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Topic Review
Nag (Missile)
The Nag missile (IAST: Nāga; en: Cobra), also called "Prospina" for the land-attack version, is an India n third-generation, all-weather, fire-and-forget, lock-on after launch, anti-tank guided missile (ATGM) with an operational range of 500 m to 20 km. It has a single-shot hit probability of 90% and a ten-year, maintenance-free shelf life. The Nag has five variants under development: a land version, for a mast-mounted system; the helicopter-launched Nag (HELINA) also known as Dhruvastra; a "man-portable" version (MPATGM); an air-launched version which will replace the current imaging infra-red (IIR) to millimetric-wave (mmW) active radar homing seeker; and the Nag Missile Carrier (NAMICA) "tank buster", which is a modified BMP-2 Infantry Fighting Vehicle (IFV) produced under license in India by Ordnance Factory Medak (OFMK). Development of the Nag is part of the Integrated Guided Missile Development Program (IGMDP), run by Defence Research and Development Organisation (DRDO). It is manufactured by Bharat Dynamics Limited (BDL). India's Ministry of Defence (MoD) announced on 19 July 2019 that the missile was ready for production. The Defence Research and Development Organization (DRDO) successfully completed the final trial of Nag anti-tank missile using a live warhead on a dud tank at Pokhran army ranges at 6.45 am on Oct 21, 2020.
  • 8.8K
  • 09 Oct 2022
Topic Review
Spark Gap
A spark gap consists of an arrangement of two conducting electrodes separated by a gap usually filled with a gas such as air, designed to allow an electric spark to pass between the conductors. When the potential difference between the conductors exceeds the breakdown voltage of the gas within the gap, a spark forms, ionizing the gas and drastically reducing its electrical resistance. An electric current then flows until the path of ionized gas is broken or the current reduces below a minimum value called the "holding current". This usually happens when the voltage drops, but in some cases occurs when the heated gas rises, stretching out and then breaking the filament of ionized gas. Usually, the action of ionizing the gas is violent and disruptive, often leading to sound (ranging from a snap for a spark plug to thunder for a lightning discharge), light and heat. Spark gaps were used historically in early electrical equipment, such as spark gap radio transmitters, electrostatic machines, and X-ray machines. Their most widespread use today is in spark plugs to ignite the fuel in internal combustion engines, but they are also used in lightning arresters and other devices to protect electrical equipment from high-voltage transients.
  • 8.8K
  • 08 Oct 2022
Topic Review
Acer Aspire Laptops
Acer Aspire (stylized as Λspire or ΛSPIRE) is a series of personal computers by Acer Inc. aimed at the casual household user or for small business use. The Aspire series covers both desktop computers and laptops. Acer developed the series in order to cover from essentials to high performances. Many of the Aspire laptops, such as model 8920G, have built in Blu-ray drives, 5.1 audio outputs and transflective displays. Acer was the first to include these drives in laptops. Most Aspire laptops have water-resistant screens, such as the 1410 and the 5741 Z. In 2007, Acer introduced the Gemstone series that marked a milestone in the Acer Aspire line. As with many Windows laptops, different models may have different specification in different parts of the world.
  • 8.8K
  • 20 Oct 2022
Topic Review
SpaceX Dragon 2
The SpaceX Dragon 2 is a class of reusable spacecraft developed and manufactured by American aerospace manufacturer SpaceX as the successor to the Dragon cargo spacecraft. It has two variants: Crew Dragon, a human-rated capsule capable of ferrying up to seven astronauts, and Cargo Dragon, an updated replacement for the original Dragon spacecraft. The spacecraft launches atop a Falcon 9 Block 5 rocket and returns to Earth via an ocean splashdown. Unlike its predecessor, the spacecraft can dock itself to the ISS instead of being berthed. Crew Dragon is equipped with an integrated launch escape system (LES) capable of accelerating the vehicle away from the rocket in an emergency at 11.8 m/s2, accomplished by using a set of four side-mounted thruster pods with two SuperDraco engines each. The spacecraft features redesigned solar arrays and a modified outer mold line compared to the original Dragon, and possess new flight computers and avionics. As of March 2020, four Dragon 2 spacecraft have been manufactured (not counting structural test articles that were never airborne). Crew Dragon serves as one of two spacecraft that is expected to transport crews to and from the International Space Station (ISS) under NASA's Commercial Crew Program, the other being the Boeing CST-100 Starliner. It is also expected to be used in flights by American space tourism company Space Adventures and to shuttle tourists to and from Axiom Space's planned space station. Crew Dragon's first non-piloted test flight occurred in March 2019, and its first crewed flight – with astronauts Robert Behnken and Douglas Hurley – occurred in May 2020. This test flight marked the first time a private company launched a crewed orbital spacecraft. Cargo Dragon is expected to supply cargo to the ISS under a Commercial Resupply Services-2 contract with NASA, along with Northrop Grumman Innovation Systems' Cygnus spacecraft and Sierra Nevada Corporation's Dream Chaser spacecraft. The first flight of the Cargo Dragon is planned to launch in October 2020.
