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Topic Review
N1 (Rocket)
The N1/L3 (from Ракета-носитель Raketa-nositel', "Carrier Rocket"; Cyrillic: Н1) was a super heavy-lift launch vehicle intended to deliver payloads beyond low Earth orbit. The N1 was the Soviet counterpart to the US Saturn V and was intended to enable crewed travel to the Moon and beyond, with studies beginning as early as 1959. Its first stage, Block A, remains the most powerful rocket stage ever flown. However, all four first stages flown failed mid-flight because a lack of static test firings meant that plumbing issues and other adverse characteristics with the large cluster of thirty engines and its complex fuel and oxidizer feeder system were not revealed earlier in development. The N1-L3 version was designed to compete with the United States Apollo program to land a person on the Moon, using a similar lunar orbit rendezvous method. The basic N1 launch vehicle had three stages, which were to carry the L3 lunar payload into low Earth orbit with two cosmonauts. The L3 contained one stage for trans-lunar injection; another stage used for mid-course corrections, lunar orbit insertion, and the first part of the descent to the lunar surface; a single-pilot LK Lander spacecraft; and a two-pilot Soyuz 7K-LOK lunar orbital spacecraft for return to Earth. The N1-L3 was underfunded and rushed, starting development in October 1965, almost four years after the Saturn V. The project was badly derailed by the death of its chief designer Sergei Korolev in 1966. Each of the four attempts to launch an N1 failed, with the second attempt resulting in the vehicle crashing back onto its launch pad shortly after liftoff. The N1 program was suspended in 1974, and officially canceled in 1976. All details of the Soviet crewed lunar programs were kept secret until the USSR was nearing collapse in 1989.
  • 6.1K
  • 30 Nov 2022
Topic Review
Michael Addition of Carbonyl Compounds to α,β-Unsaturated Nitroalkenes
The proline-catalyzed asymmetric Michael addition reaction of acetaldehyde with α,β-unsaturated nitroalkenes as synthetically useful routes to β-substituted derivatives of γ-Aminobutyric acid (GABA).
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  • 01 Jul 2022
Topic Review
ATtiny Microcontroller Comparison Chart
ATtiny (also known as TinyAVR) are a subfamily of the popular 8-bit AVR microcontrollers, which typically has fewer features, fewer I/O pins, and less memory than other AVR series chips. The first members of this family were released in 1999 by Atmel (later acquired by Microchip Technology in 2016).
  • 6.1K
  • 03 Nov 2022
Topic Review
Republicanism
Republicanism is a political ideology centred on citizenship in a state organized as a republic under which the people hold popular sovereignty. Many countries are "republics" in the sense that they are not monarchies. The word "republic" derives from the Latin noun-phrase res publica, which referred to the system of government that emerged in the 6th century BC following the expulsion of the kings from Rome by Lucius Junius Brutus and Collatinus. This form of government in the Roman state collapsed in the latter part of the 1st century BCE, giving way to what was a monarchy in form, if not in name. Republics re-occurred subsequently, with, for example, Renaissance Florence or early modern Britain. The concept of a republic became a powerful force in Britain's North American colonies, where it contributed to the American Revolution. In Europe, it gained enormous influence through the French Revolution and through the First French Republic of 1792–1804.
  • 6.1K
  • 12 Oct 2022
Topic Review
Plant Nutrition for Human Health
Is there any relationship between plant nutrition and human health? The overall response to this question is very positive, and a strong relationship between the nutrition of plants and humans has been reported. The nutritional status of edible plants consumed by humans can have a negative or positive impact on human health.
  • 6.1K
  • 14 Jul 2022
Topic Review
Autonomous Spaceport Drone Ship
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform. Construction of such ships was commissioned by aerospace company SpaceX to allow for recovery of rocket first-stages at sea for high-velocity missions which do not carry enough fuel to return to the launch site after lofting spacecraft onto an orbital trajectory. SpaceX has two operational drone ships and has a third under construction as of early 2018. Just Read the Instructions operates in the Pacific for launches from Vandenberg Air Force Base ; Of Course I Still Love You operates in the Atlantic for launches from Cape Canaveral. A Shortfall of Gravitas is under construction. (As of August 2018), 23 Falcon 9 flights have attempted to land on a drone ship, with 17 of them succeeding. The ASDS ships are a key component of the SpaceX reusable launch system development program which aims to significantly lower the price of space launch services through "full and rapid reusability." Any flights going to geostationary orbit or exceeding escape velocity will require landing at sea, encompassing about half of SpaceX missions.
