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65907
https://en.wikipedia.org/wiki/Elastic%20collision
Elastic collision
In physics, an elastic collision is an encounter (collision) between two bodies in which the total kinetic energy of the two bodies remains the same. In an ideal, perfectly elastic collision, there is no net loss of kinetic energy into other forms such as heat, noise, or potential energy. During the collision of smal...
Physical sciences
Basics_4
Physics
65908
https://en.wikipedia.org/wiki/Inelastic%20collision
Inelastic collision
An inelastic collision, in contrast to an elastic collision, is a collision in which kinetic energy is not conserved due to the action of internal friction. In collisions of macroscopic bodies, some kinetic energy is turned into vibrational energy of the atoms, causing a heating effect, and the bodies are deformed. T...
Physical sciences
Basics_4
Physics
65910
https://en.wikipedia.org/wiki/Printed%20circuit%20board
Printed circuit board
A printed circuit board (PCB), also called printed wiring board (PWB), is a laminated sandwich structure of conductive and insulating layers, each with a pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto or between sheet laye...
Technology
Components
null
65913
https://en.wikipedia.org/wiki/Equations%20of%20motion
Equations of motion
In physics, equations of motion are equations that describe the behavior of a physical system in terms of its motion as a function of time. More specifically, the equations of motion describe the behavior of a physical system as a set of mathematical functions in terms of dynamic variables. These variables are usually ...
Physical sciences
Classical mechanics
null
65914
https://en.wikipedia.org/wiki/Kinematics
Kinematics
Kinematics is a subfield of physics and mathematics, developed in classical mechanics, that describes the motion of points, bodies (objects), and systems of bodies (groups of objects) without considering the forces that cause them to move. Kinematics, as a field of study, is often referred to as the "geometry of motion...
Physical sciences
Basics_10
null
65926
https://en.wikipedia.org/wiki/Angular%20displacement
Angular displacement
The angular displacement (symbol θ, , or φ) – also called angle of rotation, rotational displacement, or rotary displacement – of a physical body is the angle (in units of radians, degrees, turns, etc.) through which the body rotates (revolves or spins) around a centre or axis of rotation. Angular displacement may be s...
Physical sciences
Classical mechanics
Physics
65927
https://en.wikipedia.org/wiki/Angular%20velocity
Angular velocity
In physics, angular velocity (symbol or , the lowercase Greek letter omega), also known as the angular frequency vector, is a pseudovector representation of how the angular position or orientation of an object changes with time, i.e. how quickly an object rotates (spins or revolves) around an axis of rotation and how ...
Physical sciences
Classical mechanics
Physics
65929
https://en.wikipedia.org/wiki/Angular%20acceleration
Angular acceleration
In physics, angular acceleration (symbol α, alpha) is the time rate of change of angular velocity. Following the two types of angular velocity, spin angular velocity and orbital angular velocity, the respective types of angular acceleration are: spin angular acceleration, involving a rigid body about an axis of rotatio...
Physical sciences
Classical mechanics
Physics
65955
https://en.wikipedia.org/wiki/Denim
Denim
Denim is a sturdy cotton warp-faced textile in which the weft passes under two or more warp threads. This twill weave produces a diagonal ribbing that distinguishes it from cotton duck. Denim, as it is recognized today, was first produced in Nîmes, France. Denim is available in a range of colors, but the most common ...
Technology
Fabrics and fibers
null
65980
https://en.wikipedia.org/wiki/Jaundice
Jaundice
Jaundice, also known as icterus, is a yellowish or greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults is typically a sign indicating the presence of underlying diseases involving abnormal heme metabolism, liver dysfunction, or biliary-tract obstruction. The prevalence of jaund...
Biology and health sciences
Symptoms and signs
Health
66013
https://en.wikipedia.org/wiki/Field%20gun
Field gun
A field gun is a field artillery piece. Originally the term referred to smaller guns that could accompany a field army on the march, that when in combat could be moved about the battlefield in response to changing circumstances (field artillery), as opposed to guns installed in a fort (garrison artillery or coastal art...
Technology
Artillery
null
66014
https://en.wikipedia.org/wiki/Pascal%20%28unit%29
Pascal (unit)
The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an SI coherent derived unit defined as one newton per square metre (N/m2). It is also ...
