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George Constantinescu
George "Gogu" Constantinescu (; last name also Constantinesco; 4 October 1881 – 11 December 1965) was a Romanian scientist, engineer and inventor. During his career, he registered over 130 inventions. He is the creator of the ''theory of sonics'', a new branch of continuum mechanics, in which he described the transmission of mechanical energy through vibrations. Biography Early years Born in Craiova in "the Doctor's House" near the Mihai Bravu Gardens, he was influenced by his father George, born in 1844 (a professor of mathematics and engineering science, specialized in mathematics at the Sorbonne University). Gogu Constantinescu settled in the United Kingdom in 1912. He was an honorary member of the Romanian Academy. Family He married Alexandra (Sandra) Cocorescu in Richmond, London, in December 1914. The couple moved to Wembley and, after their son Ian was born, they moved to Weybridge. The marriage broke down in the 1920s and ended in divorce. He then married Ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craiova
Craiova (, also , ), is Romania's 6th Cities in Romania, largest city and capital of Dolj County, and situated near the east bank of the river Jiu River, Jiu in central Oltenia. It is a longstanding political center, and is located at approximately equal distances from the Southern Carpathians (north) and the Danube, River Danube (south). Craiova is the chief commercial city west of Bucharest and the most important city of Oltenia. The city prospered as a regional trading centre despite an earthquake in 1790, a plague in 1795, and a Ottoman Empire, Turkish assault in 1802 during which it was burned. Eight villages are administered by the city: Făcăi, Mofleni, Popoveni, Șimnicu de Jos, Cernele, Cernelele de Sus, Izvoru Rece, and Rovine. The last four were a separate commune called ''Cernele'' until 1996, when they were merged into the city. Etymology and names There are two possible etymologies for Craiova: Common Slavonic, Old Slavonic ''wikt:kral, kral'' ("king"), which has be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronization Gear
A synchronization gear (also known as a gun synchronizer or interrupter gear) was a device enabling a single-engine tractor configuration aircraft to fire its forward-firing armament through the arc of its spinning propeller without bullets striking the blades. This allowed the aircraft, rather than the gun, to be aimed at the target. There were many practical problems, mostly arising from the inherently imprecise nature of an automatic gun's firing, the great (and varying) velocity of the blades of a spinning propeller, and the very high speed at which any gear synchronizing the two had to operate. In practice, all known gears worked on the principle of actively triggering each shot, in the manner of a semi-automatic weapon. Design and experimentation with gun synchronization had been underway in France and Germany in 1913–1914, following the ideas of August Euler, who seems to have been the first to suggest mounting a fixed armament firing in the direction of flight (in 191 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Diesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of the fuel is une ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carburetor
A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main metering circuit, however various other components are also used to provide extra fuel or air in specific circumstances. Since the 1990s, carburetors have been largely replaced by fuel injection for cars and trucks, however carburetors are still used by some small engines (e.g. lawnmowers, generators and concrete mixers) and motorcycles. Diesel engines have always used fuel injection instead of carburetors. Etymology The name "carburetor" is derived from the verb ''carburet'', which means "to combine with carbon," or in particular, "to enrich a gas by combining it with carbon or hydrocarbons." Thus a carburetor mixes intake air with hydrocarbon-based fuel, such as petrol or autogas (LPG). The name is spelled "carburetor" in American English ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drifter (drill)
A drifter drill, sometimes called a rock drill, is a tool used in mining and civil engineering to drill into rock. Rock drills are used for making holes for placing dynamite or other explosives in rock blasting, and holes for plug and feather quarrying. While a rock drill may be as simple as a specialized form of chisel, it may also take the form of a powered machine. The mechanism may be worked or powered by hand, by steam, by compressed air (pneumatics), by hydraulics, or by electricity. Machine rock drills come in two basic forms: those that operate by percussion (using a reciprocating motion), and those that are abrasive (using a rotary motion). A smaller, hand-held percussion rock drill is considered a type of jackhammer. History and types The simplest form of rock drill consists of a long chisel or drill steel that was struck with a sledgehammer. Mark Twain, who worked unsuccessfully as a silver miner in the early 1860s before taking up journalism, described the proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave
