id stringlengths 2 8 | url stringlengths 31 117 | title stringlengths 1 71 | text stringlengths 153 118k | topic stringclasses 4
values | section stringlengths 4 49 ⌀ | sublist stringclasses 9
values |
|---|---|---|---|---|---|---|
451781 | https://en.wikipedia.org/wiki/Polyacrylonitrile | Polyacrylonitrile | Polyacrylonitrile (PAN) is a synthetic, semicrystalline organic polymer resin, with the linear formula (CH2CHCN)n. Almost all PAN resins are copolymers with acrylonitrile as the main monomer. PAN is used to produce large variety of products including ultra filtration membranes, hollow fibers for reverse osmosis, fibe... | Physical sciences | Polymers | Chemistry |
451839 | https://en.wikipedia.org/wiki/MESSENGER | MESSENGER | MESSENGER was a NASA robotic space probe that orbited the planet Mercury between 2011 and 2015, studying Mercury's chemical composition, geology, and magnetic field. The name is a backronym for Mercury Surface, Space Environment, Geochemistry, and Ranging, and a reference to the messenger god Mercury from Roman mythol... | Technology | Unmanned spacecraft | null |
17275317 | https://en.wikipedia.org/wiki/Anthoxanthin | Anthoxanthin | Anthoxanthins (flavones and flavonols) are a type of flavonoid pigments in plants. Anthoxanthins are water-soluble pigments which range in color from white or colorless to a creamy to yellow, often on petals of flowers. These pigments are generally whiter in an acid medium and yellowed in an alkaline medium. They are ... | Physical sciences | Polyphenols | Chemistry |
2527306 | https://en.wikipedia.org/wiki/Patagona | Patagona | The giant hummingbirds are hummingbirds of the genus Patagona. The genus includes two species, the sedentary giant hummingbird and the migratory giant hummingbird, which are the largest and second largest species of hummingbird respectively.
Taxonomy
The giant hummingbird was described and illustrated in 1824 by the ... | Biology and health sciences | Apodiformes | Animals |
2527382 | https://en.wikipedia.org/wiki/Paleothermometer | Paleothermometer | A paleothermometer is a methodology that provides an estimate of the ambient temperature at the time of formation of a natural material. Most paleothermometers are based on empirically-calibrated proxy relationships, such as the tree ring or TEX86 methods. Isotope methods, such as the δ18O method or the clumped-isotope... | Physical sciences | Paleoclimate | Earth science |
2528595 | https://en.wikipedia.org/wiki/Russet%20Burbank | Russet Burbank | Russet Burbank is a potato cultivar with dark brown skin and few eyes that is the most widely grown potato in North America. A russet type, its flesh is white, dry, and mealy, and it is good for baking, mashing, and french fries (chips). It is a common and popular potato.
Origin
This variety is a mutation (or sport) o... | Biology and health sciences | Root vegetables | Plants |
2532789 | https://en.wikipedia.org/wiki/Standard%20gravity | Standard gravity | The standard acceleration of gravity or standard acceleration of free fall, often called simply standard gravity and denoted by or , is the nominal gravitational acceleration of an object in a vacuum near the surface of the Earth. It is a constant defined by standard as . This value was established by the third Genera... | Physical sciences | Acceleration | Basics and measurement |
19469852 | https://en.wikipedia.org/wiki/Plane%20%28mathematics%29 | Plane (mathematics) | In mathematics, a plane is a two-dimensional space or flat surface that extends indefinitely.
A plane is the two-dimensional analogue of a point (zero dimensions), a line (one dimension) and three-dimensional space. When working exclusively in two-dimensional Euclidean space, the definite article is used, so the Eucli... | Mathematics | Geometry | null |
19480112 | https://en.wikipedia.org/wiki/Arctic%20methane%20emissions | Arctic methane emissions | Arctic methane emissions contribute to a rise in methane concentrations in the atmosphere. Whilst the Arctic region is one of many natural sources of the greenhouse gas methane, there is nowadays also a human component to this due to the effects of climate change. In the Arctic, the main human-influenced sources of met... | Physical sciences | Climate change | Earth science |
19480890 | https://en.wikipedia.org/wiki/Law%20of%20cosines | Law of cosines | In trigonometry, the law of cosines (also known as the cosine formula or cosine rule) relates the lengths of the sides of a triangle to the cosine of one of its angles. For a triangle with sides and opposite respective angles and (see Fig. 1), the law of cosines states:
The law of cosines generalizes the Pythago... | Mathematics | Trigonometry | null |
10428984 | https://en.wikipedia.org/wiki/Tourniquet | Tourniquet | A tourniquet is a device that is used to apply pressure to a limb or extremity in order to create ischemia or stopping the flow of blood. It may be used in emergencies, in surgery, or in post-operative rehabilitation.