Physical sciences
Energy, power, force and pressure
null
66109
https://en.wikipedia.org/wiki/Eclipse%20cycle
Eclipse cycle
Eclipses may occur repeatedly, separated by certain intervals of time: these intervals are called eclipse cycles. The series of eclipses separated by a repeat of one of these intervals is called an eclipse series. Eclipse conditions Eclipses may occur when Earth and the Moon are aligned with the Sun, and the shadow...
Physical sciences
Celestial mechanics
Astronomy
66111
https://en.wikipedia.org/wiki/Saros%20%28astronomy%29
Saros (astronomy)
The saros () is a period of exactly 223 synodic months, approximately 6585.321 days (18.04 years), or 18 years plus 10, 11, or 12 days (depending on the number of leap years), and 8 hours, that can be used to predict eclipses of the Sun and Moon. One saros period after an eclipse, the Sun, Earth, and Moon return to app...
Physical sciences
Celestial mechanics
Astronomy
66152
https://en.wikipedia.org/wiki/Sea%20urchin
Sea urchin
Sea urchins or urchins () are typically spiny, globular animals, echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal to . Their tests (hard shells) are round and spiny, typically from across. Sea urchins move slowly, crawling with their t...
Biology and health sciences
Echinoderms
null
66159
https://en.wikipedia.org/wiki/Alfalfa
Alfalfa
Alfalfa () (Medicago sativa), also called lucerne, is a perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, and silage, as well as a green manure and cover crop. The name alfalfa is used in North America. ...
Biology and health sciences
Pulses
Plants
66173
https://en.wikipedia.org/wiki/Common%20swift
Common swift
The common swift (Apus apus) is a medium-sized bird, superficially similar to the barn swallow or house martin but somewhat larger, though not stemming from those passerine species, being in the order Apodiformes. The resemblances between the groups are due to convergent evolution, reflecting similar contextual develop...
Biology and health sciences
Apodiformes
Animals
66174
https://en.wikipedia.org/wiki/Barn%20swallow
Barn swallow
The barn swallow (Hirundo rustica) is the most widespread species of swallow in the world, occurring on all continents, with vagrants reported even in Antarctica. It is a distinctive passerine bird with blue upperparts and a long, deeply forked tail. In Anglophone Europe, it is just called the swallow; in northern Euro...
Biology and health sciences
Passerida
Animals
66269
https://en.wikipedia.org/wiki/Chloride
Chloride
The term chloride refers to a compound or molecule that contains either a chlorine anion (), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (). Many inorganic chlorides are salts. Many organic compounds are chlorides. The pronu...
Physical sciences
Salts
null
66275
https://en.wikipedia.org/wiki/Coati
Coati
Coatis (from Tupí), also known as coatimundis (), are members of the family Procyonidae in the genera Nasua and Nasuella (comprising the subtribe Nasuina). They are diurnal mammals native to South America, Central America, Mexico, and the Southwestern United States. The name "coatimundi" comes from the Tupian languages...
Biology and health sciences
Procyonidae
Animals
66284
https://en.wikipedia.org/wiki/Formic%20acid
Formic acid
Formic acid (), systematically named methanoic acid, is the simplest carboxylic acid, and has the chemical formula HCOOH and structure . It is an important intermediate in chemical synthesis and occurs naturally, most notably in some ants. Esters, salts and the anion derived from formic acid are called formates. Indust...
Physical sciences
Specific acids
Chemistry
66286
https://en.wikipedia.org/wiki/Organic%20acid
Organic acid
An organic acid is an organic compound with acidic properties. The most common organic acids are the carboxylic acids, whose acidity is associated with their carboxyl group –COOH. Sulfonic acids, containing the group –SO2OH, are relatively stronger acids. Alcohols, with –OH, can act as acids but they are usually very w...
Physical sciences
Specific acids
Chemistry
66306
https://en.wikipedia.org/wiki/Osmium%20tetroxide
Osmium tetroxide
Osmium tetroxide (also osmium(VIII) oxide) is the chemical compound with the formula OsO4. The compound is noteworthy for its many uses, despite its toxicity and the rarity of osmium. It also has a number of unusual properties, one being that the solid is volatile. The compound is colourless, but most samples appear y...
Physical sciences
Oxide salts
Chemistry
66313
https://en.wikipedia.org/wiki/Redox
Redox
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduct...
