Summary

HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Federation (Spacecraft)
Federation (Russian: Федерация, Federatsiya), formerly called PPTS (Prospective Piloted Transport System, Перспективная Пилотируемая Транспортная Система, Perspektivnaya Pilotiruemaya Transportnaya Sistema) is a project by Roscosmos to develop a new-generation, partially reusable piloted spacecraft. Until 2016 its official name was Пилотируемый Транспортный Корабль Нового Поколения, Pilotiruemyi Transportny Korabl Novogo Pokoleniya or PTK NP meaning "New Generation Piloted Transport Ship". The goal of the project is to develop a new-generation spacecraft to replace the aging Soyuz spacecraft developed by the former Soviet Union to support low Earth orbit and lunar operations. It is similar in function to the United States Orion spacecraft. The PPTS project was started following the failed attempt by Russia and the European Space Agency to co-develop the Crew Space Transportation System (CSTS), which until the middle of 2006 was known as the ACTS. Following this the Russian Federal Space Agency ordered the local space industry to finalize proposals for the new manned spacecraft. A firm development contract was awarded to RKK Energia on December 19, 2013. Federation will be capable of carrying crews of four into Earth orbit and beyond on missions of up to 30 days. If docked with a space station, it could stay in space up to a year, which is double the duration of the Soyuz spacecraft. The spacecraft will send cosmonauts to the moon orbit, with a plan to place a space station there.
  • 1.1K
  • 01 Nov 2022
Topic Review
Chemical Explosive
The vast majority of explosives are chemical explosives. Explosives usually have less potential energy than fuels, but their high rate of energy release produces a great blast pressure. TNT has a detonation velocity of 6,940 m/s compared to 1,680 m/s for the detonation of a pentane-air mixture, and the 0.34-m/s stoichiometric flame speed of gasoline combustion in air. The properties of the explosive indicate the class into which it falls. In some cases explosives can be made to fall into either class by the conditions under which they are initiated. In sufficiently large quantities, almost all low explosives can undergo a Deflagration to Detonation Transition (DDT). For convenience, low and high explosives may be differentiated by the shipping and storage classes.
  • 1.7K
  • 01 Nov 2022
Topic Review
High-explosive Anti-tank Warhead
A high-explosive anti-tank (HEAT) warhead is a type of shaped charge explosive that uses the Munroe effect to penetrate thick tank armor. The warhead functions by having the explosive charge collapse a metal liner inside the warhead into a high-velocity superplastic jet. This superplastic jet is capable of penetrating armor steel to a depth of seven or more times the diameter of the charge (charge diameters, CD) but is usually used to immobilize or destroy tanks. Due to the way they work, they do not have to be fired as fast as an armor piercing shell, allowing less recoil. Contrary to a widespread misconception (possibly resulting from the acronym HEAT), the jet does not melt its way through armor, as its effect is purely kinetic in nature. The HEAT warhead has become less effective against tanks and other armored vehicles due to the use of composite armor, explosive-reactive armor, and active protection systems which destroy the HEAT warhead before it hits the tank. While HEAT ammunition has become less effective against the composite armor found on MBTs from 1964 onward and today pose little threat to any modern tank, they are still deadly against lighter vehicles. In addition, air vehicles are also possible targets.
  • 3.7K
  • 01 Nov 2022
Topic Review
Ochlocracy
Ochlocracy (Greek: ὀχλοκρατία, romanized: okhlokratía; Latin: ochlocratia) or mob rule is the rule of government by a mob or mass of people and the intimidation of legitimate authorities. Insofar as it represents a pejorative for majoritarianism, it is akin to the Latin phrase mobile vulgus, meaning "the fickle crowd", from which the English term "mob" originally was derived in the 1680s. Ochlocracy is synonymous in meaning and usage to the modern, informal term "mobocracy", which arose in the 18th century as a colloquial neologism. Likewise, whilst the ruling mobs in ochlocracies may sometimes genuinely reflect the will of the majority in a manner approximating democracy, ochlocracy is characterized by the absence or impairment of a procedurally civil and democratic process.
  • 4.1K
  • 01 Nov 2022
Topic Review
Peppercorn (Legal)
In legal parlance, a peppercorn is a metaphor for a very small cash payment or other nominal consideration, used to satisfy the requirements for the creation of a legal contract. It is featured in Chappell & Co Ltd v Nestle Co Ltd ( AC 87), which stated that "a peppercorn does not cease to be good consideration if it is established that the promisee does not like pepper and will throw away the corn". What is unusual about the term is that it came into the language when peppercorns were extremely expensive; coming, as they exclusively did, from the Dutch Moluccas. Yet today, the term is more-or-less synonymous with ”a pittance“ — something of minimal value.