A simple tourniquet can be made from a stick and a rope, but the use of makeshift tourniquets has bee... | Technology | Devices | null |
18468102 | https://en.wikipedia.org/wiki/Dead%20leaf%20mantis | Dead leaf mantis | Dead leaf mantis is a common name given to various species of praying mantis that mimic dead leaves. It is most often used in reference to species within genus Deroplatys because of their popularity as exotic pets. Examples include D. desiccata (giant dead leaf mantis), D. lobata (Southeast Asian dead leaf mantis), a... | Biology and health sciences | Insects: General | Animals |
18471728 | https://en.wikipedia.org/wiki/Agricultural%20land | Agricultural land | Agricultural land is typically land devoted to agriculture, the systematic and controlled use of other forms of lifeparticularly the rearing of livestock and production of cropsto produce food for humans. It is generally synonymous with both farmland or cropland, as well as pasture or rangeland.
The United Nations Foo... | Technology | Basics_2 | null |
3476955 | https://en.wikipedia.org/wiki/Shear%20%28geology%29 | Shear (geology) | In geology, shear is the response of a rock to deformation usually by compressive stress and forms particular textures. Shear can be homogeneous or non-homogeneous, and may be pure shear or simple shear. Study of geological shear is related to the study of structural geology, rock microstructure or rock texture and fa... | Physical sciences | Structural geology | Earth science |
3479667 | https://en.wikipedia.org/wiki/Parton%20%28particle%20physics%29 | Parton (particle physics) | In particle physics, the parton model is a model of hadrons, such as protons and neutrons, proposed by Richard Feynman. It is useful for interpreting the cascades of radiation (a parton shower) produced from quantum chromodynamics (QCD) processes and interactions in high-energy particle collisions.
History
The parton ... | Physical sciences | Subatomic particles: General | Physics |
3482079 | https://en.wikipedia.org/wiki/Sodium%20orthovanadate | Sodium orthovanadate | Sodium orthovanadate is the inorganic compound with the chemical formula . It forms a dihydrate . Sodium orthovanadate is a salt of the oxyanion. It is a colorless, water-soluble solid.
Synthesis and structure
Sodium orthovanadate is produced by dissolving vanadium(V) oxide in a solution of sodium hydroxide:
The sal... | Physical sciences | Metallic oxyanions | Chemistry |
3482374 | https://en.wikipedia.org/wiki/Military%20glider | Military glider | Military gliders (an offshoot of common gliders) have been used by the militaries of various countries for carrying troops (glider infantry) and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transpo... | Technology | Military aviation | null |
757240 | https://en.wikipedia.org/wiki/Plastic%20mulch | Plastic mulch | Plastic mulch is a product used in plasticulture in a similar fashion to mulch, to suppress weeds and conserve water in crop production and landscaping. Certain plastic mulches also act as a barrier to keep methyl bromide, both a powerful fumigant and ozone depleter, in the soil. Crops grow through slits or holes in th... | Technology | Soil and soil management | null |
757361 | https://en.wikipedia.org/wiki/EuroVelo | EuroVelo | EuroVelo is a network of 17 long-distance cycling routes criss-crossing Europe, with 2 more in early construction across various stages of completion. When completed, the EuroVelo network's total length will be almost . more than were in place. EuroVelo is a project of the European Cyclists' Federation (ECF). The mul... | Technology | Ground transportation networks | null |
758445 | https://en.wikipedia.org/wiki/Baler | Baler | A baler or hay baler is a piece of farm machinery used to compress a cut and raked crop (such as hay, cotton, flax straw, salt marsh hay, or silage) into compact bales that are easy to handle, transport, and store. Often, bales are configured to dry and preserve some intrinsic (e.g. the nutritional) value of the plan... | Technology | Farm and garden machinery | null |
758833 | https://en.wikipedia.org/wiki/Past | Past | The past is the set of all events that occurred before a given point in time. The past is contrasted with and defined by the present and the future. The concept of the past is derived from the linear fashion in which human observers experience time, and is accessed through memory and recollection. In addition, human be... | Technology | Timekeeping | null |
759008 | https://en.wikipedia.org/wiki/Eye%20color | Eye color | Eye color is a polygenic phenotypic trait determined by two factors: the pigmentation of the eye's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.
In humans, the pigmentation of the iris varies from light brown to black, depending on the concentration of mel... | Biology and health sciences | Visual system | Biology |
759071 | https://en.wikipedia.org/wiki/Noctilucent%20cloud | Noctilucent cloud | Noctilucent clouds (NLCs), or night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth. When viewed from space, they are called polar mesospheric clouds (PMCs), detectable as a diffuse scattering layer of water ice crystals near the summer polar mesopause. They consist of ice crystals and... | Physical sciences | Clouds | Earth science |
759264 | https://en.wikipedia.org/wiki/Amount%20of%20substance | Amount of substance | In chemistry, the amount of substance (symbol ) in a given sample of matter is defined as a ratio () between the number of elementary entities () and the Avogadro constant (). The entities are usually molecules, atoms, ions, or ion pairs of a specified kind. The particular substance sampled may be specified using a sub... | Physical sciences | Chemistry: General | null |
8082793 | https://en.wikipedia.org/wiki/Breakdown%20%28vehicle%29 | Breakdown (vehicle) | A vehicle breakdown is a mechanical or electrical failure of a motor vehicle in such a way that the underlying problem prevents the vehicle from being operated or impedes the vehicle's operation so significantly that it is very difficult, nearly impossible, or else dangerous to operate.