Physical sciences
Chemistry
null
66315
https://en.wikipedia.org/wiki/Solid-state%20chemistry
Solid-state chemistry
Solid-state chemistry, also sometimes referred as materials chemistry, is the study of the synthesis, structure, and properties of solid phase materials. It therefore has a strong overlap with solid-state physics, mineralogy, crystallography, ceramics, metallurgy, thermodynamics, materials science and electronics with ...
Physical sciences
Subdisciplines
Chemistry
66321
https://en.wikipedia.org/wiki/Group%206%20element
Group 6 element
|- ! colspan=2 style="text-align:left;" | ↓ Period |- ! 4 | |- ! 5 | |- ! 6 | |- ! 7 | |- | colspan="2"| Legend |} Group 6, numbered by IUPAC style, is a group of elements in the periodic table. Its members are chromium (Cr), molybdenum (Mo), tungsten (W), and seaborgium (Sg). These are all transition metals and...
Physical sciences
Group 6
Chemistry
66338
https://en.wikipedia.org/wiki/Holography
Holography
Holography is a technique that enables a wavefront to be recorded and later reconstructed. It is best known as a method of generating three-dimensional images, and has a wide range of other uses, including data storage, microscopy, and interferometry. In principle, it is possible to make a hologram for any type of wave...
Technology
Basics_9
null
66364
https://en.wikipedia.org/wiki/Moggy
Moggy
A moggy is any cat which has not been intentionally bred. Moggies lack a standard appearance unlike pedigree cats which have a standard. In contexts where cats need to be registered—such as in veterinary practices or shelters—they are called a 'domestic short-hair' or 'domestic long-hair' depending on coat length. Alth...
Biology and health sciences
Cats
Animals
66388
https://en.wikipedia.org/wiki/Bronchodilator
Bronchodilator
A bronchodilator or broncholytic (although the latter occasionally includes secretory inhibition as well) is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lungs. Bronchodilators may be originating naturally within the body, or they ma...
Biology and health sciences
Specific drugs
Health
66391
https://en.wikipedia.org/wiki/Stimulant
Stimulant
Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition, mood, and physical performance. Some stimulants occur naturally, while others...
Biology and health sciences
General concepts_2
Health
66392
https://en.wikipedia.org/wiki/Cardiopulmonary%20resuscitation
Cardiopulmonary resuscitation
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation, or mouth to mouth in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is ...
Biology and health sciences
Treatments
Health
66394
https://en.wikipedia.org/wiki/Island%20of%20stability
Island of stability
In nuclear physics, the island of stability is a predicted set of isotopes of superheavy elements that may have considerably longer half-lives than known isotopes of these elements. It is predicted to appear as an "island" in the chart of nuclides, separated from known stable and long-lived primordial radionuclides. It...
Physical sciences
Nuclear physics
Physics
66432
https://en.wikipedia.org/wiki/Progesterone
Progesterone
Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the major progestogen in the body. Progesterone has a variety of important function...
Biology and health sciences
Animal hormones
Biology
66488
https://en.wikipedia.org/wiki/Moscow%20Metro
Moscow Metro
The Moscow Metro is a metro system serving the Russian capital of Moscow as well as the neighbouring cities of Krasnogorsk, Reutov, Lyubertsy and Kotelniki in Moscow Oblast. Opened in 1935 with one line and 13 stations, it was the first underground railway system in the Soviet Union. , the Moscow Metro had 297 statio...
Technology
Russia
null
66512
https://en.wikipedia.org/wiki/Fern
Fern
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissues that conduct water and nutrients, and in having life cycles in which the br...
Biology and health sciences
Pteridophytes
null
66535
https://en.wikipedia.org/wiki/Alternation%20of%20generations
Alternation of generations
Alternation of generations (also known as metagenesis or heterogenesis) is the predominant type of life cycle in plants and algae. In plants both phases are multicellular: the haploid sexual phase – the gametophyte – alternates with a diploid asexual phase – the sporophyte. A mature sporophyte produces haploid spores ...
Biology and health sciences
Plant reproduction
null
66549
https://en.wikipedia.org/wiki/Prairie
Prairie
Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type. Temperate grassland regions include the Pampas o...
Physical sciences
Grasslands
null
66556
https://en.wikipedia.org/wiki/Broccoli
Broccoli
Broccoli (Brassica oleracea var. italica) is an edible green plant in the cabbage family (family Brassicaceae, genus Brassica) whose large flowering head, stalk and small associated leaves are eaten as a vegetable. Broccoli is classified in the Italica cultivar group of the species Brassica oleracea. Broccoli has large...
