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4529e5c9d3b28bf8a831207131996919 | https://www.britannica.com/technology/radar/Advances-during-World-War-II | Advances during World War II | Advances during World War II
The opening of higher frequencies (those of the microwave region) to radar, with its attendant advantages, came about in late 1939 when the cavity magnetron oscillator was invented by British physicists at the University of Birmingham. In 1940 the British generously disclosed to the United ... |
7ed55bd76256e311200739623c811402 | https://www.britannica.com/technology/radial-tire | Radial tire | Radial tire
A radial-ply belted tire also has a belt running around the entire tire, but the cords are typically made of steel wire-mesh, hence the term “steel-belted radial” tire.
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0422214ff37ff9a921d2c085bcb9b538 | https://www.britannica.com/technology/radiation-measurement/Passive-detectors | Passive detectors | Passive detectors
The use of photographic techniques to record ionizing radiations dates back to the discovery of X rays by Röntgen in the late 1800s, but similar techniques remain important today in some applications. A photographic emulsion consists of a suspension of silver halide grains in an inert gelatin matrix a... |
4830ec2ea95e50ac004cce323df98466 | https://www.britannica.com/technology/radio-technology | Radio technology | Radio technology
Radio technology, transmission and detection of communication signals consisting of electromagnetic waves that travel through the air in a straight line or by reflection from the ionosphere or from a communications satellite.
Electromagnetic radiation includes light as well as radio waves, and the two... |
2d73c361273f5c9bc0f596fac01404d0 | https://www.britannica.com/technology/radiometer | Radiometer | Radiometer
Radiometer, instrument for detecting or measuring radiant energy. The term is applied in particular to devices used to measure infrared radiation. Radiometers are of various types that differ in their method of measurement or detection. Those that function by means of an increase in the temperature of the ... |
dcafc54452f667e1a2a8267fb2c4c29e | https://www.britannica.com/technology/radius-gauge | Radius gauge | Radius gauge
…the most common types are radius gauges, which are packs of blades with both concave and convex circular profiles that are used to check the radii of grooves and corners, and screw-thread pitch gauges, which are blades with triangular serrations spaced to correspond with various pitches, or numbers of thr... |
e4f2bd35b95c20eb46313f0369a262f5 | https://www.britannica.com/technology/raeda | Raeda | Raeda
A four-wheeled raeda in its passenger version corresponded to the stagecoaches of a later period and in its cargo version to the freight wagons. Fast freight raedae were drawn by 8 horses in summer and 10 in winter and, by law, could not haul in excess of…
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56f7831a9a6a97657df625e1fc32f61f | https://www.britannica.com/technology/railroad-track | Railroad track | Railroad track
Ideally, a railroad should be built in a straight line, over level ground, between large centres of trade and travel. In practice, this ideal is rarely approached. The location engineer, faced with the terrain to be traversed, must…
…and other mining areas such railroads or plateways were widespread befo... |
bd026cdfeeebc1d28d75b2a9a02e3627 | https://www.britannica.com/technology/railroad/Canadian-railroads | Canadian railroads | Canadian railroads
In its earliest years Canadian railroading was influenced by British rail practice, but after a decade of experience with North American economic and geographic realities, American practice began a fairly rapid rise to dominance that has remained to the present. The first transborder line was complet... |
3d4a8f093ed2ed9a39244ad4b630a8d4 | https://www.britannica.com/technology/rapier-loom | Rapier loom | Rapier loom
Rapier loom, a shuttleless weaving loom in which the filling yarn is carried through the shed of warp yarns to the other side of the loom by fingerlike carriers called rapiers. One type has a single long rapier that reaches across the loom’s width to carry the filling to the other side. Another type has t... |
3fc88cd46ca5b80896e9eadf6762ba0c | https://www.britannica.com/technology/rapier-sword | Rapier | Rapier
…his weapon, and the thrust-and-parry rapier came into use.
The long rapier was beautifully balanced, excellent in attack, and superb for keeping an opponent at a distance, but it was too heavy for all the movements of combat. Defense when fighting with a rapier was effected by parrying with the left hand, which... |
05d9f58291c54aebe5d08695b76a2113 | https://www.britannica.com/technology/rasp | Rasp | Rasp
Rasp teeth are disconnected and round on top; they are formed by raising small pieces of material from the surface of the file with a punch. Rasp files, or rasps, are usually very coarse and are used primarily on wood and soft materials.
