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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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The Foundations of Arithmetic
The Foundations of Arithmetic (German: Die Grundlagen der Arithmetik) is a book by Gottlob Frege, published in 1884, which investigates the philosophical foundations of arithmetic. Frege refutes other theories of number and develops his own theory of numbers. The Grundlagen also helped to motivate Frege's later works in logicism. The book was not well received and was not read widely when it was published. It did, however, draw the attentions of Bertrand Russell and Ludwig Wittgenstein, who were both heavily influenced by Frege's philosophy. An English translation was published (Oxford, 1950) by J. L. Austin, with a second edition in 1960.
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  • 05 Dec 2022
Topic Review
BMW 5 Series (E39)
The BMW E39 is the fourth generation of BMW 5 Series, which was sold from 1995 to 2004. It was launched in the sedan body style, with the wagon/estate body style (marketed as "Touring") introduced in 1996. The E39 was replaced by the E60 5 Series in 2003, however E39 Touring models remained in production until May 2004. The proportion of chassis components using aluminium significantly increased for the E39, and it was the first 5 Series to use aluminium for all major components in the front suspension or any in the rear. It was also the first 5 Series where a four-cylinder diesel engine was available. Rack and pinion steering was used for the first time in a 5 Series (with the exception of the E34 525iX), being fitted to the four-cylinder and six-cylinder models. Unlike its E34 predecessor and E60 successor, the E39 was not available with all-wheel drive. The high performance M5 sedan was introduced in 1998, powered by the 4.9-litre S62 V8 engine. It was the first M5 model to be powered by a V8 engine.
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  • 05 Dec 2022
Topic Review
Aarne–Thompson Classification Systems
The Aarne–Thompson classification systems are indices used to classify folktales: the Aarne–Thompson Motif-Index (catalogued by alphabetical letters followed by numerals), the Aarne–Thompson Tale Type Index (cataloged by AT or AaTh numbers), and the Aarne–Thompson–Uther classification system (developed in 2004 and cataloged by ATU numbers). They are named after their authors, Antti Aarne, Stith Thompson, and Hans-Jörg Uther. The indices are used in folkloristics to organize, classify, and analyze folklore narratives and are essential tools for folklorists, as Alan Dundes explained in 1997 about the first two indices, "the identification of folk narratives through motif and/or tale type numbers has become an international sine qua non among bona fide folklorists".
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  • 05 Dec 2022
Topic Review
1888–1893 Uprisings of Hazaras
The 1888–1893 Uprisings of Hazaras occurred in the aftermath of the Second Anglo-Afghan War, when the Afghan Emirate signed the Treaty of Gandamak. Afghan King Abdur Rahman Khan set out to bring the Turkistan, Hazarajat and Kafiristan regions under his control. He launched several campaigns in the Hazarajat due to resistance from the Hazaras, and he conducted a widespread campaign on its population. Over sixty percent of the total Hazara population was killed with some being displaced by fleeing to Quetta and other adjoining areas. The Hazara land was distributed among loyalist villagers of nearby non-Hazaras. Moreover, many Hazaras were sold in the markets of Kabul and Qandahar. Abdur Rahman arrested Syed Jafar, chief of the Sheikh Ali Hazara tribe, and jailed him in Mazar-e-Sharif. The repression after the uprising has been called the most significant case of genocide or ethnic cleansing in the history of modern Afghanistan.
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  • 05 Dec 2022
Topic Review
Transmission Electron Microscopy
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a scintillator attached to a charge-coupled device. Transmission electron microscopes are capable of imaging at a significantly higher resolution than light microscopes, owing to the smaller de Broglie wavelength of electrons. This enables the instrument to capture fine detail—even as small as a single column of atoms, which is thousands of times smaller than a resolvable object seen in a light microscope. Transmission electron microscopy is a major analytical method in the physical, chemical and biological sciences. TEMs find application in cancer research, virology, and materials science as well as pollution, nanotechnology and semiconductor research, but also in other fields such as paleontology and palynology. TEM instruments have multiple operating modes including conventional imaging, scanning TEM imaging (STEM), diffraction, spectroscopy, and combinations of these. Even within conventional imaging, there are many fundamentally different ways that contrast is produced, called "image contrast mechanisms". Contrast can arise from position-to-position differences in the thickness or density ("mass-thickness contrast"), atomic number ("Z contrast", referring to the common abbreviation Z for atomic number), crystal structure or orientation ("crystallographic contrast" or "diffraction contrast"), the slight quantum-mechanical phase shifts that individual atoms produce in electrons that pass through them ("phase contrast"), the energy lost by electrons on passing through the sample ("spectrum imaging") and more. Each mechanism tells the user a different kind of information, depending not only on the contrast mechanism but on how the microscope is used—the settings of lenses, apertures, and detectors. What this means is that a TEM is capable of returning an extraordinary variety of nanometer- and atomic-resolution information, in ideal cases revealing not only where all the atoms are but what kinds of atoms they are and how they are bonded to each other. For this reason TEM is regarded as an essential tool for nanoscience in both biological and materials fields. The first TEM was demonstrated by Max Knoll and Ernst Ruska in 1931, with this group developing the first TEM with resolution greater than that of light in 1933 and the first commercial TEM in 1939. In 1986, Ruska was awarded the Nobel Prize in physics for the development of transmission electron microscopy.