  • 8.1K
  • 26 Oct 2022
Topic Review
Green Monopropellants
Green propellants are usually defined as low-hazard, low-toxicity, environmentally friendly propellants that are considered safe during various phases of spacecraft development, launch, and operations. Such propellants provide safe handling and storability when compared to conventional toxic propellants such as hydrazine and its derivatives that require special handling protocols and adhering to strict safety measurements that, in addition to others, include using Self-Contained Atmospheric Protective Ensemble (SCAPE) suits. Due to their favorable characteristics, green propellants demonstrate higher commercial value by being able to cut costs related to transportation, storage, handling, and further reduces ground operations time. Recently, a more specified definition has been noted by Mayer et al. (2018) [3], based on the Acute Toxicity Classification (ATC) by the Global Harmonized System of classification and labeling of chemicals (GHS) [6], which denotes that propellants possessing ATC levels of three and safer are considered as green propellants. ATC levels are typically categorized on a 1:5 scale where level one denotes the most toxic class and level five is considered the least toxic class. Moreover, a controversial topic arises when referring to some modern green propellants, whether to address them by the term “monopropellants” or by more specific terms including (premixed propellants, fuel blends, or mixtures). Monopropellants are fundamentally defined as propellants consisting of chemical compounds (for example N2H4), which release energy through exothermic chemical decomposition. Since the evolution of liquid gun propellants based on HAN compound and other nitrate salts aqueous solutions, the term “monopropellants” was used to describe such premixed formulations. As widely used in literature and industry, some modern green propellants, for instance the Energetic Ionic Liquids (EILs), are undoubtedly classified and described as “monopropellants.” Basically, it can be interpreted from the previous that a "green monopropellant" may be defined as: "A low-hazard, low-toxicity, and safe-to handle propellant that is stored in a single tank and is able to decompose from its storage state by the help of a catalyst or other ignition method, such as thermal or electric ignition, can be considered a “green monopropellant” as long as it does not require another separately stored propellant for decomposition."
  • 8.1K
  • 28 Sep 2021
Biography
Shahid Khan
Shahid Khan (Urdu: شاہد خان‎; born July 18, 1950),[1][2] also known as Shad Khan, is a Pakistani-American billionaire businessman and philanthropist. He is the owner of the Jacksonville Jaguars of the National Football League (NFL) and Fulham F.C. of the English Premier League. Khan is also the owner of the automobile parts manufacturer Flex-N-Gate in Urbana, Illinois. Khan was feature
  • 8.0K
  • 30 Nov 2022
Topic Review
Ghauri (Missile)
The Ghauri–I (Urdu: غوری-ا‎; official codename: Hatf–5 Ghauri–I) is a land-based surface-to-surface medium-range ballistic missile, in current service with the Pakistan Army's Strategic Forces Command— a subordinate command of Strategic Plans Division. Influenced from the design of Nodong-1 of North Korea, its extensive modification and engineering took place in Kahuta Research Laboratories (KRL) in 1990s with an objective of developing an electronic system that uses a single stage liquid fuel rocket motor to carry a payload of 700 kg to a range of 1,500 km. This is enough to reach most, if not all of India. Two variants of the Ghauri were produced under the secretive missile research programme started in 1987 and the development of a third variant was cancelled. The Ghauri-II uses increased motor assembly length and improved propellants for an increased range of 2,300 km (1,400 mi). The missile is named after Shahabuddin Muhammad Ghauri, while the "Hatf" designation originates from the name of the sword or lance of the Islamic prophet Muhammad.
