You're using an outdated browser. Please upgrade to a modern browser for the best experience.
Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort by:
Most Viewed Latest Alphabetical (A-Z) Alphabetical (Z-A)
Filter:
All Topic Review Biography Peer Reviewed Entry Video Entry
Topic Review
Dhunge Dhara
A dhunge dhara (Nepali:ढुङ्गे धारा Listen (help·info)) or hiti (Newari) is a traditional stone drinking fountain found in Nepal. It is an intricately carved stone waterway through which water flows uninterrupted from underground sources. Dhunge dharas are part of a comprehensive drinking water supply system, commissioned by various rulers of Ancient and Medieval Nepal. The system is supported by numerous ponds and canals that form an elaborate network of water bodies, created as a water resource during the dry season and to help alleviate the water pressure caused by the monsoon rains. After the introduction of modern, piped water systems, starting in the late 19th century, this old system has fallen into disrepair and some parts of it are lost forever. Nevertheless, many people of Nepal still rely on the old hitis on a daily basis.
  • 7.1K
  • 21 Oct 2022
Topic Review
Electromagnetic Aircraft Launch System
The Electromagnetic Aircraft Launch System (EMALS) is a type of aircraft launching system developed by General Atomics for the United States Navy. The system launches carrier-based aircraft by means of a catapult employing a linear induction motor rather than the conventional steam piston. EMALS was first installed on the United States Navy's Gerald R. Ford-class aircraft carrier, USS Gerald R. Ford. Its main advantage is that it accelerates aircraft more smoothly, putting less stress on their airframes. Compared to steam catapults, the EMALS also weighs less, is expected to cost less and require less maintenance, and can launch both heavier and lighter aircraft than a steam piston-driven system. It also reduces the carrier's requirement of fresh water, thus reducing the demand for energy-intensive desalination. China is reportedly developing a similar system which is expected to be used on China's Type 003 aircraft carriers.
  • 7.0K
  • 21 Nov 2022
Topic Review
AK-630
The AK-630 is a Soviet and Russian fully automatic naval close-in weapon system based on a six-barreled 30 mm rotary cannon. In "630", "6" means 6 barrels and "30" means 30 mm. It is mounted in an enclosed automatic turret and directed by MR-123 radar and television detection and tracking. The system's primary purpose is defense against anti-ship missiles and other precision guided weapons. However it can also be employed against fixed or rotary wing aircraft, ships and other small craft, coastal targets, and floating mines. Once operational, this weapon system was rapidly adopted, with up to 8 units installed in every new Soviet warship (from mine-hunters to aircraft carriers), and hundreds produced in total.
  • 6.9K
  • 08 Oct 2022
Topic Review
List of Intel Pentium Microprocessors
The Intel Pentium brand refers to mainstream x86-architecture microprocessors from Intel. Processors branded Pentium Processor with MMX Technology (and referred to as Pentium MMX for brevity) are also listed here.
  • 6.7K
  • 26 Oct 2022
Topic Review
Heaviest Trains
The heaviest trains in the world are freight trains hauling bulk commodities such as coal and iron ore. The weight of trains generally does not include the weight of the operating locomotives; this is not considered dead weight, so is not included. If for example a train had two locomotives operating and was simply hauling a third off line, this third locomotive would be included in the payload weight.
  • 6.7K
  • 01 Nov 2022
Topic Review
Weapons of the Cambodian–Vietnamese War
This article is about the weapons used in the Cambodian–Vietnamese War, involved the Vietnam (Army: People's Army of Vietnam (PAVN)), People's Republic of Kampuchea (Army: Kampuchean People's Revolutionary Armed Forces (KPRAF)) which of the Khmer Rouge (Army:Kampuchean Revolutionary Army), Khmer People's National Liberation Front (Army: Khmer People's National Liberation Armed Forces), FUNCINPEC and Thailand (Army: Royal Thai Armed Forces (Thai: กองทัพไทย; RTGS: Kong Thap Thai)) (border clashes) From Vietnam and People's Republic of Kampuchea supported by Soviet Union and other country socialist. From Khmer Rouge supported by China , Khmer People's National Liberation Front and FUNCINPEC supported by United States and United Kingdom
  • 6.7K
  • 22 Nov 2022
Topic Review
Supercritical Water Gasification (SCWG)
Gasification with supercritical water (SCWG) is a thermochemical process which, exploiting the properties of supercritical water (374.1 °C and 22.1 MPa ), allows to obtain a syngas rich in hydrogen. Both biomass and waste plastic can be used as feedstock.