Rasps, or, more correctly, rasp-cut files, have a series of individual teeth ... |
693309437345b490db2bf8b9c036c2f0 | https://www.britannica.com/technology/ratchet | Ratchet | Ratchet
Ratchet, mechanical device that transmits intermittent rotary motion or permits a shaft to rotate in one direction but not in the opposite one. In the Figure the arm A and the ratchet wheel B are both pivoted at O. The stem of the pawl P can slide in the arm and is kept in its lowest position by the spring S.... |
624ea093b0ad0797280a1abe29d2a198 | https://www.britannica.com/technology/RB211 | RB211 | RB211
…new, powerful jet engine, the RB211. In order to beat its competitor General Electric, the company agreed to a fixed-price contract with Lockheed Aircraft Corporation (see Lockheed Martin Corporation) to supply the RB211 turbofan for Lockheed’s L-1011 TriStar wide-body airliner. Rolls-Royce management made sever... |
7ce8973377507f0be1fe4b3e0b2cc7a3 | https://www.britannica.com/technology/reactance | Reactance | Reactance
Reactance, in electricity, measure of the opposition that a circuit or a part of a circuit presents to electric current insofar as the current is varying or alternating. Steady electric currents flowing along conductors in one direction undergo opposition called electrical resistance, but no reactance. Reac... |
f69ed59bf089960160681c84890285a7 | https://www.britannica.com/technology/reactive-ion-etching | Reactive ion etching | Reactive ion etching
…with strong chemicals or by reactive ion etching (RIE). RIE is like sputtering in the argon chamber, but the polarity is reversed and different gas mixtures are used. The atoms on the surface of the wafer fly away, leaving it bare.
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1bdabbeb2deb1641abcc53277b6f6cab | https://www.britannica.com/technology/reactive-liquid-sintering | Reactive-liquid sintering | Reactive-liquid sintering
In reactive-liquid, or transient-liquid, sintering, a chemical additive produces a temporary liquid that facilitates the initial stages of sintering. The liquid is subsequently evaporated, resorbed by the solid particles, or crystallized into a solid.
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58e112a0a89a73bf81c4ef7337cd2f16 | https://www.britannica.com/technology/reflector-nuclear-reactor | Reflector | Reflector
A reflector is a region of unfueled material surrounding the core. Its function is to scatter neutrons that leak from the core, thereby returning some of them back into the core. This design feature allows for a smaller core size. In addition, reflectors “smooth…
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9dfad09ec01ac5fd316c57f4e36904f9 | https://www.britannica.com/technology/reflex-camera | Reflex camera | Reflex camera
Most cameras now use the reflex system for viewing and focusing; in this system a mirror diverts to the viewfinder some of the light rays coming through the lens. Zoom lenses are commonly used on many cameras, as are ordinary wide-angle and telephoto lenses. The shutter is located behind the…
…used today ... |
8428b500b3c33d07b10144b14523514f | https://www.britannica.com/technology/refrigerant | Refrigerant | Refrigerant
These inorganic uses, as a flux and in the manufacture of aluminum, formerly constituted almost the whole of the fluorine industry. The organic fluorine industry, a separate branch, began in the late 1920s with the discovery by Thomas Midgley, Jr., of the United States,…
The development of highly efficient ... |
7a8d2077a55e179ccae955afd81e9b6b | https://www.britannica.com/technology/refrigeration | Refrigeration | Refrigeration
Refrigeration, the process of removing heat from an enclosed space or from a substance for the purpose of lowering the temperature.
In the industrialized nations and affluent regions in the developing world, refrigeration is chiefly used to store foodstuffs at low temperatures, thus inhibiting the destru... |
290d9a0b774e7b61d5abf2157e7c0939 | https://www.britannica.com/technology/regulating-rod | Regulating rod | Regulating rod
Regulating rods are deliberately designed to affect reactivity only by a small degree. It is assumed that at some time the rods might be totally withdrawn by mistake, and the idea is to keep the added reactivity in such cases well within sensible limits. A…
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b4adb5ae09956bf259d26a3f4c92edd2 | https://www.britannica.com/technology/regulatory-sign | Regulatory sign | Regulatory sign
They are classified as regulatory signs, which provide notice of traffic laws and regulations (e.g., signs for speed limits and for stop, yield or give-way, and no entry); warning signs, which call attention to hazardous conditions (e.g., sharp curves, steep grades, low vertical clearances, and slippery... |
2726c4ad0fa96de07e0deae07e7e4f4c | https://www.britannica.com/technology/Regulus-II | Regulus II | Regulus II
A follow-on design, Regulus II, was pursued briefly, striving for supersonic speed. However, the navy’s preference for the new large, angle-deck nuclear aircraft carriers and for ballistic missile submarines relegated sea-launched cruise missiles to relative obscurity. Another project, the Triton, was simila... |
f58d93f88a30b01f89fd5a91e5eadabd | https://www.britannica.com/technology/Regulus-missile | Regulus | Regulus
The Regulus, which was closely akin to the Matador (having the same engine and roughly the same configuration), became operational in 1955 as a subsonic missile launched from both submarines and surface vessels, carrying a 3.8-megaton warhead. Decommissioned in 1959, the Regulus did not represent much…
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77ab9a60c1abe2e44f494672d76a9e48 | https://www.britannica.com/technology/reheat-turbine | Reheat turbine | Reheat turbine
…(2) increasing turbine output by reheating after partial expansion, or (3) decreasing fuel consumption by regeneration.