Biology and health sciences
Brassicales
null
66560
https://en.wikipedia.org/wiki/Bracken
Bracken
Bracken (Pteridium) is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells (eggs and sperm). Brackens are noted for their large, highly divided leaves. They are...
Biology and health sciences
Ferns
Plants
66572
https://en.wikipedia.org/wiki/ENIAC
ENIAC
ENIAC (; Electronic Numerical Integrator and Computer) was the first programmable, electronic, general-purpose digital computer, completed in 1945. Other computers had some of these features, but ENIAC was the first to have them all. It was Turing-complete and able to solve "a large class of numerical problems" throug...
Technology
Computer hardware
null
66575
https://en.wikipedia.org/wiki/Nutrient
Nutrient
A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures such as hair, scales, feathers,...
Biology and health sciences
Health and fitness: General
Health
66607
https://en.wikipedia.org/wiki/Vine
Vine
A vine (; ) is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas, or runners. The word vine can also refer to such stems or runners themselves, for instance, when used in wicker work. In parts of the world, including the British Isles, the term "vine" usually applies exclusively t...
Biology and health sciences
Plant anatomy and morphology: General
Biology
66633
https://en.wikipedia.org/wiki/Moth
Moth
Moths are a group of insects that includes all members of the order Lepidoptera that are not butterflies. They were previously classified as suborder Heterocera, but the group is paraphyletic with respect to butterflies (suborder Rhopalocera) and neither subordinate taxon is used in modern classifications. Moths make u...
Biology and health sciences
Lepidoptera
null
66668
https://en.wikipedia.org/wiki/Bullhead%20shark
Bullhead shark
The bullhead sharks are members of the genus Heterodontus, the only members of the family Heterodontidae and only living members of the order Heterodontiformes. All are relatively small, with the largest species reaching just in maximum length. They are bottom feeders in tropical and subtropical waters. The Heterodon...
Biology and health sciences
Sharks
Animals
66675
https://en.wikipedia.org/wiki/Light%20curve
Light curve
In astronomy, a light curve is a graph of the light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y-axis and with time on the x-axis. The light is usually in a particular frequency interval or band. Light curves can be periodic, as in the case of...
Physical sciences
Basics
Astronomy
66687
https://en.wikipedia.org/wiki/Quercus%20rubra
Quercus rubra
Quercus rubra, the northern red oak, is an oak tree in the red oak group (Quercus section Lobatae). It is a native of North America, in the eastern and central United States and southeast and south-central Canada. It has been introduced to small areas in Western Europe, where it can frequently be seen cultivated in gar...
Biology and health sciences
Fagales
Plants
66706
https://en.wikipedia.org/wiki/Fraxinus
Fraxinus
Fraxinus (), commonly called ash, is a genus of plants in the olive and lilac family, Oleaceae, and comprises 45–65 species of usually medium-to-large trees, most of which are deciduous trees, although some subtropical species are evergreen trees. The genus is widespread throughout much of Europe, Asia, and North Ameri...
Biology and health sciences
Lamiales
null
66723
https://en.wikipedia.org/wiki/Respiratory%20system
Respiratory system
The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the environment in which it liv...
Biology and health sciences
Respiratory system
null
66728
https://en.wikipedia.org/wiki/Trail
Trail
A trail, also known as a path or track, is an unpaved lane or a small paved road not intended for usage by motorized vehicles, usually passing through a natural area. In the United Kingdom and Ireland, a path or footpath is the preferred term for a pedestrian or hiking trail. The term is also applied in North America t...
Technology
Road transport
null
66781
https://en.wikipedia.org/wiki/Oberon%20%28moon%29
Oberon (moon)
Oberon , also designated , is the outermost and second-largest major moon of the planet Uranus. It is the second-most massive of the Uranian moons, and the tenth-largest moon in the Solar System. Discovered by William Herschel in 1787, Oberon is named after the mythical king of the fairies who appears as a character in...
Physical sciences
Solar System
Astronomy
66797
https://en.wikipedia.org/wiki/Fibroblast
Fibroblast
A fibroblast is a type of biological cell typically with a spindle shape that synthesizes the extracellular matrix and collagen, produces the structural framework (stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals. Structure ...