  • 6.6K
  • 18 Sep 2020
Topic Review
Eurostar
Eurostar is an international high-speed rail service connecting the United Kingdom with France , Belgium and the Netherlands. Most Eurostar trains travel through the Channel Tunnel between the United Kingdom and France, owned and operated separately by Getlink. The London terminus is London St Pancras International; the other British calling points are Ebbsfleet International and Ashford International in Kent. Intermediate calling points in France are Calais-Fréthun and Lille-Europe. Trains to Paris terminate at Gare du Nord. Trains to Belgium and the Netherlands serve Brussels-South and Rotterdam Centraal, before terminating at Amsterdam Centraal. Additionally, in France there are direct services from London to Marne-la-Vallée–Chessy (Disneyland Paris) and seasonal direct services to southern France (Lyon, Avignon and Marseille) in summer, and to the French Alps in winter. The service is operated by 11 Class 373/1 trainsets, each with 18 coaches, and 17 Class 374 trainsets, each with 16 coaches. The trains run at up to 320 kilometers per hour (200 mph) on high-speed lines. The LGV Nord high-speed line in France opened before Eurostar services began in 1994, and newer lines enabling faster journeys were added later: HSL 1 in Belgium and High Speed 1 in south-east England. The French and Belgian parts of the network are shared with Paris–Brussels Thalys services and TGV trains. Eurostar is operated by Eurostar International Limited (EIL), jointly owned by SNCF, the national railway of France (55%), investment firms (40%), and the National Railway Company of Belgium (5%).
  • 6.5K
  • 20 Nov 2022
Topic Review
76 Mm Gun M1
The 76 mm gun M1 was an American World War II–era tank gun developed by the U.S Ordnance Department in 1942 to supplement the 75 mm gun on the basic Medium tank M4. It was also used to arm the 76 mm Gun Motor Carriage M18 tank destroyer. Although the gun was tested in early August 1942 and classified on August 17, 1942, it was not until August 1943 that the Ordnance Department developed a mounting for the M4 tank that the tank forces would accept. It was not accepted for combat until July 1944. In January 1943, the decision was made to mount the 76 mm on the vehicle that would become the M18. By May 1944, it was being combat tested as the T70.
  • 6.5K
  • 11 Nov 2022
Topic Review
Royal Ordnance L7
The Royal Ordnance L7 is the basic model of the United Kingdom 's most successful tank gun. The L7 is a 105 mm L/52 rifled design by the Royal Ordnance Factories intended for use in armoured fighting vehicles, replacing the earlier 20-pounder (84 mm) tank gun mounted on the Centurion tank. The successful L7 gun has been fitted on many armored vehicles including the British Centurion (starting from the Mk. 5/2 variant), the German Leopard 1 and early variants of the US M1 Abrams (M1 and M1IP). The L7 is a popular weapon and continued in use even after it was superseded by the L11 series 120 mm rifled tank gun, for some Centurion tanks operating as Artillery Forward Observation and Armoured Vehicle, Royal Engineers (AVRE) vehicles. The L7, and adaptations of it, can be found as standard or retrofitted equipment on a wide variety of tanks developed during the Cold War.
  • 6.4K
  • 08 Nov 2022
Biography
William Boeing
William Edward Boeing (/ˈboʊɪŋ/; October 1, 1881 – September 28, 1956) was an United States aviation pioneer who founded The Boeing Company in 1916. Boeing was born in Detroit, Michigan to Marie M. Ortmann, from Vienna, Austria, and Wilhelm Böing (1846–1890) from Hagen-Hohenlimburg, Germany.[1] From a successful family, Wilhelm Böing emigrated to the United States in 1868 and initia
  • 6.4K
  • 05 Dec 2022
Topic Review
Czochralski Process
The Czochralski process is a method of crystal growth used to obtain single crystals of semiconductors (e.g. silicon, germanium and gallium arsenide), metals (e.g. palladium, platinum, silver, gold), salts and synthetic gemstones. The process is named after Polish scientist Jan Czochralski, who invented the method in 1915 while investigating the crystallization rates of metals. He made this discovery by accident: instead of dipping his pen into his inkwell, he dipped it in molten tin, and drew a tin filament, which later proved to be a single crystal. The most important application may be the growth of large cylindrical ingots, or boules, of single crystal silicon used in the electronics industry to make semiconductor devices like integrated circuits. Other semiconductors, such as gallium arsenide, can also be grown by this method, although lower defect densities in this case can be obtained using variants of the Bridgman-Stockbarger technique.
  • 6.4K
  • 24 Nov 2022
Topic Review
9K111 Fagot
The 9K111 Fagot (Russian: Фагот; "bassoon") is a second-generation tube-launched SACLOS wire-guided anti-tank missile system of the Soviet Union for use from ground or vehicle mounts. The 9K111 Fagot missile system was developed by the Tula KBP Design Bureau for Instrument Building. "9M111" is the GRAU designation of the missile. Its NATO reporting name is AT-4 Spigot.