If high-pressure, high-temperature steam is partially expanded through a turbine, the efficiency can be increased by returning the steam to the steam generator and reheating it to appr... |
8d5946167b9dad123b19ebac3a07e533 | https://www.britannica.com/technology/Reims-Racer | Reims Racer | Reims Racer
Hamilton to demonstrate Curtiss’s prizewinning Reims Racer in the early months of 1910, until Hamilton crashed and destroyed the machine (Hamilton was known to dive from an altitude of some 190 feet [60 metres], leveling out only when he reached 5 feet [1.5 metres] above the ground).
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89573daf51c08d4e1a7ee8112cb6d1b4 | https://www.britannica.com/technology/Remendur | Remendur | Remendur
…a magnetic alloy known as Remendur is added to two sides of the reed relay. When the coil is energized, the Remendur material retains the magnetism and polarity, thus acting as a switch with a memory. In addition to this new switch device, the No. 1 ESS incorporated a new…
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b1d147f5e3a6daadc1dfd1631ad0f5e3 | https://www.britannica.com/technology/Remington | Remington Typewriter | Remington Typewriter
Remington and Sons, gunsmiths, of Ilion, New York, for manufacture. The first typewriters were placed on the market in 1874, and the machine was soon renamed the Remington. Among its original features that were still standard in machines built a century later were the cylinder,…
…machine being mark... |
f180b732f268f4d98697962ea62a7dab | https://www.britannica.com/technology/Remington-Rolling-Block-Rifle | Remington Rolling Block Rifle | Remington Rolling Block Rifle
-made Remington Rolling Block Rifle, in which the breechblock was cocked back on a hinge like the hammer, was bought by a number of countries around the world. The United States itself adopted a series of single-shot rifles employing a hinged-breech “trap-door” mechanism, developed by Ersk... |
6110d88e65a9ecdbff4300d13d798997 | https://www.britannica.com/technology/remote-pier-terminal | Remote-pier terminal | Remote-pier terminal
The remote pier was introduced at Atlanta’s Hartsfield in the early 1980s. In this concept, passengers are brought out to a remote pier by an automatic people mover and there embark or disembark in the conventional manner. The system has proved very…
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c53e2c24e3b9d4fc21c212aa061a2845 | https://www.britannica.com/technology/repeating-rifle | Repeating rifle | Repeating rifle
Repeating rifle, also called repeater, rifled shoulder arm typically designed with a spring-loaded tubular or box magazine holding metallic cartridges, each of which is fed into the chamber or breech by a lever, pump, bolt, or semiautomatic mechanism. Before the invention of the self-contained cartridg... |
a210aacaf3d597655677991e22cbe921 | https://www.britannica.com/technology/required-freight-rate | Required freight rate | Required freight rate
…often referred to as the required freight rate. Actual freight rates are set by market conditions and inevitably fluctuate during the life of a ship.
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fa14c77508881150a5738742a41e142a | https://www.britannica.com/technology/resist-printing | Resist printing | Resist printing
Resist printing, any of various methods of colouring cloth in a pattern by pretreating designed areas to resist penetration by the dye. To obtain a two-colour pattern on goods already dyed in one colour, a dye paste is applied in the desired design; the paste contains a substance resistant to a second... |
a563cbb148a17af2a7dd05d79161be9d | https://www.britannica.com/technology/resonance-drive | Resonance drive | Resonance drive
…magnetic material, or (3) the resonance drive, in which a tiny tuning fork (about 25 mm [1 inch] in length), driven electrically, provides the motive power. Both galvanometer and induction drive types use a mechanical contact, actuated by the balance motion, to provide properly timed electric-drive pul... |
c45a536bfef10708e1a7b06aa104378c | https://www.britannica.com/technology/responsive-environments | Responsive environments | Responsive environments
Responsive environments, the use of sensory technology and computer equipment to create a collaborative relationship between objects in an environment and the movements of the human body. Similar to a computer mouse’s ability to allow interaction between a computer and its user, responsive envi... |
573de963f9a144b9699580e329188b3b | https://www.britannica.com/technology/retaining-wall | Retaining wall | Retaining wall
Retaining wall, also called revetment or breast wall, freestanding wall that either resists some weight on one side or prevents the erosion of an embankment. It may also be “battered”—that is, inclined toward the load it is bearing.