  • 8.0K
  • 09 Nov 2022
Topic Review
AMD Radeon Rx 200 Series
The AMD Radeon R5/R7/R9 200 series is a family of GPUs developed by AMD. These GPUs are manufactured on a 28 nm Gate-Last process through TSMC or Common Platform Alliance.
  • 8.0K
  • 18 Oct 2022
Topic Review
Ghazal
The ghazal (Bengali: গজল, Sylheti: ꠊꠏꠟ, Punjabi: ਗ਼ਜ਼ਲ, Urdu: غزَل , Hindi: ग़ज़ल, Persian: غزل‎, Azerbaijani: qəzəl, Turkish: gazel, Uzbek: gʻazal, Pashto: غزل‎, Template:Lang-gu,) is a form of amatory poem or ode, originating in Arabic poetry. A ghazal may be understood as a poetic expression of both the pain of loss or separation and the beauty of love in spite of that pain. The ghazal form is ancient, tracing its origins to 7th-century Arabic poetry. The ghazal spread into South Asia in the 12th century due to the influence of Sufi mystics and the courts of the new Islamic Sultanate, and is now most prominently a form of poetry of many languages of the Indian subcontinent and Turkey. A ghazal commonly consists of between five and fifteen couplets, which are independent, but are linked – abstractly, in their theme; and more strictly in their poetic form. The structural requirements of the ghazal are similar in stringency to those of the Petrarchan sonnet. In style and content, due to its highly allusive nature, the ghazal has proved capable of an extraordinary variety of expression around its central themes of love and separation.
  • 7.9K
  • 24 Nov 2022
Topic Review
Intelligent Tutoring System
An intelligent tutoring system (ITS) is a computer system that aims to provide immediate and customized instruction or feedback to learners, usually without requiring intervention from a human teacher. ITSs have the common goal of enabling learning in a meaningful and effective manner by using a variety of computing technologies. There are many examples of ITSs being used in both formal education and professional settings in which they have demonstrated their capabilities and limitations. There is a close relationship between intelligent tutoring, cognitive learning theories and design; and there is ongoing research to improve the effectiveness of ITS. An ITS typically aims to replicate the demonstrated benefits of one-to-one, personalized tutoring, in contexts where students would otherwise have access to one-to-many instruction from a single teacher (e.g., classroom lectures), or no teacher at all (e.g., online homework). ITSs are often designed with the goal of providing access to high quality education to each and every student.
  • 7.9K
  • 10 Oct 2022
Topic Review
Semaphore Telegraph
A semaphore telegraph is an early system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the mechanical elements; it is read when the shutter is in a fixed position. The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries. Lines of relay towers with a semaphore rig at the top were built within line-of-sight of each other, at separations of 5–20 miles (8.0–32.2 km). Operators at each tower would watch the neighboring tower through a spyglass, and when the semaphore arms began to move spelling out a message, they would pass the message on to the next tower. This system was much faster than post riders for conveying a message over long distances, and also had cheaper long-term operating costs, once constructed. Semaphore lines were a precursor of the electrical telegraph, which would replace them half a century later, and would also be cheaper, faster, and more private. The line-of-sight distance between relay stations was limited by geography and weather, and prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. Modern derivatives of the semaphore system include flag semaphore (a flag relay system) and the heliograph (optical telegraphy using mirror-directed sunlight reflections).
  • 7.8K
  • 28 Nov 2022
Topic Review
Luxury Vehicle
A luxury vehicle provides increased levels of comfort, equipment, amenities, quality, performance, and status relative to regular cars for an increased price. The term is subjective and reflects both the qualities of the car and the brand image of its manufacturer. Luxury brands rank above premium brands, though there is no fixed demarcation between the two. Traditionally, most luxury cars were large vehicles, though smaller sports-oriented models were always produced. “Compact“ luxury vehicles such as hatchbacks, and off-road capable sport utility vehicles, are relatively modern trends.