Vehicle breakdowns have vario... | Technology | Concepts of ground transport | null |
1219865 | https://en.wikipedia.org/wiki/Panthera%20spelaea | Panthera spelaea | Panthera spelaea, commonly known as the cave lion (or less commonly as the steppe lion), is an extinct Panthera species that was native to Eurasia and northwest North America during the Pleistocene epoch. Genetic analysis of ancient DNA has revealed that while closely related, it was a distinct species genetically isol... | Biology and health sciences | Felines | Animals |
1220214 | https://en.wikipedia.org/wiki/American%20lion | American lion | The American lion (Panthera atrox (), with the species name meaning "savage" or "cruel", also called the North American lion) is an extinct pantherine cat native to North America during the Late Pleistocene from around 130,000 to 12,800 years ago. Genetic evidence suggests that its closest living relative is the lion (... | Biology and health sciences | Felines | Animals |
1221281 | https://en.wikipedia.org/wiki/Diapause | Diapause | In animal dormancy, diapause is the delay in development in response to regular and recurring periods of adverse environmental conditions. It is a physiological state with very specific initiating and inhibiting conditions. The mechanism is a means of surviving predictable, unfavorable environmental conditions, such as... | Biology and health sciences | Ethology | Biology |
1221466 | https://en.wikipedia.org/wiki/Coulometry | Coulometry | In analytical electrochemistry, coulometry is the measure of charge (coulombs) transfer during an electrochemical redox reaction. It can be used for precision measurements of charge, but coulometry is mainly used for analytical applications to determine the amount of matter transformed.
There are two main categories ... | Physical sciences | Electrical methods | Chemistry |
1222028 | https://en.wikipedia.org/wiki/Pine%20tar | Pine tar | Pine tar is a form of wood tar produced by the high temperature carbonization of pine wood in anoxic conditions (dry distillation or destructive distillation). The wood is rapidly decomposed by applying heat and pressure in a closed container; the primary resulting products are charcoal and pine tar.
Pine tar consists... | Physical sciences | Hydrocarbons | Chemistry |
6135482 | https://en.wikipedia.org/wiki/Juniper%20berry | Juniper berry | A juniper berry is the female seed cone produced by the various species of junipers. It is not a true berry but a cone with unusually fleshy and merged scales called a galbulus, which gives it a berry-like appearance. The cones from a handful of species, especially Juniperus communis, are used as a spice, particularly ... | Biology and health sciences | Cupressaceae | Plants |
6139438 | https://en.wikipedia.org/wiki/Formation%20and%20evolution%20of%20the%20Solar%20System | Formation and evolution of the Solar System | There is evidence that the formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons... | Physical sciences | Physical cosmology | null |
6139788 | https://en.wikipedia.org/wiki/Bending%20%28metalworking%29 | Bending (metalworking) | Bending is a manufacturing process that produces a V-shape, U-shape, or channel shape along a straight axis in ductile materials, most commonly sheet metal. Commonly used equipment include box and pan brakes, brake presses, and other specialized machine presses. Typical products that are made like this are boxes such a... | Technology | Metallurgy | null |
22161339 | https://en.wikipedia.org/wiki/Myxogastria | Myxogastria | Myxogastria/Myxogastrea (myxogastrids, ICZN) or Myxomycetes (ICN) is a class of slime molds that contains 5 orders, 14 families, 62 genera, and 888 species. They are colloquially known as the plasmodial or acellular slime moulds.
All species pass through several very different morphologic phases, such as microscopic i... | Biology and health sciences | Eukaryotes | Plants |
10432749 | https://en.wikipedia.org/wiki/Pacific%20bluefin%20tuna | Pacific bluefin tuna | The Pacific bluefin tuna (Thunnus orientalis) is a predatory species of tuna found widely in the northern Pacific Ocean, but it is migratory and also recorded as a visitor to the south Pacific.