There are a number of methods employed to resist the lateral force agai... |
76e56012d32b618105743a766e9dbaf5 | https://www.britannica.com/technology/retort | Retort | Retort
Retort, vessel used for distillation of substances that are placed inside and subjected to heat. The simple form of retort, used in some laboratories, is a glass or metal bulb having a long, curved spout through which the distillate may pass to enter a receiving vessel. The design dates back to the cucurbit (f... |
37a8fb274f0ec22d10dba95eb1a807d0 | https://www.britannica.com/technology/rib-vault | Rib vault | Rib vault
…were made thinner by introducing ribs at the intersections of their curved surfaces, called groins. The ribs were built with supporting formwork or centring made of timber; close cooperation was needed between the carpenters and the masons. The curved surfaces of stones between the ribs were probably laid wi... |
98a7712739394c4b798b31026d550dba | https://www.britannica.com/technology/ricochet | Ricochet | Ricochet
Ricochet, in gunnery, rebound of a projectile that strikes a hard surface, or the rebounding projectile itself. At one time a form of fire known as ricochet was widely used; artillery was aimed to permit the shot to strike and rebound in a succession of skips. The invention of this type of fire in the late 17... |
1d8c52ea0858686bdba56f0495664c51 | https://www.britannica.com/technology/rifle | Rifle | Rifle
Rifle, firearm with a rifled bore—i.e., having shallow spiral grooves cut inside the barrel to impart a spin to the projectile, thus stabilizing it in flight. A rifled barrel imparts much greater accuracy to a projectile, as compared with a smoothbore barrel. The name rifle, most often applied to a weapon fired ... |
529056189c2099e9faeb694b0d3b34bf | https://www.britannica.com/technology/rifle-grenade | Rifle grenade | Rifle grenade
…from the muzzle of a rifle either by the force of a cartridge or by the expanding gases of a blank cartridge. Such grenades usually have long, streamlined bodies, in contrast to the round shapes of hand grenades. There are also small-arm grenade rounds, shaped like bullets but of much…
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042b6502bce310691098a46f76d53d7d | https://www.britannica.com/technology/rifling | Rifling | Rifling
As killing machines, smoothbore infantry muskets were relatively inefficient. Their heavy round lead balls delivered bone-crushing and tissue-destroying blows when they hit a human body, but beyond 75 yards even trained infantrymen found it difficult to hit an individual adversary. Volley fire against massed…
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918825fd6e5f870ec0d456755325b72a | https://www.britannica.com/technology/rigid-airship | Rigid airship | Rigid airship
nonrigids (blimps), semirigids, and rigids. All three types have four principal parts: a cigar-shaped bag, or balloon, that is filled with a lighter-than-air gas; a car or gondola that is slung beneath the balloon and holds the crew and passengers; engines that drive propellers; and horizontal and vertica... |
a8577520a1d04a3a95e34a387ffb5e4e | https://www.britannica.com/technology/riser-casting | Riser | Riser
Sometimes additional spaces, called risers, are added to the casting to provide reservoirs to feed this shrinkage. After solidification is complete, the sand is removed from the casting, and the gate is cut off. If cavities are intended to be left in the casting—for example, to form a hollow…
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99e7da58270e676cb43625b7b5bb20ed | https://www.britannica.com/technology/riser-staircase | Riser | Riser
… and the vertical front its riser; steps are placed between strings that are inclined to the angle of the staircase; strings are supported by newel posts that also support the handrail, forming a balustrade.
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f64818e92b1f01c3fe848ff854a8cc56 | https://www.britannica.com/technology/road-map | Road map | Road map
Road maps, produced by the millions, are compiled from road surveys, topographic maps, and aerial photography. City maps often represent original surveys, made principally to control engineering plans and construction. Some are, however, compiled from enlargements of topographic maps of the area.