In physics, mathematics, and related fields, a wave is a propagating dynamic disturbance (change from equilibrium) of one or more quantities. Waves can be periodic, in which case those quantities oscillate repeatedly about an equilibrium (resting) value at some frequency. When the entire waveform moves in one direction, it is said to be a ''traveling wave''; by contrast, a pair of superimposed periodic waves traveling in opposite directions makes a '' standing wave''. In a standing wave, the amplitude of vibration has nulls at some positions where the wave amplitude appears smaller or even zero. Waves are often described by a ''wave equation'' (standing wave field of two opposite waves) or a one-way wave equation for single wave propagation in a defined direction. Two types of waves are most commonly studied in classical physics. In a ''mechanical wave'', stress and strain fields oscillate about a mechanical equilibrium. A mechanical wave is a local deformation (strain) in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressibility
In thermodynamics and fluid mechanics, the compressibility (also known as the coefficient of compressibility or, if the temperature is held constant, the isothermal compressibility) is a measure of the instantaneous relative volume change of a fluid or solid as a response to a pressure (or mean stress) change. In its simple form, the compressibility \kappa (denoted in some fields) may be expressed as :\beta =-\frac\frac, where is volume and is pressure. The choice to define compressibility as the negative of the fraction makes compressibility positive in the (usual) case that an increase in pressure induces a reduction in volume. The reciprocal of compressibility at fixed temperature is called the isothermal bulk modulus. Definition The specification above is incomplete, because for any object or system the magnitude of the compressibility depends strongly on whether the process is isentropic or isothermal. Accordingly, isothermal compressibility is defined: :\beta_T=-\frac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrostatics
Fluid statics or hydrostatics is the branch of fluid mechanics that studies the condition of the equilibrium of a floating body and submerged body " fluids at hydrostatic equilibrium and the pressure in a fluid, or exerted by a fluid, on an immersed body". It encompasses the study of the conditions under which fluids are at rest in stable equilibrium as opposed to fluid dynamics, the study of fluids in motion. Hydrostatics is a subcategory of fluid statics, which is the study of all fluids, both compressible or incompressible, at rest. Hydrostatics is fundamental to hydraulics, the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics (for example, in understanding plate tectonics and the anomalies of the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields. Hydrostatics offers physical explanations for many phenomena of everyday life, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gloster Gladiator
The Gloster Gladiator is a British biplane fighter. It was used by the Royal Air Force (RAF) and the Fleet Air Arm (FAA) (as the Sea Gladiator variant) and was exported to a number of other air forces during the late 1930s. Developed privately as the Gloster SS.37, it was the RAF's last biplane fighter aircraft, and was rendered obsolete by newer monoplane designs even as it was being introduced. Though often pitted against more formidable foes during the early days of the Second World War, it acquitted itself reasonably well in combat. The Gladiator saw action in almost all theatres during the Second World War, with a large number of air forces, some of them on the Axis side. The RAF used it in France, Norway, Greece, the defence of Malta, the Middle East, and the brief Anglo-Iraqi War (during which the Royal Iraqi Air Force was similarly equipped). Other countries deploying the Gladiator included China against Japan, beginning in 1938; Finland (along with Swedish voluntee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) and the Royal Naval Air Service (RNAS). Following the Allied victory over the Central Powers in 1918, the RAF emerged as the largest air force in the world at the time. Since its formation, the RAF has taken a significant role in British military history. In particular, it played a large part in the Second World War where it fought its most famous campaign, the Battle of Britain. The RAF's mission is to support the objectives of the British Ministry of Defence (MOD), which are to "provide the capabilities needed to ensure the security and defence of the United Kingdom and overseas territories, including against terrorism; to support the Government's foreign policy objectives particularly in promoting international peace and security". The R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