In the past it was often included in T. thynnus, the 'combined' species then known as the northern bluefin tuna (when treated... | Biology and health sciences | Acanthomorpha | Animals |
12743856 | https://en.wikipedia.org/wiki/Polymer%20engineering | Polymer engineering | Polymer engineering is generally an engineering field that designs, analyses, and modifies polymer materials. Polymer engineering covers aspects of the petrochemical industry, polymerization, structure and characterization of polymers, properties of polymers, compounding and processing of polymers and description of ma... | Technology | Disciplines | null |
20686278 | https://en.wikipedia.org/wiki/Lobaria%20pulmonaria | Lobaria pulmonaria | Lobaria pulmonaria is a large epiphytic lichen consisting of an ascomycete fungus and a green algal partner living together in a symbiotic relationship with a cyanobacterium—a symbiosis involving members of three kingdoms of organisms. Commonly known by various names like tree lungwort, lung lichen, lung moss, lungwort... | Biology and health sciences | Lichens | Plants |
1827237 | https://en.wikipedia.org/wiki/Factorial%20experiment | Factorial experiment | In statistics, a full factorial experiment is an experiment whose design consists of two or more factors, each with discrete possible values or "levels", and whose experimental units take on all possible combinations of these levels across all such factors. A full factorial design may also be called a fully crossed des... | Mathematics | Statistics | null |
1827682 | https://en.wikipedia.org/wiki/Male%20reproductive%20system | Male reproductive system | The male reproductive system consists of a number of sex organs that play a role in the process of human reproduction. These organs are located on the outside of the body, and within the pelvis.
The main male sex organs are the penis and the scrotum, which contains the testicles that produce semen and sperm, which, as... | Biology and health sciences | Reproductive system | null |
1828131 | https://en.wikipedia.org/wiki/Davisson%E2%80%93Germer%20experiment | Davisson–Germer experiment | The Davisson–Germer experiment was a 1923–1927 experiment by Clinton Davisson and Lester Germer at Western Electric (later Bell Labs), in which electrons, scattered by the surface of a crystal of nickel metal, displayed a diffraction pattern. This confirmed the hypothesis, advanced by Louis de Broglie in 1924, of wave-... | Physical sciences | Quantum mechanics | Physics |
1828559 | https://en.wikipedia.org/wiki/Ornithomimus | Ornithomimus | Ornithomimus (; "bird mimic") is a genus of ornithomimid theropod dinosaurs from the Campanian and Maastrichtian ages of Late Cretaceous Western North America. Ornithomimus was a swift, bipedal dinosaur which fossil evidence indicates was covered in feathers and equipped with a small toothless beak that may indicate an... | Biology and health sciences | Theropods | Animals |
1828723 | https://en.wikipedia.org/wiki/Neomycin/polymyxin%20B/bacitracin | Neomycin/polymyxin B/bacitracin | Neomycin/polymyxin B/bacitracin, also known as triple antibiotic ointment, is an antibiotic medication used to reduce the risk of infections following minor skin injuries. It contains the three antibiotics neomycin, polymyxin B, and bacitracin. It is for topical use.
Possible side effects include itchiness and skin ra... | Biology and health sciences | Antibiotics | Health |
1829229 | https://en.wikipedia.org/wiki/Padlock | Padlock | Padlocks are portable locks with a shackle that may be passed through an opening (such as a chain link, or hasp staple) to prevent use, theft, vandalism or harm.
Naming and etymology
The term padlock is from the late fifteenth century. The prefix pad- is thought to be related to the Latin which may refer to the porta... | Technology | Mechanisms | null |
1830142 | https://en.wikipedia.org/wiki/Bijection%2C%20injection%20and%20surjection | Bijection, injection and surjection | In mathematics, injections, surjections, and bijections are classes of functions distinguished by the manner in which arguments (input expressions from the domain) and images (output expressions from the codomain) are related or mapped to each other.
A function maps elements from its domain to elements in its codomain... | Mathematics | Functions: General | null |
4685590 | https://en.wikipedia.org/wiki/Optical%20path | Optical path | Optical path (OP) is the trajectory that a light ray follows as it propagates through an optical medium.
The geometrical optical-path length or simply geometrical path length (GPD) is the length of a segment in a given OP, i.e., the Euclidean distance integrated along a ray between any two points.
