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Anti-aircraft Guns Of Czechoslovakia
Anti-aircraft warfare, counter-air or air defence forces is the battlespace response to aerial warfare, defined by NATO as "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It includes surface based, subsurface ( submarine launched), and air-based weapon systems, associated sensor systems, command and control arrangements, and passive measures (e.g. barrage balloons). It may be used to protect naval, ground, and air forces in any location. However, for most countries, the main effort has tended to be homeland defence. NATO refers to airborne air defence as counter-air and naval air defence as anti-aircraft warfare. Missile defence is an extension of air defence, as are initiatives to adapt air defence to the task of intercepting any projectile in flight. In some countries, such as Britain and Germany during the Second World War, the Soviet Union, and modern NATO and the United States, ground-based air defence and air defence aircr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abbreviation
An abbreviation (from Latin ''brevis'', meaning ''short'') is a shortened form of a word or phrase, by any method. It may consist of a group of letters or words taken from the full version of the word or phrase; for example, the word ''abbreviation'' can itself be represented by the abbreviation ''abbr.'', ''abbrv.'', or ''abbrev.''; ''NPO'', for nil (or nothing) per (by) os (mouth) is an abbreviated medical instruction. It may also consist of initials only, a mixture of initials and words, or words or letters representing words in another language (for example, e.g., i.e. or RSVP). Some types of abbreviations are acronyms (some pronounceable, some initialisms) or grammatical contractions or crasis. An abbreviation is a shortening by any of these or other methods. Different types of abbreviation Acronyms, initialisms, contractions and crasis share some semantic and phonetic functions, and all four are connected by the term "abbreviation" in loose parlance. A initialism is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zenith
The zenith (, ) is an imaginary point directly "above" a particular location, on the celestial sphere. "Above" means in the vertical direction (plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" point on the celestial sphere. Origin The word "zenith" derives from an inaccurate reading of the Arabic expression (), meaning "direction of the head" or "path above the head", by Medieval Latin scribes in the Middle Ages (during the 14th century), possibly through Old Spanish. It was reduced to "samt" ("direction") and miswritten as "senit"/"cenit", the "m" being misread as "ni". Through the Old French "cenith", "zenith" first appeared in the 17th century. Relevance and use The term ''zenith'' sometimes means the highest point, way, or level reached by a celestial body on its daily apparent path around a given point of observation. This sense of the word is often used to describe the position of the Sun ("The sun reached its zenit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