  • 6.1K
  • 27 Oct 2022
Topic Review
Biocoagulant/bioflocculant application for drinking water
The utilization of metal-based conventional coagulants/flocculants to remove suspended solids from drinking water and wastewater is currently leading to new concerns. Alarming issues related to the prolonged effects on human health and further pollution to aquatic environments from the generated nonbiodegradable sludge are becoming trending topics. The utilization of biocoagulants/bioflocculants does not produce chemical residue in the effluent and creates nonharmful, biodegradable sludge.
  • 6.1K
  • 25 Dec 2020
Topic Review
Environmental Protection and Sustainable Development in Madagascar
Located on the East coast of Africa, Madagascar is the world’s fourth-biggest island; Madagascar is host to 12,000 species of vascular plants (96% endemic). Over 90% of all its wildlife is found nowhere else on earth, and 5% of all of the earth’s biodiversity is found in Madagascar. A place where environmental degradation problems have created severe erosion and water quality problems. Despite its biological and cultural diversity, Madagascar is among the poorest countries in the world, with approximately 78% of the population living in extreme poverty with an average income of less than USD 2 per day, and more than three-quarters of the population in rural areas engaged in natural resources dependent livelihood activities. 
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  • 07 Dec 2022
Topic Review
Different Types of Literature Review
Literature reviews are crucial for demonstrating progress and a comprehensive understanding of a subject. However, an unorganized growth in literature can lead to complicated and competing arguments, hindering progress. This research delves into different types of literature reviews and the common mistakes researchers make when conducting them. Learning how to efficiently conduct a literature review is essential for success in academia and professional careers.
  • 6.1K
  • 09 May 2023
Topic Review
Ivermectin during the COVID-19 Pandemic
Ivermectin (IVM) is a broad-spectrum antiparasitic agent, developed and funded by Merck & Co. in 1974 to control and eradicate onchocerciasis caused by the parasitic worm Onchocerca volvulus in West Africa, which in the 1980s infected approximately 340,000 people. At the time, Africa did not have the resources necessary to seek treatments for this condition. The avermectins, of which IVM is a member, were discovered by Professor Satoshi Ōmura as fermentation products of the bacterium Streptomyces avermitilis at the Kitasato Institute in Tokyo. For this discovery, he received the 2015 Nobel Prize in Physiology and Medicine, which he shared with William Campbell. IVM is used to treat onchocerciasis, lymphatic filariasis, strongyloidiasis and scabies, and, very recently, has been used to combat lice. The drug’s low cost, high efficacy, safety, and marked tropism for helminths, as well as the fact that it has almost no impact on human biochemistry, have led to the inclusion of IVM in the twentieth list of essential medicines and sixth list of vital medicines in children, a recommendation made by the expert committee of the World Health Organization (WHO) in 2019. The safety profile is attributed to its selective affinity for ion channels.
  • 6.1K
  • 22 Sep 2022
Topic Review
Poly(N-isopropylacrylamide)-Based Hydrogels
Poly(N-isopropylacrylamide) (PNIPAM) is a widely utilized negative thermosensitive polymer (as it has increased solubility with lowering of temperature, causing volume phase transition by forming hydrogen bonds) that has currently sparkled a lot of scientific inquisitiveness. Smart hydrogels based on PNIPAM demonstrate distinct thermoresponsive features close to a lower critical solution temperature (LCST) that enhance their capability in various biomedical applications such as drug delivery, tissue engineering, and wound dressings.