The mechanical length... | Physical sciences | Optics | Physics |
4687085 | https://en.wikipedia.org/wiki/Streamflow | Streamflow | Streamflow, or channel runoff, is the flow of water in streams and other channels, and is a major element of the water cycle. It is one runoff component, the movement of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hillsl... | Physical sciences | Hydrology | Earth science |
4688195 | https://en.wikipedia.org/wiki/Astigmatism | Astigmatism | Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. This results in distorted or blurred vision at any distance. Other symptoms can include eyestrain, headaches, and trouble driving at night. Astigmatism often occurs at birth and can change or develop later in life. If ... | Biology and health sciences | Disabilities | Health |
4689328 | https://en.wikipedia.org/wiki/TNT%20equivalent | TNT equivalent | TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. The is a unit of energy defined by convention to be (), which is the approximate energy released in the detonation of a metric ton (1,000 kilograms) of TNT. In other words, for each gram of TNT explod... | Physical sciences | Energy | Basics and measurement |
4691461 | https://en.wikipedia.org/wiki/Rotterdam%20Metro | Rotterdam Metro | The Rotterdam Metro () is a rapid transit system operated in Rotterdam, Netherlands and surrounding municipalities by RET. The first line, called Noord – Zuidlijn (North – South line) opened in 1968 and ran from Centraal Station to Zuidplein, crossing the river Nieuwe Maas in a tunnel. It was the first metro system to ... | Technology | Netherlands | null |
4692188 | https://en.wikipedia.org/wiki/Two-toed%20sloth | Two-toed sloth | Choloepus is a genus of xenarthran mammals from Central and South America within the monotypic family Choloepodidae, consisting of two-toed sloths, sometimes also called two-fingered sloths. The two species of Choloepus (which means "lame foot" in Ancient Greek), Linnaeus's two-toed sloth (Choloepus didactylus) and Hof... | Biology and health sciences | Xenarthra | Animals |
4692632 | https://en.wikipedia.org/wiki/Portrait%20photography | Portrait photography | Portrait photography, or portraiture, is a type of photography aimed toward capturing the personality of a person or group of people by using effective lighting, backdrops, and poses. A portrait photograph may be artistic or clinical. Frequently, portraits are commissioned for special occasions, such as weddings, schoo... | Technology | Photography | null |
4693311 | https://en.wikipedia.org/wiki/Thiosulfate | Thiosulfate | Thiosulfate (IUPAC-recommended spelling; sometimes thiosulphate in British English) is an oxyanion of sulfur with the chemical formula . Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, such as sodium thiosulfate and ammonium thiosulfate . Thiosulfate salts occ... | Physical sciences | Sulfuric oxyanions | Chemistry |
8088857 | https://en.wikipedia.org/wiki/Cone%20snail | Cone snail | Cone snails, or cones, are highly venomous sea snails of the family Conidae.
Fossils of cone snails have been found from the Eocene to the Holocene epochs. Cone snail species have shells that are roughly conical in shape. Many species have colorful patterning on the shell surface. Cone snails are almost exclusively tr... | Biology and health sciences | Gastropods | Animals |
246747 | https://en.wikipedia.org/wiki/Giant%20salamander | Giant salamander | The Cryptobranchidae (commonly known as giant salamanders) are a family of large salamanders that are fully aquatic. The family includes some of the largest living amphibians. They are native to China, Japan, and the eastern United States. Giant salamanders constitute one of two living families—the other being the Asia... | Biology and health sciences | Salamanders and newts | Animals |
246806 | https://en.wikipedia.org/wiki/Ruminant | Ruminant | Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The process, which takes place in the front part of the digestive ... | Biology and health sciences | Artiodactyla | null |
246828 | https://en.wikipedia.org/wiki/Forage | Forage | Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term forage has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animal... | Technology | Animal husbandry | null |
246940 | https://en.wikipedia.org/wiki/Malvaceae | Malvaceae | Malvaceae (), or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include okra, cotton, cacao, roselle and durian. There are also some genera containing familiar ornamentals, such as Alcea (hollyhock), Malva (mallow), and Til... | Biology and health sciences | Others | null |
247151 | https://en.wikipedia.org/wiki/Mimicry | Mimicry | In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simplest case, as in Batesian mimicry, a mimic resembles a model, so as to deceive a d... | Biology and health sciences | Basics_2 | Biology |
247216 | https://en.wikipedia.org/wiki/Amaranthaceae | Amaranthaceae | Amaranthaceae ( ) is a family of flowering plants commonly known as the amaranth family, in reference to its type genus Amaranthus. It includes the former goosefoot family Chenopodiaceae and contains about 165 genera and 2,040 species, making it the most species-rich lineage within its parent order, Caryophyllales.
De... | Biology and health sciences | Caryophyllales | Plants |
247323 | https://en.wikipedia.org/wiki/Stirling%20cycle | Stirling cycle | The Stirling cycle is a thermodynamic cycle that describes the general class of Stirling devices. This includes the original Stirling engine that was invented, developed and patented in 1816 by Robert Stirling with help from his brother, an engineer.
The ideal Otto and Diesel cycles are not totally reversible because... | Physical sciences | Thermodynamics | Physics |
247326 | https://en.wikipedia.org/wiki/Volcanic%20glass | Volcanic glass | Volcanic glass is the amorphous (uncrystallized) product of rapidly cooling magma. Like all types of glass, it is a state of matter intermediate between the closely packed, highly ordered array of a crystal and the highly disordered array of liquid. Volcanic glass may refer to the interstitial material, or matrix, in a... | Physical sciences | Igneous rocks | Earth science |
247388 | https://en.wikipedia.org/wiki/Combine%20harvester | Combine harvester | The modern combine harvester, also called a combine, is a machine designed to harvest a variety of cultivated seeds. Combine harvesters are one of the most economically important labour-saving inventions, significantly reducing the fraction of the population engaged in agriculture. Among the crops harvested with a comb... | Technology | Farm and garden machinery | null |
247405 | https://en.wikipedia.org/wiki/Crossbill | Crossbill | Crossbills are birds of the genus Loxia within the finch family (Fringillidae), with six species. These birds are characterized by the mandibles with crossed tips, which gives the group its English name. Adult males tend to be red or orange in color, and females green or yellow, but there is much variation.
