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V4 Engines
V4 or V-4 may refer to: Science and technology * LNER Class V4, a British steam locomotive * V4 engine, a V engine with four cylinders in two banks of two cylinders * Visual area V4, in the visual cortex * Klein four-group, in mathematics * V.4, an ITU-T recommendation for data transmission * ATC code V04 ''Diagnostic agents'', a subgroup of the Anatomical Therapeutic Chemical Classification System * The V4 JavaScript engine for QML * V4, one of six precordial leads in electrocardiography Other uses * Visegrád Group, an alliance of four Central European states - Czech Republic, Hungary, Poland and Slovakia * ''Rheinbote'' or V-4, a German World War II four-stage missile * Saint Kitts & Nevis (ITU prefix) * Vieques Air Link (IATA airline code) * V4, a grade (climbing) In rock climbing, mountaineering, and other climbing disciplines, climbers give a grade to a climbing route or boulder problem, intended to describe concisely the difficulty and danger of climbing it. Different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LNER Class V4
The London and North Eastern Railway Class V4 was a class of 2-6-2 steam locomotive designed by Sir Nigel Gresley for mixed-traffic use. It was Gresley's last design for the LNER before he died in 1941. The V4s had similarities in their appearance and mechanical layout to the V2 "Green Arrow" class. The V2s, introduced some years before, were large and heavy locomotives, with very limited route availability. The V4 was a lightweight alternative, suitable for use over the whole of the LNER network. Features Two locomotives were built at the LNER's Doncaster Works in 1941. The first engine, 3401 ''Bantam Cock'', had a scaled-down version of the Gresley Pacific boiler with a grate area of 28.5 sq ft. Its tractive effort of 27,000 lbs was produced by boiler pressure of 250 psi and three cylinders of 15-inch diameter. The second locomotive, 3402, incorporated a fully welded steel firebox and a single thermic syphon for water circulation. It was not named, but was known unofficially a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V4 Engine
A V4 engine is a four-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration. The V4 engine is less common compared to straight-four engines. However, V4 engines have been used in automobiles, motorcycles, and other applications. Design Most V4 engines have two crankpins that are shared by opposing cylinders. The crankshaft is usually supported by three main bearings. Compared to the more common inline-four engine layout, a V4 engine is much shorter. Although different V angles can be used, if the two pistons are at a 90° V-angle with shared crankpins, the engine offers the additional advantage of perfect primary balance that reduces vibration. The design can also result in a smaller rocking couple than an inline-four engine, and the shorter crankshaft is less susceptible to the effects of torsional vibration due to its increased stiffness. Disadvantages of V4 engines include its design being inherently wider compared to in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Area V4
The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. The area of the visual cortex that receives the sensory input from the lateral geniculate nucleus is the primary visual cortex, also known as visual area 1 ( V1), Brodmann area 17, or the striate cortex. The extrastriate areas consist of visual areas 2, 3, 4, and 5 (also known as V2, V3, V4, and V5, or Brodmann area 18 and all Brodmann area 19). Both hemispheres of the brain include a visual cortex; the visual cortex in the left hemisphere receives signals from the right visual field, and the visual cortex in the right hemisphere receives signals from the left visual field. Introduction The primary visual cortex (V1) is located in and around the calcarine fissure in the occipital lobe. Each hemisphere's V1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klein Four-group
In mathematics, the Klein four-group is a Group (mathematics), group with four elements, in which each element is Involution (mathematics), self-inverse (composing it with itself produces the identity) and in which composing any two of the three non-identity elements produces the third one. It can be described as the symmetry group of a non-square rectangle (with the three non-identity elements being horizontal and vertical reflection and 180-degree rotation), as the group of bitwise operation, bitwise exclusive or operations on two-bit binary values, or more abstract algebra, abstractly as , the Direct product of groups, direct product of two copies of the cyclic group of Order (group theory), order 2. It was named ''Vierergruppe'' (meaning four-group) by Felix Klein in 1884. It is also called the Klein group, and is often symbolized by the letter V or as K4. The Klein four-group, with four elements, is the smallest group that is not a cyclic group. There is only one other group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ITU-T V-Series Recommendations
The ITU-T V-Series Recommendations on Data communication over the telephone network specify the protocols that govern approved modem communication standards and interfaces. ''Note:'' the '' bis'' and ''ter'' suffixes are ITU-T standard designators of successive iterations of a standard (''bis'' and ''ter'' are derived from the Latin for "twice" and "thrice"). General standards ''Applies to V.1–V.9'' *V.1 is an ITU-T recommendation, entitled ''Equivalence between binary notation symbols and the significant conditions of a two-condition code.'' *V.2 is an ITU-T recommendation, approved in November 1988, titled ''Power levels for data transmission over telephone lines.'' *V.4 is an ITU-T recommendation, approved in November 1988, titled ''General structure of signals of International Alphabet No. 5 code for character oriented data transmission over public telephone networks.'' *V.5 was an ITU-T recommendation, approved in November 1988, titled ''Standardization of data signall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ATC Code V04
