and receive the sound. The acoustic frequencies used in sonar systems vary from very low (infrasonic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