Crossbills... | Biology and health sciences | Passerida | Animals |
247410 | https://en.wikipedia.org/wiki/Cynodontia | Cynodontia | Cynodontia () is a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Mammals are cynodonts, as are their extinct ancestors and close relatives (Mammaliaformes), having evolved from advanced probainog... | Biology and health sciences | Proto-mammals | Animals |
247414 | https://en.wikipedia.org/wiki/Y-chromosomal%20Adam | Y-chromosomal Adam | In human genetics, the Y-chromosomal Adam (more technically known as the Y-chromosomal most recent common ancestor, shortened to Y-MRCA), is the patrilineal most recent common ancestor (MRCA) from whom all currently living humans are descended. He is the most recent male from whom all living humans are descended throug... | Biology and health sciences | Homo | Biology |
247577 | https://en.wikipedia.org/wiki/Graph%20isomorphism | Graph isomorphism | In graph theory, an isomorphism of graphs G and H is a bijection between the vertex sets of G and H
such that any two vertices u and v of G are adjacent in G if and only if and are adjacent in H. This kind of bijection is commonly described as "edge-preserving bijection", in accordance with the general notion of iso... | Mathematics | Graph theory | null |
247652 | https://en.wikipedia.org/wiki/Bulldog%20bat | Bulldog bat | The bat family Noctilionidae, commonly known as bulldog bats or fishing bats, is represented by two extant species, the greater and the lesser bulldog bats, as well as at least one fossil species, Noctilio lacrimaelunaris, from the Miocene of Argentina. The naked bulldog bat (Cheiromeles torquatus) does not belong to t... | Biology and health sciences | Bats | Animals |
247827 | https://en.wikipedia.org/wiki/Gar | Gar | Gars are an ancient group of ray-finned fish in the family Lepisosteidae. They comprise seven living species of fish in two genera that inhabit fresh, brackish, and occasionally marine waters of eastern North America, Central America and Cuba in the Caribbean, though extinct members of the family were more widespread. ... | Biology and health sciences | Holosteans | Animals |
247844 | https://en.wikipedia.org/wiki/Midnight | Midnight | Midnight is the transition time from one day to the next – the moment when the date changes, on the local official clock time for any particular jurisdiction. By clock time, midnight is the opposite of noon, differing from it by 12 hours.
Solar midnight is the time opposite to solar noon, when the Sun is closest to t... | Physical sciences | Celestial mechanics | Astronomy |
247989 | https://en.wikipedia.org/wiki/Lactobacillus%20delbrueckii%20subsp.%20bulgaricus | Lactobacillus delbrueckii subsp. bulgaricus | Lactobacillus bulgaricus is the main bacterium used for the production of yogurt. It also plays a crucial role in the ripening of some cheeses, as well as in other processes involving naturally fermented products. It is defined as homofermentive lactic acid bacteria due to lactic acid being the single end product of i... | Biology and health sciences | Gram-positive bacteria | Plants |
248071 | https://en.wikipedia.org/wiki/Solidago | Solidago | Solidago, commonly called goldenrods, is a genus of about 100 to 120 species of flowering plants in the family Asteraceae. Most are herbaceous perennial species found in open areas such as meadows, prairies, and savannas. They are mostly native to North America, including Mexico; a few species are native to South Ameri... | Biology and health sciences | Asterales | null |
248135 | https://en.wikipedia.org/wiki/Azide | Azide | In chemistry, azide (, ) is a linear, polyatomic anion with the formula and structure . It is the conjugate base of hydrazoic acid . Organic azides are organic compounds with the formula , containing the azide functional group. The dominant application of azides is as a propellant in air bags.
Preparation
Sodium azi... | Physical sciences | Nitride salts | Chemistry |
248189 | https://en.wikipedia.org/wiki/Gaia%20hypothesis | Gaia hypothesis | The Gaia hypothesis (), also known as the Gaia theory, Gaia paradigm, or the Gaia principle, proposes that living organisms interact with their inorganic surroundings on Earth to form a synergistic and self-regulating complex system that helps to maintain and perpetuate the conditions for life on the planet.
The Gaia ... | Physical sciences | Earth science basics: General | Earth science |
248234 | https://en.wikipedia.org/wiki/Booby%20trap | Booby trap | A booby trap is a device or setup that is intended to kill, harm or surprise a human or another animal. It is triggered by the presence or actions of the victim and sometimes has some form of bait designed to lure the victim towards it. The trap may be set to act upon trespassers that enter restricted areas, and it can... | Technology | Military technology: General | null |
248446 | https://en.wikipedia.org/wiki/Hartsfield%E2%80%93Jackson%20Atlanta%20International%20Airport | Hartsfield–Jackson Atlanta International Airport | Hartsfield–Jackson Atlanta International Airport is the primary international airport serving Atlanta and its surrounding metropolitan area, in the U.S. state of Georgia. The airport is located south of the Downtown Atlanta district. It is named after former Atlanta mayors William B. Hartsfield and Maynard Jackson. T... | Technology | North America | null |
248457 | https://en.wikipedia.org/wiki/Hong%20Kong%20International%20Airport | Hong Kong International Airport | Hong Kong International Airport is an international airport on the island of Chek Lap Kok in western Hong Kong. The airport is also referred to as Chek Lap Kok International Airport or Chek Lap Kok Airport, to distinguish it from its predecessor, the former Kai Tak Airport.