  • 6.1K
  • 29 Jul 2022
Topic Review
Communalism
Communalism usually refers to a system that integrates communal ownership and federations of highly localized independent communities. A prominent libertarian socialist, Murray Bookchin, defines the Communalism political philosophy that he developed as "a theory of government or a system of government in which independent communes participate in a federation", as well as "the principles and practice of communal ownership". The term 'government' in this case does not imply an acceptance of a State or top-down hierarchy. This usage of communalism appears to have emerged during the late 20th century to distinguish commune-based systems from other political movements and/or governments espousing (if not actually practicing) similar ideas. In particular, earlier communities and movements advocating such practices were often described as "anarchist", "socialist" and/or "communist". Many historical communities practicing utopian socialism or anarcho-communism did implement internal rules of communalist property ownership in the context of federated communalism. It is at least theoretically possible for a federation of communes to include communes which do not practice communalist rules of property, which is to say, that the overall national government may be a federation of communes, but that private property rather than communalist property is the order within each such commune. Karl Marx, often viewed as the founder of modern communism, criticized older forms, including primitive communism and/or utopian socialism, as poorly conceived and/or prone to disintegration in practice. Communalism in the form described above is distinct from the predominant usage in South Asian forms of English: allegiance to a particular ethnic and/or religious group rather than to a broader society. As such, this usage is synonymous with sectarianism and associated with communal violence.
  • 6.1K
  • 16 Nov 2022
Topic Review
Supercontinent Cycle
The supercontinent cycle is the quasi-periodic aggregation and dispersal of Earth's continental crust. There are varying opinions as to whether the amount of continental crust is increasing, decreasing, or staying about the same, but it is agreed that the Earth's crust is constantly being reconfigured. One complete supercontinent cycle is said to take 300 to 500 million years. Continental collision makes fewer and larger continents while rifting makes more and smaller continents.
  • 6.1K
  • 03 Nov 2022
Topic Review
Organ
In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a function. Tissues of different types combine to form an organ which has a specific function. The intestinal wall for example is formed by epithelial tissue and smooth muscle tissue. Two or more organs working together in the execution of a specific body function form an organ system, also called a biological system or body system. An organ's tissues can be broadly categorized as parenchyma, the functional tissue, and stroma, the structural tissue with supportive, connective, or ancillary functions. For example, the gland's tissue that makes the hormones is the parenchyma, whereas the stroma includes the nerves that innervate the parenchyma, the blood vessels that oxygenate and nourish it and carry away its metabolic wastes, and the connective tissues that provide a suitable place for it to be situated and anchored. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Organs exist in most multicellular organisms. In single-celled organisms such as bacteria, the functional analogue of an organ is known as an organelle. In plants, there are three main organs. In the study of anatomy, viscera (singular viscus) refers to the internal organs of the abdominal, thoracic, and pelvic cavities. The abdominal organs may be classified as solid organs, or hollow organs. The solid organs are the liver, pancreas, spleen, kidneys, and adrenal glands. The hollow organs of the abdomen are the stomach, intestines, gallbladder, bladder, and rectum. In the thoracic cavity the heart is a hollow, muscular organ. The number of organs in any organism depends on the definition used. By one widely adopted definition, 79 organs have been identified in the human body.
  • 6.1K
  • 14 Oct 2022
Topic Review
2015–16 Chinese Stock Market Turbulence
The Chinese stock market turbulence began with the popping of the stock market bubble on 12 June 2015 and ended in early February 2016. A third of the value of A-shares on the Shanghai Stock Exchange was lost within one month of the event. Major aftershocks occurred around 27 July and 24 August's "Black Monday". By 8–9 July 2015, the Shanghai stock market had fallen 30 percent over three weeks as 1,400 companies, or more than half listed, filed for a trading halt in an attempt to prevent further losses. Values of Chinese stock markets continued to drop despite efforts by the government to reduce the fall. After three stable weeks the Shanghai index fell again on 24 August by 8.48 percent, marking the largest fall since 2007. At the October 2015 International Monetary Fund (IMF) annual meeting of "finance ministers and central bankers from the Washington-based lender’s 188 member-countries" held in Peru, China's slump dominated discussions with participants asking if "China’s economic downturn [would] trigger a new financial crisis". By the end of December 2015 China's stock market had recovered from the shocks and had outperformed S&P for 2015, though still well below the 12 June highs. By the end of 2015 the Shanghai Composite Index was up 12.6 percent. In January 2016 the Chinese stock market experienced a steep sell-off and trading was halted on 4 and 7 January 2016 after the market fell 7%, the latter within 30 minutes of open. The market meltdown set off a global rout in early 2016. According to 19 January 2016 articles in the Xinhua News Agency, the official press agency of the China , China reported a 6.9 percent GDP growth rate for 2015 and an "economic volume of over ten trillion U.S. dollars". Forbes journalist argues that the "stock market crash does not indicate a blowout of the Chinese physical economy." China is shifting from a focus on manufacturing to service industries and while it has slowed down, it is still growing by 5%. After this last turbulence, as of January 2017 the Shanghai Composite Index has been stable around 3,000 points, 50% less than before the bubble popped.