V04B Urine tests :''Empty group'' V04C Other diagnostic agents V04CA Tests for diabetes :V04CA01 Tolbutamide :V04CA02 Glucose V04CB Tests for fat absorption :V04CB01 Vitamin A concentrates V04CC Tests for bile duct patency :V04CC01 Sorbitol :V04CC02 Magnesium sulfate :V04CC03 Sincalide :V04CC04 Ceruletide V04CD Tests for pituitary function :V04CD01 Metyrapone :V04CD03 Sermorelin :V04CD04 Corticorelin :V04CD05 Somatorelin :V04CD06 Macimorelin V04CE Tests for liver functional capacity :V04CE01 Galactose :V04CE02 Sulfobromophthalein :V04CE03 Methacetin (13C) V04CF Tuberculosis diagnostics :V04CF01 Tuberculin V04CG Tests for gastric secretion :V04CG01 Cation exchange resins :V04CG02 Betazole :V04CG03 Histamine phosphate :V04CG04 Pentagastrin :V04CG05 Methylthioninium chloride :V04CG30 Caffeine and sodium benzoate V04CH Tests for renal function and ureteral injuries :V04CH01 Inulin and other polyfructosans :V04CH02 Indigo carmine :V04CH03 Phenolsulfonphthalein :V04CH0 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JavaScript
JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of Website, websites use JavaScript on the Client (computing), client side for Web page, webpage behavior, often incorporating third-party Library (computing), libraries. All major Web browser, web browsers have a dedicated JavaScript engine to execute the Source code, code on User (computing), users' devices. JavaScript is a High-level programming language, high-level, often Just-in-time compilation, just-in-time compiled language that conforms to the ECMAScript standard. It has dynamic typing, Prototype-based programming, prototype-based object-oriented programming, object-orientation, and first-class functions. It is Programming paradigm, multi-paradigm, supporting Event-driven programming, event-driven, functional programming, functional, and imperative programming, imperative programming paradigm, programmin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocardiography
Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin. These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). Changes in the normal ECG pattern occur in numerous cardiac abnormalities, including cardiac rhythm disturbances (such as atrial fibrillation and ventricular tachycardia), inadequate coronary artery blood flow (such as myocardial ischemia and myocardial infarction), and electrolyte disturbances (such as hypokalemia and hyperkalemia). Traditionally, "ECG" usually means a 12-lead ECG taken while lying down as discussed below. However, other devices can record the electrical activity of the heart such as a Holter monitor but also s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visegrád Group
The Visegrád Group (also known as the Visegrád Four, the V4, or the European Quartet) is a cultural and political alliance of four Central European countries: the Czech Republic, Hungary, Poland, and Slovakia. The alliance aims to advance co-operation in military, economic, cultural and energy affairs, and to further their integration with the EU. All four states are also members of the European Union (EU) and the North Atlantic Treaty Organization (NATO). The alliance traces its origins to the summit meetings of leaders of Czechoslovakia, Hungary and Poland, held in the Hungarian castle town of Visegrád on 15 February 1991. Visegrád was chosen as the location for the summits as an intentional allusion to the medieval Congress of Visegrád between John I of Bohemia, Charles I of Hungary, and Casimir III of Poland in 1335. After the dissolution of Czechoslovakia in 1993, the Czech Republic and Slovakia became independent members of the alliance, incrementing the number of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheinbote
''Rheinbote'' (''Rhine Messenger'', or V4) was a German short range ballistic rocket developed by Rheinmetall-Borsig at Berlin-Marienfelde during World War II. It was intended to replace, or at least supplement, large-bore artillery by providing fire support at long ranges in an easily transportable form. History One of the problems for the German military, and indeed any mobile military force, is the weight of the artillery and, more importantly, its ammunition supply. Battlefield rockets were intended to circumvent the problems, which led to the development of ''Rheinbote''. The ''Rheinbote'' was the successor of the earlier ''Rheintochter'' (Rhine Maiden). Developed in 1943 by the Rheinmetall-Borsig company, ''Rheinbote'' was a four-stage solid-fuelled rocket, and the only long-range battlefield ballistic missile to enter service in World War II. The first test flights were carried out that year. Several changes were made to the system, but the basic design remained the same. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Kitts & Nevis
Saint Kitts and Nevis (), officially the Federation of Saint Christopher and Nevis, is an island country and microstate consisting of the two islands of Saint Kitts and Nevis, both located in the West Indies, in the Leeward Islands chain of the Lesser Antilles. With 261 square kilometers of territory, and roughly 50,000 inhabitants, it is the smallest sovereign state in the Western Hemisphere, in both area and population, as well as the world's smallest sovereign federation. The country is a Commonwealth realm, with Charles III as King and head of state. It is the only sovereign federation in the Caribbean. The capital city is Basseterre, located on the larger island of Saint Kitts. Basseterre is also the main port for passenger entry (via cruise ships) and cargo. The smaller island of Nevis lies approximately to the southeast of Saint Kitts, across a shallow channel called The Narrows. The British dependency of Anguilla was historically also a part of this union, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vieques Air Link
Vieques Air Link (VAL, IATA code:V4) is a small Puerto Rico-based airline that links Vieques with Culebra and mainland Puerto Rico. History Operations began during 1965, with owner Osvaldo "Val" Gonzalez-Duriex piloting a plane with three passengers from Vieques to Humacao. A Cherokee aircraft and another airplane were also acquired later, allowing the airline to serve Isla Verde International Airport. In 1968, Vieques Air Link added a flight to St. Croix in the Virgin Islands. In 1980 Fajardo Airport in Fajardo was built and Vieques Air Link started flights to the new airport immediately. In the 1980s the company increased the frequency of flights to San Juan, Humacao and Culebra. In 1989, Vieques Air Link lost its entire fleet to Hurricane Hugo. However, it soon acquired seven Britten-Norman Islanders and three Trislanders. In the 1990s VAL got into financial trouble. However, with the Vieques conflict, more and more Puerto Ricans began flying Vieques Air Link ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