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df522a4c9db1d0b29bd28d1a6f1935e0 | https://www.britannica.com/technology/road-sign | Road sign | Road sign
Signs advise the driver of special regulations and provide information about hazards and navigation. They are classified as regulatory signs, which provide notice of traffic laws and regulations (e.g., signs for speed limits and for stop, yield or give-way, and no entry); warning signs, which…
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b157cc141c4467beb64bd574c50b0ec7 | https://www.britannica.com/technology/road/The-modern-road | The modern road | The modern road
Since the beginning of the 20th century, as the automobile and truck have offered ever higher levels of mobility, vehicle ownership per head of population has increased. Road needs have been strongly influenced by this popularity and also by the mass movement of people to cities and thence to suburban f... |
69a43e410d449c3b0c120a6d90ee07e9 | https://www.britannica.com/technology/robotics | Robotics | Robotics
Robotics, design, construction, and use of machines (robots) to perform tasks done traditionally by human beings. Robots are widely used in such industries as automobile manufacture to perform simple repetitive tasks, and in industries where work must be performed in environments hazardous to humans. Many asp... |
eed47a1df4b10610f22aaf3f18e71cb9 | https://www.britannica.com/technology/rockaway | Rockaway | Rockaway
Rockaway, a light, low, four-wheeled, horse-drawn carriage popular in the United States after its introduction at Rockaway, N.J., in 1830. It had a driver’s seat built into the body, with the top projecting forward to protect the driver from inclement weather. The main body was of the coupé type and was susp... |
e11bcae4c4ad79e37e52ef4d4980a81e | https://www.britannica.com/technology/rocket-jet-propulsion-device-and-vehicle/Chemical-rockets | Chemical rockets | Chemical rockets
Rockets that employ chemical propellants come in different forms, but all share analogous basic components. These are (1) a combustion chamber where condensed-phase propellants are converted to hot gaseous reaction products, (2) a nozzle to accelerate the gas to high exhaust velocity, (3) propellant co... |
6acc281c5d1b5631df163ba4e5e3b583 | https://www.britannica.com/technology/roentgenogram | Roentgenogram | Roentgenogram
Roentgenogram, also called roentgenograph or X-ray image, photograph of internal structures that is made by passing X-rays through the body to produce a shadow image on specially sensitized film. The roentgenogram is named after German physicist Wilhelm Conrad Röntgen, who discovered X-rays in 1895. The ... |
591b35686cb2c75c22deafe886594100 | https://www.britannica.com/technology/roller-chain | Roller chain | Roller chain
A roller chain is a development of the block chain in which the block is replaced by two side plates, a pair of bushings, and rollers. (See Figure 3.) This type of chain is used on bicycles and is adaptable to many other needs, from small-strand…
Hans Renold invented the bush roller chain in Manchester, En... |
62925e460a19185a8065d837c1a6832c | https://www.britannica.com/technology/rood-screen | Rood screen | Rood screen
Rood screen, in Western architecture, element of a Christian church of the Middle Ages or early Renaissance that separated the choir or chancel (the area around the altar) from the nave (the area set apart for the laity). The rood screen was erected in association with the rood, which in Old English means ... |
5ebfb33bf491d7721b0d6dc52d5ac277 | https://www.britannica.com/technology/rowboat | Rowboat | Rowboat
Rowboat, boat propelled by oars alone, probably the most common type of boat found around waterfronts and at most fishing camps and docks on inland waters.
A true rowboat or sculling boat has an easy motion through the water and, most important, glides between strokes. Thus the boat’s forward motion never cea... |
37b623ead80da78429fe0f55c33f2d51 | https://www.britannica.com/technology/Rubis | Rubis | Rubis
…first nuclear attack submarine, the Rubis, was laid down in 1976 with antisubmarine torpedo and sonar systems inherited from the diesel-electric Agosta class. Beginning in 1984, the four vessels of this class were given improved sonar and silencing and were fitted with dive-launched Exocet antiship missiles. The... |
ee23ec9d44c35d9fa5ac7ab7882a8f54 | https://www.britannica.com/technology/rug-and-carpet/Turkey | Turkey | Turkey
After the 16th century, Turkish rugs either followed Persian designs—indeed, were possibly worked by immigrant Persians and Egyptians—or followed native traditions. The former, made on court looms, displayed exquisite cloud bands and feathery, tapering white leaves on grounds of pale rose relieved by blue and em... |
6f1022a4d7ee00c0ac6e0c73849d29e3 | https://www.britannica.com/technology/rustication | Rustication | Rustication
Rustication, in architecture, type of decorative masonry achieved by cutting back the edges of stones to a plane surface while leaving the central portion of the face either rough or projecting markedly. Rustication provides a rich and bold surface for exterior masonry walls.
Rusticated masonry is found as... |
89a021ab4984e98c39e483838e1d7a62 | https://www.britannica.com/technology/S-37 | S-37 | S-37
Its fifth-generation, multirole, all-weather S-37 Berkut air-superiority fighter, first flown in 1997, was equipped with state-of-the-art electronics, forward-swept wings, and thrust vector control. In competition with MiG for the international market, Sukhoy also continued to develop the lightweight Su-54 fighter... |
7c710b60606909986ded105ad17dfe41 | https://www.britannica.com/technology/saber | Sabre | Sabre
Sabre, also spelled saber, heavy military sword with a long cutting edge and, often, a curved blade. Most commonly a cavalry weapon, the sabre was derived from a Hungarian cavalry sword introduced from the Orient in the 18th century; also a light fencing weapon developed in Italy in the 19th century for duelling... |
7f30f9165152eba6068306e59d3278f7 | https://www.britannica.com/technology/Safari-browser | Safari | Safari
Apple’s Safari was released in 2003 as the default browser on Macintosh personal computers and later on iPhones (2007) and iPads (2010). Safari 2.0 (2005) was the first browser with a privacy mode, Private Browsing, in which the application would not save Web sites in its…
Apple’s Safari was released in 2003 as ... |
1c27a058bfeeaa16f6c7d11d650d011b | https://www.britannica.com/technology/safe-vault | Safe | Safe
…all burglary coverages is on safes. Often the loss in the form of damage to the safe itself from the use of explosives and other devices is as great as the loss of the money, jewelry, or securities it contains. Accordingly, the policy covers both types of claims. Another common…
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c26cd98d4e519839f8af60f0fa69e4ae | https://www.britannica.com/technology/sail-watercraft-part | Sail | Sail
Sail, an extent of fabric (such as canvas) by means of which wind is used to propel a ship through water.