  • 6.1K
  • 28 Nov 2022
Topic Review
Trickster
In mythology, and in the study of folklore and religion, a trickster is a character in a story (god, goddess, spirit, human, or anthropomorphisation), which exhibits a great degree of intellect or secret knowledge, and uses it to play tricks or otherwise disobey normal rules and conventional behaviour.
  • 6.1K
  • 03 Nov 2022
Topic Review
List of Aircraft (P)
This is a list of aircraft in alphabetical order beginning with 'P'.
  • 6.1K
  • 19 Oct 2022
Topic Review
Diarchy
A diarchy (from Greek δι-, di-, "double", and -αρχία, -arkhía, "ruled")[note 1] or duumvirate (from Latin duumvirātus, "the office of the two men")[note 2] is a form of government characterized by corule, with two people ruling a polity together either lawfully or de facto, by collusion and force. The leaders of such a system are usually known as corulers. Historically, diarchy particularly referred to the system of shared rule in British India established by the Government of India Acts 1919 and 1935, which devolved some powers to local councils, which had included native Indian representation under the Indian Councils Act 1892. 'Duumvirate' principally referred to the offices of the various duumviri established by the Roman Republic. Both, along with less common synonyms such as biarchy and tandemocracy,[note 3] are now used more generally to refer to any system of joint rule or office. A monarchy temporarily controlled by two or more people is, however, usually distinguished as a coregency. Corule is one of the oldest forms of government. Historical examples include the Pandyan dynasty of Tamilakam, Sparta's joint kingdom, the Roman Republic's consuls, Carthage's Judges, and several ancient Polynesian societies. Systems of inheritance that often led to corule in Germanic and Dacian monarchies may be included as well, as may the dual occupants of the ranks of the Inca Empire. Modern examples of diarchies are Andorra, whose princes are the President of France and the Bishop of Urgell in Catalonia; and San Marino, whose republic is led by two Captains Regent.
  • 6.1K
  • 14 Nov 2022
Topic Review
Railway Nationalization
Railway nationalization is the act of taking rail transport assets into public ownership. Several countries have at different times nationalized part or all of their railway system. More recently, the international trend has been towards privatization. In some areas, notably Great Britain, resultant problems with track maintenance have led back to a more mixed solution, with a nationalised infrastructure operator but privately run train operating companies. National characteristics influenced the structures under which countries' rail networks developed. Some national railways were always under direct State management, some were State-planned but privately operated (as in France, others were wholly private enterprises lightly regulated (as in Great Britain, Ireland and Spain). Nationalization was therefore a bolder step to take in some countries than in others. While ideology has played a role, so too has the need for systematic reconstruction of vital infrastructure devastated by war, often following a period of State control over private companies initiated during the conflict.
  • 6.1K
  • 01 Dec 2022
Topic Review
Location-Based Social Networks
There are several definitions for “geosocial network” or “location-based social network”: the first formal definition was given by Quercia et al. in 2010, who defined it as “a type of social networking in which geographic services and capabilities such as geocoding and geotagging are used to enable additional social dynamics”. One year later, Zheng refined this definition by stating that “a location-based social network (LBSN) does not only mean adding a location to an existing social network so that people in the social structure can share location embedded information but also consists of the new social structure made up of individuals connected by the interdependency derived from their locations in the physical world as well as their location-tagged media content, such as photos, video, and texts”. In 2013, Roick and Heuser defined LBSNs simply as “social network sites that include location information into shared contents”. Finally, one most recent definition is given by Armenatzoglou and Papadias and is the following: “geosocial network (GeoSN) is an online social network augmented by geographical information”.
  • 6.0K
  • 17 Jan 2022
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