  • 6.3K
  • 21 Oct 2022
Topic Review
Militarization of Police
The militarization of police is the use of military equipment and tactics by law enforcement officers. This includes the use of armored personnel carriers (APCs), assault rifles, submachine guns, flashbang grenades, grenade launchers, sniper rifles, and SWAT (special weapons and tactics) teams. The militarization of law enforcement is also associated with intelligence agency–style information gathering aimed at the public and political activists and with a more aggressive style of law enforcement. Criminal justice professor Peter Kraska has defined militarization of police as "the process whereby civilian police increasingly draw from, and pattern themselves around, the tenets of militarism and the military model". Observers have noted the militarizing of the policing of protests. Since the 1970s, riot police have fired at protesters using guns with rubber bullets or plastic bullets. Tear gas, which was developed by the United States Army for riot control in 1919, is still widely used against protesters. The use of tear gas in warfare is prohibited by various international treaties that most states have signed; however, its law enforcement or military use for domestic or non-combat situations is permitted. Concerns about the militarization of police have been raised by both ends of the political spectrum in the United States , with both the libertarian Cato Institute and the American Civil Liberties Union (ACLU) voicing criticisms of the practice. The Fraternal Order of Police has spoken out in favor of equipping law enforcement officers with military equipment, claiming that it increases the officers' safety and enables them to protect members of the public and other first responders (e.g., firefighters and emergency medical services personnel). However, a 2017 study showed that police forces which received military equipment were more likely to have violent encounters with the public, regardless of local crime rates. A 2018 study found that militarized police units in the United States were more frequently deployed to communities with large shares of African-Americans, even after controlling for local crime rates. Many countries also have a gendarmerie, which is a military force with law enforcement duties among the civilian population. France classifies some weapons as "intermediary force weapons" such as its LBD 40 refitted version of the Swiss B&T GL06 military grenade launcher, which is used in riot police situations or against individual persons in more specific interventions. While not having the full power of military guns, some weapons are heavier than regular police weaponry and are still lethal. These are often referred to with the "limited lethality" appellation.
  • 6.3K
  • 11 Oct 2022
Topic Review
Blended Learning
Blended learning is an approach to education that combines online educational materials and opportunities for interaction online with traditional place-based classroom methods. It requires the physical presence of both teacher and student, with some elements of student control over time, place, path, or pace. While students still attend "brick-and-mortar" schools with a teacher present, face-to-face classroom practices are combined with computer-mediated activities regarding content and delivery. Blended learning is also used in professional development and training settings. Since blended learning is highly context-dependent, a universal conception of it is difficult. Some reports have claimed that a lack of consensus on a hard definition of blended learning has led to difficulties in research on its effectiveness. A well-cited 2013 study broadly defined blended learning as a mixture of online and in-person delivery where the online portion effectively replaces some of the face-to-face contact time rather than supplementing it. Additionally, a 2015 meta-analysis that historically looked back at a comprehensive review of evidence-based research studies around blended learning, found commonalities in defining that blended learning was "considered a combination of traditional f2f [face to face] modes of instruction with online modes of learning, drawing on technology-mediated instruction, where all participants in the learning process are separated by distance some of the time." This report also found that all of these evidence-based studies concluded that student achievement was higher in blended learning experiences when compared to either fully online or fully face-to-face learning experiences. "Blended learning" is sometimes used in the same breath as "personalized learning" and differentiated instruction.
  • 6.2K
  • 17 Oct 2022
Topic Review
Pole Weapon
A pole weapon or pole arm is a close combat weapon in which the main fighting part of the weapon is fitted to the end of a long shaft, typically of wood, thereby extending the user's effective range and striking power. Pole weapons are predominantly melee weapons, with a subclass of spear-like designs fit for both thrusting and throwing. Because many pole weapons were adapted from agricultural implements or other fairly abundant tools, and contained relatively little metal, they were cheap to make and readily available. When warfare would break out and the belligerents had a poorer class who could not pay for dedicated military weapons, leaders would often appropriate tools as cheap weapons. The cost of training was comparatively minimal, since these conscripted farmers had spent most of their lives using these "weapons" in the fields. This made polearms the favored weapon of peasant levies and peasant rebellions the world over. Pole arms can be divided into three broad categories: those designed for extended reach and thrusting tactics used in pike square or phalanx combat; those designed to increase leverage (thanks to hands moving freely on a pole) to maximize centrifugal force against cavalry; and those designed for throwing tactics used in skirmish line combat. Because their versatility, high effectiveness and cheap cost, polearms experimentation led to many variants and were the most frequently used weapons on the battlefield: bills, picks, dane axes, spears, glaives, guandaos, pudaos, poleaxes, halberds, harpoons, sovnyas, tridents, naginatas, bardiches, war scythes, and lances are all varieties of pole arms. Pole arms were common weapons on post-classical battlefields of Asia and Europe. Their range and impact force made them effective weapons against armored warriors on horseback, because they could be dismounted and/or penetrate said armor. The Renaissance saw a plethora of varieties. Pole arms in modern times are largely constrained to ceremonial military units such as the Papal Swiss Guard or Yeomen of the Guard, or traditional martial arts. Chinese martial arts in particular have preserved a wide variety of weapons and techniques.