Biology and health sciences
Tissues
Biology
66811
https://en.wikipedia.org/wiki/Seasonal%20affective%20disorder
Seasonal affective disorder
Seasonal affective disorder (SAD) is a mood disorder subset in which people who typically have normal mental health throughout most of the year exhibit depressive symptoms at the same time each year. It is commonly, but not always, associated with the reductions or increases in total daily sunlight hours that occur dur...
Biology and health sciences
Mental disorders
Health
66926
https://en.wikipedia.org/wiki/Demodulation
Demodulation
Demodulation is the process of extracting the original information-bearing signal from a carrier wave. A demodulator is an electronic circuit (or computer program in a software-defined radio) that is used to recover the information content from the modulated carrier wave. There are many types of modulation, and there ...
Technology
Telecommunications
null
66962
https://en.wikipedia.org/wiki/Typha
Typha
Typha is a genus of about 30 species of monocotyledonous flowering plants in the family Typhaceae. These plants have a variety of common names, in British English as bulrush or (mainly historically) reedmace, in American English as cattail, or punks, in Australia as cumbungi or bulrush, in Canada as bulrush or cattail...
Biology and health sciences
Poales
null
66966
https://en.wikipedia.org/wiki/Vascular%20plant
Vascular plant
Vascular plants (), also called tracheophytes (, ) or collectively tracheophyta (; ), are plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. The group includes most l...
Biology and health sciences
Vascular plants (except seed plants)
Plants
66973
https://en.wikipedia.org/wiki/Lycopodiopsida
Lycopodiopsida
Lycopodiopsida is a class of vascular plants also known as lycopsids, lycopods, or lycophytes. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching stems bearing simple leaves called microphylls and reproduce by means of spores borne in sporangia on t...
Biology and health sciences
Lycophytes
Plants
66981
https://en.wikipedia.org/wiki/Epidemic
Epidemic
An epidemic (from Greek ἐπί epi "upon or above" and δῆμος demos "people") is the rapid spread of disease to a large number of hosts in a given population within a short period of time. For example, in meningococcal infections, an attack rate in excess of 15 cases per 100,000 people for two consecutive weeks is consider...
Biology and health sciences
Concepts
Health
66986
https://en.wikipedia.org/wiki/Woodland
Woodland
A woodland () is, in the broad sense, land covered with woody plants (trees and shrubs), or in a narrow sense, synonymous with wood (or in the U.S., the plurale tantum woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see differences between British, American and Australian E...
Physical sciences
Forests
Earth science
66997
https://en.wikipedia.org/wiki/Epidemiology
Epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and determinants of health and disease conditions in a defined population, and application of this knowledge to prevent diseases. It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by ...
Biology and health sciences
Fields of medicine
null
67049
https://en.wikipedia.org/wiki/Selaginella
Selaginella
Selaginella, also known as spikemosses or lesser clubmosses is a genus of lycophyte. It is usually treated as the only genus in the family Selaginellaceae, with over 750 known species. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having spores of two t...
Biology and health sciences
Lycophytes
Plants
67058
https://en.wikipedia.org/wiki/Abdominal%20cavity
Abdominal cavity
The abdominal cavity is a large body cavity in humans and many other animals that contain organs. It is a part of the abdominopelvic cavity. It is located below the thoracic cavity, and above the pelvic cavity. Its dome-shaped roof is the thoracic diaphragm, a thin sheet of muscle under the lungs, and its floor is the ...
Biology and health sciences
External anatomy and regions of the body
Biology
67060
https://en.wikipedia.org/wiki/Hot%20spring
Hot spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circulation through faults to hot rock deep in the Earth's crust. Hot spring wa...
Physical sciences
Volcanology
Earth science
67075
https://en.wikipedia.org/wiki/Isoetes
Isoetes
Isoetes, commonly known as the quillworts, is a genus of lycopod. It is the only living genus in the family Isoetaceae and order Isoetales. , there were about 200 recognized species, with a cosmopolitan distribution mostly in aquatic habitats but with the individual species often scarce to rare. Species virtually ident...
Biology and health sciences
Lycophytes
Plants
67077
https://en.wikipedia.org/wiki/Equisetum
Equisetum
Equisetum (; horsetail) is the only living genus in Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. Equisetum is a "living fossil", the only living genus of the entire subclass Equisetidae, which for over 100 million years was much more diverse and dominated the understorey of lat...
Biology and health sciences
Pteridophytes
null
67088
https://en.wikipedia.org/wiki/Conservation%20of%20energy
Conservation of energy
The law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. In the case of a closed system, the principle says that the total amount of energy within the system can only be changed through energy entering or leaving the system. Energy can ...