  • 7.7K
  • 27 Oct 2022
Topic Review
BMW 5 Series Gran Turismo
The BMW 5 Series Gran Turismo (also referred to as "5 Series GT") models are the 5-door fastback versions of the F10 5 Series model range and use the model code F07. The F07 uses the F10 platform and shares many components with the other 5 Series models. It was released in 2009. Engine choices were turbocharged straight-6 petrol, straight-6 diesel and V8 petrol. At launch, all models were rear-wheel drive ("sDrive"), with all-wheel drive ("xDrive") models being added in 2010. For the following G30 generation, the Gran Turismo models were moved to the 6 Series model range and renamed the G32 6 Series Gran Turismo.
  • 7.7K
  • 29 Sep 2022
Topic Review
FN Baby Browning
The 1931 Fabrique Nationale ("FN") Baby Browning Pistol is a small blowback-operated semi-automatic pistol designed by Belgium-born Dieudonné Saive chambered in .25 ACP (6,35mm). The pistol features a six-round magazine capacity and is a striker-fired, single action, blow back mechanism. The manual thumb operated safety locks the slide in the closed position when engaged using side thumb pressure.
  • 7.7K
  • 14 Oct 2022
Topic Review
Pot-in-pot Refrigerator
A pot-in-pot refrigerator, clay pot cooler or zeer (Arabic: زير) is an evaporative cooling refrigeration device which does not use electricity. It uses a porous outer earthenware pot (lined with wet sand) containing an inner pot (which can be glazed to prevent penetration by the liquid) within which the food is placed. The evaporation of the outer liquid draws heat from the inner pot. The device can cool any substance, and requires only a flow of relatively dry air and a source of water.
  • 7.6K
  • 09 Oct 2022
Topic Review
Derringer
A derringer is a small handgun that is neither a revolver nor a semi/fully automatic pistol. It is not to be confused with mini-revolvers or pocket pistols, although some later derringers were manufactured with the pepperbox configuration. The modern derringer is often multi-barreled, and is generally the smallest usable handgun of any given caliber and barrel length due to the lack of a moving action, which takes up more space behind the barrel. It is frequently used by women because it is easily concealable in a purse or a stocking. The original Philadelphia Deringer was a muzzleloading caplock single-shot pistol introduced in 1825 by Henry Deringer. In total, approximately 15,000 Deringer pistols were manufactured. All were single barrel pistols with back-action percussion locks, typically .41 caliber with rifled bores, and walnut stocks. Barrel length varied from 1.5 to 6 in (38 to 152 mm), and the hardware was commonly a copper-nickel alloy known as "German silver". The term "derringer" (/ˈdɛrɪndʒər/) became a genericized misspelling during the reporting of the Lincoln assassination, which was committed with a concealed Philadelphia Deringer. Many copies of the original Philadelphia Deringer pistol were made by other gunmakers worldwide, and the name remained often misspelled; this misspelling soon became an alternative generic term for any pocket pistol, along with the generic phrase "palm pistol'", which Deringer's competitors invented and used in their advertising. With the advent of metallic cartridges, pistols produced in the modern form are still commonly called "derringers".
  • 7.6K
  • 01 Nov 2022
Topic Review
Nose Ring (Animal)
A nose ring is inserted into the nose of an animal. Nose rings are used to control bulls and occasionally cows, and to help wean young cattle by preventing suckling. Nose rings are used on pigs to discourage rooting. Some nose rings are installed through a pierced hole in the nasal septum or rim of the nose and remain there, while others are temporary tools.
  • 7.4K
  • 03 Nov 2022
Topic Review
Tin Can
A tin can, tin (especially in British English, Australian English and Canadian English), steel can, steel packaging or a can, is a container for the distribution or storage of goods, composed of thin metal. Many cans require opening by cutting the "end" open; others have removable covers. Cans hold diverse contents: foods, beverages, oil, chemicals, etc. Steel cans are made of tinplate (tin-coated steel) or of tin-free steel. In some dialects, even aluminium cans are called "tin cans".
  • 7.4K
  • 26 Oct 2022
Topic Review
E-learning (Theory)
E-learning theory describes the cognitive science principles of effective multimedia learning using electronic educational technology.
  • 7.3K
  • 25 Nov 2022
Topic Review
Zip (File Format)
ZIP files generally use the file extensions .zip or .ZIP and the MIME media type application/zip. ZIP is used as a base file format by many programs, usually under a different name. When navigating a file system via a user interface, graphical icons representing ZIP files often appear as a document or other object prominently featuring a zipper.
  • 7.3K
  • 14 Oct 2022
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