  • 5.6K
  • 01 Nov 2022
Topic Review
Post-canine Megadontia
Post-canine megadontia is a relative enlargement of the molars and premolars compared to the size of the incisors and canines. This phenomenon is seen in some early hominid ancestors such as Paranthropus aethiopicus.
  • 2.1K
  • 01 Nov 2022
Topic Review
Simulation Argument (Programmer God)
The simulation hypothesis or simulation theory is the proposal that all of reality, including the Earth and the rest of the universe, could in fact be an artificial simulation, such as a computer simulation. Neil deGrasse Tyson put the odds at 50-50 that our entire existence is a program on someone else’s hard drive . David Chalmers noted “We in this universe can create simulated worlds and there’s nothing remotely spooky about that. Our creator isn’t especially spooky, it’s just some teenage hacker in the next universe up. Turn the tables, and we are essentially gods over our own computer creations . The commonly postulated ancestor simulation approach, which Nick Bostrom called "the simulation argument", argues for "high-fidelity" simulations of ancestral life that would be indistinguishable from reality to the simulated ancestor. However this simulation variant can be traced back to an 'organic base reality' (the original programmer ancestors). The Programmer God hypothesis conversely states that the simulation began with the big bang and was programmed by an external intelligence (external to the physical universe), the Programmer by definition a God in the creator of the universe context.
  • 1.9K
  • 03 Nov 2022
Topic Review
SYmbolic LinK (SYLK)
Symbolic Link (SYLK) is a Microsoft file format typically used to exchange data between applications, specifically spreadsheets. SYLK files conventionally have a .slk suffix. Composed of only displayable ANSI characters, it can be easily created and processed by other applications, such as databases. Microsoft does not publish a SYLK specification. Variants of the format are supported by Multiplan, Microsoft Excel, Microsoft Works, OpenOffice.org, and Gnumeric. The format was introduced in the 1980s and has not evolved since 1986. A commonly encountered (and spurious) 'occurrence' of the SYLK file happens when a comma-separated value (CSV) format is saved with an unquoted first field name of 'ID', that is the first two characters match the first two characters of the SYLK file format. Microsoft Excel (at least to Office 2016) will then emit misleading error messages relating to the format of the file, such as "The file you are trying to open, 'x.csv', is in a different format than specified by the file extension...". SYLK is known to cause security issues, as it allows an attacker to run arbitrary code, offers the opportunity to disguise the attack vector under the benign-looking appearance of a CSV file, and is still enabled by default on recent (2016) versions of Microsoft Excel.
  • 1.0K
  • 01 Nov 2022
Topic Review
Photonic Laser Thruster
A photonic laser thruster (PLT) is an amplified photonic propulsion thruster for space propulsion that works on the principle of a photon-pushed sail, generating thrust directly from the momentum of a photon from a laser reflected from a mirror. The thruster, invented by Young K. Bae differs from other solar sail and laser propulsion thrusters in that an amplification process is used, in which the incident beam is re-used by being reflected by a stationary mirror, with an amplification stage at each reflection. Because of the recycling of energy, the photonic laser thruster has been demonstrated to be more energy efficient than other laser-pushed sail concepts. The near-term usage of the photonic laser thruster the earth-orbit applications include propellant-free and thrust-plume-contamination-free spacecraft maneuvering for precision formation flying, large optical and RF synthetic aperture construction, and stationkeeping. The usage of the photonic laser thruster for main space propulsion would require scaling-up of the laser power and controlling laser diffraction over interplanetary and interstellar distances. Photonic laser thrusters have a very high specific impulse, and can permit spacecraft to reach much higher speeds that approach a fraction of the light speed, unlike conventional rockets, which are limited by the Tsiolkovsky rocket equation.
  • 4.7K
  • 01 Nov 2022
Topic Review
40M Turán
The Turán was a Hungarian medium tank of World War II. It was inspired and used the technology-based solutions found on the design of the Czechoslovak Škoda T-21 medium tank prototype, it was produced in two main variants: the 40M Turán (or Turán I) with a 40 mm gun and the 41M Turán (or Turán II) with a 75 mm gun. A total of 424 were made. A prototype variant, the 43M Turán (or Turán III) was also turned out but did not go into production. Prototypes were manufactured, but work on the project stopped in 1944 when the mass-producing terminated in the country.
  • 1.5K
  • 01 Nov 2022
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