The first sails were most likely animal skins that were used to harness wind power for rafts or boats consisting of a single log. The next probable step was the use of woven reed mats stretched between poles.... |
9f6938abc5472149138a61ee7f24bd9f | https://www.britannica.com/technology/sailplane | Sailplane | Sailplane
…lack the dynamic sophistication of sailplanes. These sophisticated unpowered craft have wings of unusually high aspect ratio (that is, a long wing span in proportion to wing width). Most sailplanes are towed to launch altitude, although some employ small, retractable auxiliary engines. They are able to use t... |
8df0e9a8ead0c61c4bc5889584cd52db | https://www.britannica.com/technology/saltbox | Saltbox | Saltbox
Saltbox, in architecture, type of residential building popular in colonial New England, having two stories in front and a single story in the rear and a double-sloped roof that is longer over the rear section.The original clapboard houses of the New England settlers were constructed around a great central chi... |
8f07d8546f3cbf282b3798de14b33dca | https://www.britannica.com/technology/samizdat | Samizdat | Samizdat
Samizdat, (from Russian sam, “self,” and izdatelstvo, “publishing”), literature secretly written, copied, and circulated in the former Soviet Union and usually critical of practices of the Soviet government.
Samizdat began appearing following Joseph Stalin’s death in 1953, largely as a revolt against official... |
437256220d1a993d1d31b85aa12577e9 | https://www.britannica.com/technology/sandwich-panel | Sandwich panel | Sandwich panel
Metal sandwich panels are also used for economy of material; two thin layers of metal are separated by a core of different material, often with a high U-value for insulating effect. The separation of the thin layers of strong metal greatly increases the overall stiffness of…
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cbafe9f006e7e87fceb0b9a15fd97685 | https://www.britannica.com/technology/sanitary-landfill | Sanitary landfill | Sanitary landfill
Sanitary landfill, method of controlled disposal of municipal solid waste (refuse) on land. The method was introduced in England in 1912 (where it is called controlled tipping). Waste is deposited in thin layers (up to 1 metre, or 3 feet) and promptly compacted by heavy machinery (e.g., bulldozers); ... |
06ac4c65d6331aa4f384b430fdf5de73 | https://www.britannica.com/technology/satellite-system | Satellite system | Satellite system
A telecommunications satellite is a sophisticated space-based cluster of radio repeaters, called transponders, that link terrestrial radio transmitters to terrestrial radio receivers through an uplink (a link from terrestrial transmitter to satellite receiver) and a downlink (a
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f0f544fbcd442ce5579cd40932c9c03b | https://www.britannica.com/technology/Savonius-rotor | Savonius rotor | Savonius rotor
Known as the Savonius rotor, it consists of semicircular blades that can be constructed from little more than the two sections of an oil drum, cut in half along its vertical axis and welded together with an offset from the axis to form an open S. An advanced…
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fe03a779b157e4e4710335b0ec0b3d4e | https://www.britannica.com/technology/scanning | Scanning | Scanning
The fourth determination in image analysis is the path over which the image structure is explored at the camera and reconstituted on the receiver screen. In standard television, the pattern is a series of parallel straight lines, each progressing from left to right, the…
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1656c770ce83456157fee8365acf2b42 | https://www.britannica.com/technology/scanning-receiver-ceilometer | Scanning-receiver ceilometer | Scanning-receiver ceilometer
The scanning-receiver ceilometer has its separate light transmitter fixed to direct its beam vertically. The receiver is stationed a known distance away. The parabolic collector of the receiver continuously scans up and down the vertical beam, searching for the point where the light interse... |
382e7b3b526350cd0d435a2b38033c0d | https://www.britannica.com/technology/scarp-fortification | Scarp | Scarp
As a practical matter the scarp, or main fortress wall, now protected from artillery fire by the glacis, was faced with brick or stone for ease of maintenance; the facing wall on the forward side of the ditch, called the counterscarp, was similarly faced. Next, a level, sunken space behind…
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861f5d4ae7cf00f8d70beb3cac46b587 | https://www.britannica.com/technology/Schmidt-vertical-field-balance | Schmidt vertical-field balance | Schmidt vertical-field balance
The Schmidt vertical-field balance, a relative magnetometer used in geophysical exploration, uses a horizontally balanced bar magnet equipped with mirror and knife edges.