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  • 05 Dec 2022
Topic Review
Near-Earth Object Surveillance Mission
The Near-Earth Object Surveillance Mission (NEOSM), formerly called Near-Earth Object Camera (NEOCam) is a planned space-based infrared telescope designed to survey the Solar System for potentially hazardous asteroids. The NEO Surveillance Mission will be carried out by the NEO Surveyor spacecraft, which will survey from the Sun–Earth L1 (inner) Lagrange point, allowing it to look close to the Sun and see objects inside Earth's orbit. The mission will be a successor to the NEOWISE mission; the principal investigator is also NEOWISE's principal investigator, Amy Mainzer at the University of Arizona. Since first proposed in 2006, the concept unsuccessfully competed repeatedly for NASA funding against science missions unrelated to planetary defense, despite a 2005 US Congressional directive to NASA. In 2019, it was decided to implement this mission by the Planetary Defense Coordination Office since it is a public safety issue. The Jet Propulsion Laboratory will lead development of the mission.
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  • 05 Dec 2022
Topic Review
African Bush Elephant
The African bush elephant (Loxodonta africana), also known as the African savanna elephant, is the largest living terrestrial animal with bulls reaching a shoulder height of up to 3.96 m (13.0 ft). Both sexes have tusks, which erupt when they are 1–3 years old and grow throughout life. It is distributed across 37 African countries and inhabits forests, grasslands and woodlands, wetlands and agricultural land. Since 2004, it has been listed as Vulnerable on the IUCN Red List. It is threatened foremost by habitat destruction, and in parts of its range also by poaching for meat and ivory. It is a social mammal, traveling in herds composed of cows and their offspring. Adult bulls usually live alone or in small bachelor groups. It is a herbivore, feeding on grasses, creepers, herbs, leaves and bark.
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  • 05 Dec 2022
Topic Review
Astronomy
Astronomy (from grc ἀστρονομία (Script error: No such module "Ancient Greek".) 'science that studies the laws of the stars') is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Nowadays, professional astronomy is often said to be the same as astrophysics. Professional astronomy is split into observational and theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects. This data is then analyzed using basic principles of physics. Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. These two fields complement each other. Theoretical astronomy seeks to explain observational results and observations are used to confirm theoretical results. Astronomy is one of the few sciences in which amateurs play an active role. This is especially true for the discovery and observation of transient events. Amateur astronomers have helped with many important discoveries, such as finding new comets.
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  • 05 Dec 2022
Topic Review
Literacy
Literacy is traditionally defined as the ability to read and write. In the modern world, this is one way of interpreting literacy. A more broad interpretation is literacy as knowledge and competence in a specific area. The concept of literacy has evolved in meaning. The modern term's meaning has been expanded to include the ability to use language, numbers, images, computers, and other basic means to understand, communicate, gain useful knowledge, solve mathematical problems and use the dominant symbol systems of a culture. The concept of literacy is expanding across OECD countries to include skills to access knowledge through technology and ability to assess complex contexts. A person who travels and resides in a foreign country but is unable to read or write in the language of the host country would also be regarded by the locals as illiterate. The key to literacy is reading development, a progression of skills that begins with the ability to understand spoken words and decode written words, and culminates in the deep understanding of text. Reading development involves a range of complex language underpinnings including awareness of speech sounds (phonology), spelling patterns (orthography), word meaning (semantics), grammar (syntax) and patterns of word formation (morphology), all of which provide a necessary platform for reading fluency and comprehension. Once these skills are acquired, the reader can attain full language literacy, which includes the abilities to apply to printed material critical analysis, inference and synthesis; to write with accuracy and coherence; and to use information and insights from text as the basis for informed decisions and creative thought. The inability to do so is called illiteracy or analphabetism. The United Nations Educational, Scientific and Cultural Organization (UNESCO) defines literacy as the "ability to identify, understand, interpret, create, communicate and compute, using printed and written materials associated with varying contexts. Literacy involves a continuum of learning in enabling individuals to achieve their goals, to develop their knowledge and potential, and to participate fully in their community and wider society".
  • 8.3K
  • 05 Dec 2022
Topic Review
Middle Eastern Philosophy
Middle Eastern philosophy includes the various philosophies of the Middle East regions, including the Fertile Crescent, Iran, and Anatolia. Traditions include Ancient Egyptian philosophy, Babylonian philosophy, Jewish philosophy, Iranian/Persian philosophy, and Islamic philosophy.
  • 4.4K
  • 05 Dec 2022
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