Opened in 1998, Hong Kong International Air... | Technology | Asia | null |
248669 | https://en.wikipedia.org/wiki/Tapir | Tapir | Tapirs ( ) are large, herbivorous mammals belonging to the family Tapiridae. They are similar in shape to a pig, with a short, prehensile nose trunk. Tapirs inhabit jungle and forest regions of South and Central America and Southeast Asia. They are one of three extant branches of Perissodactyla (odd-toed ungulates), al... | Biology and health sciences | Perissodactyla | null |
248671 | https://en.wikipedia.org/wiki/Gluconeogenesis | Gluconeogenesis | Gluconeogenesis (GNG) is a metabolic pathway that results in the biosynthesis of glucose from certain non-carbohydrate carbon substrates. It is a ubiquitous process, present in plants, animals, fungi, bacteria, and other microorganisms. In vertebrates, gluconeogenesis occurs mainly in the liver and, to a lesser extent,... | Biology and health sciences | Metabolic processes | Biology |
248808 | https://en.wikipedia.org/wiki/Algebraic%20variety | Algebraic variety | Algebraic varieties are the central objects of study in algebraic geometry, a sub-field of mathematics. Classically, an algebraic variety is defined as the set of solutions of a system of polynomial equations over the real or complex numbers. Modern definitions generalize this concept in several different ways, while a... | Mathematics | Algebra | null |
248860 | https://en.wikipedia.org/wiki/Theodolite | Theodolite | A theodolite () is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and infrastructure construction, and some specialized applications such as meteoro... | Technology | Optical instruments | null |
248932 | https://en.wikipedia.org/wiki/Software%20development | Software development | Software development is the process of designing and implementing a software solution to satisfy a user. The process is more encompassing than programming, writing code, in that it includes conceiving the goal, evaluating feasibility, analyzing requirements, design, testing and release. The process is part of software ... | Technology | Software development: General | null |
248988 | https://en.wikipedia.org/wiki/Product%20rule | Product rule | In calculus, the product rule (or Leibniz rule or Leibniz product rule) is a formula used to find the derivatives of products of two or more functions. For two functions, it may be stated in Lagrange's notation as or in Leibniz's notation as
The rule may be extended or generalized to products of three or more functi... | Mathematics | Differential calculus | null |
249033 | https://en.wikipedia.org/wiki/Multiplication%20sign | Multiplication sign | The multiplication sign (), also known as the times sign or the dimension sign, is a mathematical symbol used to denote the operation of multiplication, which results in a product.
The symbol is also used in botany, in botanical hybrid names.
The form is properly a four-fold rotationally symmetric saltire. The mult... | Mathematics | Basics | null |
249116 | https://en.wikipedia.org/wiki/Liquorice | Liquorice | Liquorice (Commonwealth English) or licorice (American English; see spelling differences; ) is the common name of Glycyrrhiza glabra, a flowering plant of the bean family Fabaceae, from the root of which a sweet, aromatic flavouring is extracted.
The liquorice plant is an herbaceous perennial legume native to West As... | Biology and health sciences | Fabales | null |
249254 | https://en.wikipedia.org/wiki/Clique%20problem | Clique problem | In computer science, the clique problem is the computational problem of finding cliques (subsets of vertices, all adjacent to each other, also called complete subgraphs) in a graph. It has several different formulations depending on which cliques, and what information about the cliques, should be found. Common formulat... | Mathematics | Graph theory | null |
249357 | https://en.wikipedia.org/wiki/Sleepwalking | Sleepwalking | Sleepwalking, also known as somnambulism or noctambulism, is a phenomenon of combined sleep and wakefulness. It is classified as a sleep disorder belonging to the parasomnia family. It occurs during the slow wave stage of sleep, in a state of low consciousness, with performance of activities that are usually performed ... | Biology and health sciences | Mental disorders | Health |
249509 | https://en.wikipedia.org/wiki/S-Bahn | S-Bahn | The S-Bahn ( , ), , is a hybrid urban–suburban rail system serving a metropolitan region predominantly in German-speaking countries. Some of the larger S-Bahn systems provide service similar to rapid transit systems, while smaller ones often resemble commuter or even regional rail systems. The name S-Bahn derives from ... | Technology | Germany | null |
249530 | https://en.wikipedia.org/wiki/Plains%20zebra | Plains zebra | The plains zebra (Equus quagga, formerly Equus burchellii) is the most common and geographically widespread species of zebra. Its range is fragmented, but spans much of southern and eastern Africa south of the Sahara. Six or seven subspecies have been recognised, including the quagga which was thought to be a separate ... | Biology and health sciences | Equidae | Animals |