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5ed88f375086bf8e53348cbaf73aba0d | https://www.britannica.com/technology/school-library | School library | School library
Where public libraries and schools are provided by the same education authority, the public library service may include a school department, which takes care of all routine procedures, including purchasing, processing with labels, and attaching book cards and protective covers; the books are…
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ab2b9da0bb765de94816488e46a3856d | https://www.britannica.com/technology/scraper-tool | Scraper tool | Scraper tool
…kinds of flakes, points and scrapers. The former are roughly triangular, with two trimmed or sharp edges meeting in a point, the base or butt of the triangle being thick and blunt. The side scrapers have a sharp edge in the long direction of the flake, with an opposite, thicker…
…that the Paleolithic unif... |
67b122e9c01cda5665c17eabab18a124 | https://www.britannica.com/technology/screw-type-extruder | Screw-type extruder | Screw-type extruder
In a commercial screw-type extruder, a screw auger continuously forces the plastic feed material through an orifice or die, resulting in simple shapes such as cylindrical rods and pipes, rectangular solid and hollow bars, and long plates. These shapes can be cut upon extrusion into shorter pieces fo... |
d47a98e2e60d540dd7c007e1213ace6c | https://www.britannica.com/technology/script-computer-science | Script | Script
…server contains small programs called scripts that take information from the browser system or provide it for display. A simple script might ask the reader’s name, determine the Internet address of the system that the reader uses, and print a greeting. Scripts may be written in any programming language, but,…
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995f597833f9965bec0401a62eedfbb4 | https://www.britannica.com/technology/scythe | Scythe | Scythe
Scythe, one of the most important of all agricultural hand tools, consisting of a curved blade fitted at an angle to a long, curved handle and used for cutting grain. In modern scythes the handle has a projecting peg that is grasped by one hand, facilitating control of the swinging motion by which grass and gr... |
8474152066743966aa39dd2e1389c39a | https://www.britannica.com/technology/sea-works | Sea works | Sea works
The construction of harbours and sea works offers some of the most unusual problems and challenges in civil engineering. The continuous and immediate presence of the sea provides the engineer with an adversary certain to discover any weakness in the structure built to resist it.
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11641aa138a1577f26ede3942ad0e589 | https://www.britannica.com/technology/search-engine | Search engine | Search engine
Search engine, computer program to find answers to queries in a collection of information, which might be a library catalog or a database but is most commonly the World Wide Web. A Web search engine produces a list of “pages”—computer files listed on the Web—that contain the terms in a query. Most search... |
4b5fd964d1b3dea6491c3d1470634085 | https://www.britannica.com/technology/sequence-programming | Sequence | Sequence
Sequence is the default control structure; instructions are executed one after another. They might, for example, carry out a series of arithmetic operations, assigning results to variables, to find the roots of a quadratic equation ax2 + bx + c = 0. The conditional IF-THEN…
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5b0ecf6b12a7c554a97476271b6dd317 | https://www.britannica.com/technology/service-vessel | Service vessel | Service vessel
The service ships are mostly tugs or towing vessels whose principal function is to provide propulsive power to other vessels. Most of them serve in harbours and inland waters, and, because the only significant weight they need carry is a propulsion plant and…
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97194b9928a0609c8492d91537ede0ff | https://www.britannica.com/technology/sewer | Sewer | Sewer
Sewer, conduit that carries wastewater from its source to a point of treatment and disposal. The wastewater may be domestic (sanitary) sewage, industrial sewage, storm runoff, or a mixture of the three. Large-diameter pipes or tunnels that carry a mixture of the three types of liquid wastes, called combined sewe... |
49964d7a87296d1d3d7acbf789e4d627 | https://www.britannica.com/technology/shaft-furnace | Shaft furnace | Shaft furnace
Stone-built shaft furnaces, on the other hand, relied on natural draft, although they too sometimes used tuyeres. In both cases, smelting involved creating a bed of red-hot charcoal to which iron ore mixed with more charcoal was added. Chemical reduction of the ore then occurred, but,…
…of firing equipmen... |
08da7a3278d1401fff76edf8015a4ab9 | https://www.britannica.com/technology/shaped-charge | Shaped charge | Shaped charge
…guns used the shaped or hollow charge shell, which was designed to explode on impact and channel the explosive energy forward, enhancing penetrating force. Recoilless rifles were also specially developed for use against tanks.