  • 6.2K
  • 09 Nov 2022
Topic Review
BeiDou Navigation Satellite System
The BeiDou Navigation Satellite System (BDS) is a Chinese satellite navigation system. It consists of two separate satellite constellations. The first BeiDou system, officially called the BeiDou Satellite Navigation Experimental System and also known as BeiDou-1, consists of three satellites which since 2000 has offered limited coverage and navigation services, mainly for users in China and neighboring regions. Beidou-1 was decommissioned at the end of 2012. The second generation of the system, officially called the BeiDou Navigation Satellite System (BDS) and also known as COMPASS or BeiDou-2, became operational in China in December 2011 with a partial constellation of 10 satellites in orbit. Since December 2012, it has been offering services to customers in the Asia-Pacific region. In 2015, China started the build-up of the third generation BeiDou system (BeiDou-3) in the global coverage constellation. The first BDS-3 satellite was launched on 30 March 2015. As of January 2018, nine BeiDou-3 satellites have been launched. BeiDou-3 will eventually consist of 35 satellites and is expected to provide global services upon completion in 2020. When fully completed, BeiDou will provide an alternative global navigation satellite system to the United States owned Global Positioning System (GPS), and is expected to be more accurate than the GPS. It was claimed in 2016 that BeiDou-3 will reach millimeter-level accuracy (with post-processing), which is ten times more accurate than the finest level of GPS. According to China Daily, in 2015, fifteen years after the satellite system was launched, it was generating a turnover of $31.5 billion per annum for major companies such as China Aerospace Science and Industry Corp, AutoNavi Holdings Ltd, and China North Industries Group Corp.
  • 6.2K
  • 29 Nov 2022
Topic Review
Fuel Dispenser
A fuel dispenser is a machine at a filling station that is used to pump gasoline, petrol, diesel, CNG, CGH2, HCNG, LPG, LH2, ethanol fuel, biofuels like biodiesel, kerosene, or other types of fuel into vehicles. Fuel dispensers are also known as bowsers (in Australia ), petrol pumps (in Commonwealth countries), or gas pumps (in North America).
  • 6.1K
  • 19 May 2025
Topic Review
Thorium-Based Nuclear Power
Thorium-based nuclear power generation is fueled primarily by the nuclear fission of the isotope uranium-233 produced from the fertile element thorium. A thorium fuel cycle can offer several potential advantages over a uranium fuel cycle [Note 1] —including much greater abundance of thorium found on Earth, superior physical and nuclear fuel properties, and reduced nuclear waste production. One advantage of thorium fuel is its low weaponization potential; it is difficult to weaponize the uranium-233/232 and plutonium-238 isotopes largely consumed in thorium reactors. Between 1999 and , the number of operational thorium reactors in the world has risen from zero, to a handful of research reactors, to commercial plans for producing full-scale thorium-based reactors for use as power plants on a national scale. Some believe thorium is key to developing a new generation of cleaner, safer nuclear power. In 2011 a group of scientists at the Georgia Institute of Technology assessed thorium-based power as "a 1000+ year solution or a quality low-carbon bridge to truly sustainable energy sources solving a huge portion of mankind’s negative environmental impact." However, development of thorium power has significant start-up costs. Development of breeder reactors in general (including thorium reactors, which are breeders by nature) will increase proliferation concerns. After studying the feasibility of using thorium, nuclear scientists Ralph W. Moir and Edward Teller suggested that thorium nuclear research should be restarted after a three-decade shutdown and that a small prototype plant should be built.
  • 6.0K
  • 18 Oct 2022
Topic Review
D-10 Tank Gun
The D-10 is a Soviet 100 mm tank gun developed in late World War II. It originally equipped the SU-100 tank destroyers and was later selected for the T-55 tank, equipping these as late as 1979. On the T-55 the D-10 continues to be in active service in many countries.
  • 5.9K
  • 19 Oct 2022
  • Page
  • of
  • 50
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of COVID-19
Encyclopedia of Engineering
Encyclopedia of Social Sciences
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Academic Video Service
Feedback