249613 | https://en.wikipedia.org/wiki/Continental%20climate | Continental climate | Continental climates often have a significant annual variation in temperature (warm to hot summers and cold winters). They tend to occur in central and eastern parts of the three northern-tier continents (North America, Europe, and Asia), typically in the middle latitudes (40 to 55 or 60 degrees north), often within la... | Physical sciences | Climates | Earth science |
249773 | https://en.wikipedia.org/wiki/Killifish | Killifish | A killifish is any of various oviparous (egg-laying) cyprinodontiform fish, including families Aplocheilidae, Cyprinodontidae, Fundulidae, Nothobranchiidae, Profundulidae, Aphaniidae and Valenciidae. All together, there are 1,270 species of killifish, the biggest family being Rivulidae, containing more than 320 species... | Biology and health sciences | Acanthomorpha | Animals |
3484275 | https://en.wikipedia.org/wiki/Dean%E2%80%93Stark%20apparatus | Dean–Stark apparatus | The Marcusson apparatus, Dean-Stark apparatus, Dean–Stark receiver, distilling trap, or Dean–Stark Head is a piece of laboratory glassware used in synthetic chemistry to collect water (or occasionally other liquid) from a reactor. It is used in combination with a reflux condenser and a distillation flask for the separ... | Physical sciences | Phase separations | Chemistry |
3486181 | https://en.wikipedia.org/wiki/Rigid%20airship | Rigid airship | A rigid airship is a type of airship (or dirigible) in which the envelope is supported by an internal framework rather than by being kept in shape by the pressure of the lifting gas within the envelope, as in blimps (also called pressure airships) and semi-rigid airships. Rigid airships are often commonly called Zeppe... | Technology | Types of aircraft | null |
3488015 | https://en.wikipedia.org/wiki/Stunted%20growth | Stunted growth | Stunted growth, also known as stunting or linear growth failure, is defined as impaired growth and development manifested by low height-for-age. It is a manifestation of malnutrition (undernutrition) and can be caused by endogenous factors (such as chronic food insecurity) or exogenous factors (such as parasitic infect... | Biology and health sciences | Health and fitness: General | Health |
3489162 | https://en.wikipedia.org/wiki/Oriental%20garden%20lizard | Oriental garden lizard | The oriental garden lizard (Calotes versicolor), also called the eastern garden lizard, Indian garden lizard, common garden lizard, bloodsucker or changeable lizard, is an agamid lizard found widely distributed in Indo-Malaya. It has also been introduced in many other parts of the world.
Description
Calotes versicolo... | Biology and health sciences | Iguania | Animals |
113079 | https://en.wikipedia.org/wiki/Winnowing | Winnowing | Winnowing is a process by which chaff is separated from grain. It can also be used to remove pests from stored grain. Winnowing usually follows threshing in grain preparation. In its simplest form, it involves throwing the mixture into the air so that the wind blows away the lighter chaff, while the heavier grains fall... | Technology | Agronomical techniques | null |
113087 | https://en.wikipedia.org/wiki/System%20of%20linear%20equations | System of linear equations | In mathematics, a system of linear equations (or linear system) is a collection of two or more linear equations involving the same variables.
For example,
is a system of three equations in the three variables . A solution to a linear system is an assignment of values to the variables such that all the equations are s... | Mathematics | Linear algebra | null |
113222 | https://en.wikipedia.org/wiki/Law%20of%20sines | Law of sines | In trigonometry, the law of sines, sine law, sine formula, or sine rule is an equation relating the lengths of the sides of any triangle to the sines of its angles. According to the law,
where , and are the lengths of the sides of a triangle, and , and are the opposite angles (see figure 2), while is the radius of ... | Mathematics | Trigonometry | null |
113262 | https://en.wikipedia.org/wiki/Diprotodontia | Diprotodontia | Diprotodontia (, from Greek "two forward teeth") is the largest extant order of marsupials, with about 155 species, including the kangaroos, wallabies, possums, koala, wombats, and many others. Extinct diprotodonts include the hippopotamus-sized Diprotodon, and Thylacoleo, the so-called "marsupial lion".
Characteristi... | Biology and health sciences | Marsupials | null |
113276 | https://en.wikipedia.org/wiki/Adze | Adze | An adze () or adz is an ancient and versatile cutting tool similar to an axe but with the cutting edge perpendicular to the handle rather than parallel. Adzes have been used since the Stone Age. They are used for smoothing or carving wood in hand woodworking, and as a hoe for agriculture and horticulture. Two basic for... | Technology | Hand tools | null |
113302 | https://en.wikipedia.org/wiki/Surface%20tension | Surface tension | Surface tension is the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as razor blades and insects (e.g. water striders) to float on a water surface without becoming even partly submerged.
At liquid–air i... | Physical sciences | Fluid mechanics | null |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.