…grenade, which contains a special shaped-charge explosive that can pierce ev... |
ea8ff7b0df1369d2339682542eb8e98d | https://www.britannica.com/technology/sheet-metallurgy | Sheet | Sheet
Sheet forming, used since the 19th century by metallurgists, is now applied to the processing of thermoplastic composites. In a typical thermoforming process, the sheet stock, or preform, is heated in an oven. At the forming temperature, the sheet is transferred into a forming system,…
The term copper strip as di... |
82447af593e99c6e364ba7fedd11bd91 | https://www.britannica.com/technology/shell-ammunition | Shell | Shell
Shell, variously, an artillery projectile, a cartridge case, or a shotgun cartridge. The artillery shell was in use by the 15th century, at first as a simple container for metal or stone shot, which was dispersed by the bursting of the container after leaving the gun. Explosive shells came into use in the 16th ... |
8062af0969f752a1043c0daebd70ab42 | https://www.britannica.com/technology/shell-structure-building-construction | Shell structure | Shell structure
Shell structure, in building construction, a thin, curved plate structure shaped to transmit applied forces by compressive, tensile, and shear stresses that act in the plane of the surface. They are usually constructed of concrete reinforced with steel mesh (see shotcrete). Shell construction began in... |
57daea83087197d8d14e7c2274cf0150 | https://www.britannica.com/technology/sherardizing | Sherardizing | Sherardizing
Sherardizing, means of forming a uniform, corrosion-resistant coating of zinc on the surface of iron or steel objects. The process, practiced since about 1900, is named for its English inventor Sherard O. Cowper-Coles. The object is heated in a sealed container with finely divided zinc to a temperature b... |
ae6016fd071b373882d52be58e097dd0 | https://www.britannica.com/technology/SHF | SHF | SHF
…to extremely high frequency (SHF-EHF) bands are in the centimetre to millimetre wavelength range, which extends from 3 gigahertz to 300 gigahertz. Typical allocated bandwidths in the SHF band range from 30 megahertz to 300 megahertz—bandwidths that permit high-speed digital communications (up to 1 gigabit per seco... |
7a218809c5ad3a83423146a598050317 | https://www.britannica.com/technology/ship-of-the-line | Ship of the line | Ship of the line
Ship of the line, type of sailing warship that formed the backbone of the Western world’s great navies from the mid-17th century through the mid-19th century, when it gave way to the steam-powered battleship.
The ship of the line evolved from the galleon, a three- or four-masted vessel that had a high... |
adb6d25369884ce2d8f7b66eb1879db0 | https://www.britannica.com/technology/ship/Cargo-handling | Cargo handling | Cargo handling
A commercial ship is usually a link in a “trade route” between distant points. Goods flowing in the route must be transferred to and from the sea link; they must also be given care while aboard the ship, and in turn they must not be a hazard to the ship and its crew.
Ancient cargo handling consisted almo... |
b9a2abab8e0dff0e209c99b49431bda6 | https://www.britannica.com/technology/ship/Passenger-liners-in-the-20th-century | Passenger liners in the 20th century | Passenger liners in the 20th century
The upper limits of speed possible with piston-engined ships had been reached, and failure in the machinery was likely to cause severe damage to the engine. In 1894 Charles A. Parsons designed the yacht Turbinia, using a steam turbine engine with only rotating parts in place of reci... |
c7c00b0bef678a219407a5d6a0d17568 | https://www.britannica.com/technology/ship/The-Atlantic-Ferry | “The Atlantic Ferry” | “The Atlantic Ferry”
At this point the contributions of Isambard Kingdom Brunel to sea transportation began. Brunel was the chief engineer of the Great Western Railway between Bristol and London, which was nearing completion in the late 1830s. A man who thrived on challenges, Brunel could see no reason his company shou... |
abd1440714829772ba39b121317ed99a | https://www.britannica.com/technology/shipping-route | Shipping route | Shipping route
Shipping route, any of the lines of travel followed by merchant sea vessels. Early routes usually kept within sight of coastal landmarks, but, as navigators learned to determine latitude from the heavenly bodies, they ventured onto the high seas more freely. When exact positions could be fixed, the eff... |
43d661111ecefdafd1a30fb7f2a40bc0 | https://www.britannica.com/technology/shock-weapon | Shock weapon | Shock weapon
A weapon may be a shock weapon, held in the hands, such as the club, mace, or sword. It may also be a missile weapon, operated by muscle power (as with the javelin, sling, and bow and arrow), mechanical power (as with the crossbow and catapult), or chemical power (as…
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79ddf0c0518334a7a14671c13ea8186a | https://www.britannica.com/technology/shotgun-house | Shotgun house | Shotgun house
Shotgun house, narrow house prevalent in African American communities in New Orleans and other areas of the southern United States, although the term has come to be used for such houses regardless of location. Shotgun houses generally consist of a gabled front porch and two or more rooms laid out in a st... |
fa16ed44f1d697aa5ebfaf544c015e4a | https://www.britannica.com/technology/signal-line | Signal line | Signal line
Herring fishermen used signal lines to find their prey in deep waters. These were long wires dropped from a boat; the fisherman holding the line in his hand could feel the vibration caused by the fish touching the line, which was named the herring’s telephone. Other fish were…
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