Physical sciences
Basics_6
null
67158
https://en.wikipedia.org/wiki/Red%20blood%20cell
Red blood cell
Red blood cells (RBCs), referred to as erythrocytes (, with -cyte translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen () to the body tiss...
Biology and health sciences
Circulatory system
null
67159
https://en.wikipedia.org/wiki/Blood%20cell
Blood cell
A blood cell (also called a hematopoietic cell, hemocyte, or hematocyte) is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Together, these three kinds of blood cells add...
Biology and health sciences
Circulatory system
Biology
67166
https://en.wikipedia.org/wiki/Placenta
Placenta
The placenta (: placentas or placentae) is a temporary embryonic and later fetal organ that begins developing from the blastocyst shortly after implantation. It plays critical roles in facilitating nutrient, gas and waste exchange between the physically separate maternal and fetal circulations, and is an important endo...
Biology and health sciences
Reproductive system
null
67193
https://en.wikipedia.org/wiki/Testicle
Testicle
A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of androgens, primarily testosterone. The release of testosterone is regulated by luteinizing hormone (LH) from the anter...
Biology and health sciences
Reproductive system
null
67211
https://en.wikipedia.org/wiki/Electron%20configuration
Electron configuration
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. For example, the electron configuration of the neon atom is , meaning that the 1s, 2s, and 2p subshells are occupied by two, two, and...
Physical sciences
Atomic physics
null
67231
https://en.wikipedia.org/wiki/Metre%20per%20second
Metre per second
The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in a time of one second. According to the definition of metre, is exactly of ...
Physical sciences
Speed
Basics and measurement
67244
https://en.wikipedia.org/wiki/Ecological%20niche
Ecological niche
In ecology, a niche is the match of a species to a specific environmental condition. It describes how an organism or population responds to the distribution of resources and competitors (for example, by growing when resources are abundant, and when predators, parasites and pathogens are scarce) and how it in turn alter...
Biology and health sciences
Ecology
null
67252
https://en.wikipedia.org/wiki/Birch
Birch
A birch is a thin-leaved deciduous hardwood tree of the genus Betula (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech-oak family Fagaceae. The genus Betula contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Red List of Threatened Species. The...
Biology and health sciences
Fagales
null
67401
https://en.wikipedia.org/wiki/Grapefruit
Grapefruit
The grapefruit (Citrus × paradisi) is a subtropical citrus tree known for its relatively large, sour to semi-sweet, somewhat bitter fruit. The flesh of the fruit is segmented and varies in color from pale yellow to dark red. Grapefruits originated in Barbados in the 18th century. They are a citrus hybrid that was crea...
Biology and health sciences
Sapindales
null
67405
https://en.wikipedia.org/wiki/Great%20Red%20Spot
Great Red Spot
The Great Red Spot is a persistent high-pressure region in the atmosphere of Jupiter, producing an anticyclonic storm that is the largest in the Solar System. It is the most recognizable feature on Jupiter, owing to its red-orange color whose origin is still unknown. Located 22 degrees south of Jupiter's equator, it pr...
Physical sciences
Solar System
Astronomy
67409
https://en.wikipedia.org/wiki/Boeing%20707
Boeing 707
The Boeing 707 is an early American long-range narrow-body airliner, the first jetliner developed and produced by Boeing Commercial Airplanes. Developed from the Boeing 367-80 prototype first flown in 1954, the initial first flew on December 20, 1957. Pan Am began regular 707 service on October 26, 1958. With versio...
Technology
Specific aircraft_2
null
67430
https://en.wikipedia.org/wiki/Nymphaeaceae
Nymphaeaceae
Nymphaeaceae () is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate and tropical climates around the world. The family contains five genera with about 70 known species. Water lilies are rooted in soil in bodies of water, with leaves and flowers floating on ...
Biology and health sciences
Nymphaeales
Plants
67491
https://en.wikipedia.org/wiki/Unbinilium
Unbinilium
Unbinilium, also known as eka-radium or element 120, is a hypothetical chemical element; it has symbol Ubn and atomic number 120. Unbinilium and Ubn are the temporary systematic IUPAC name and symbol, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the periodic table ...
Physical sciences
Periods
Chemistry
67492
https://en.wikipedia.org/wiki/Ununennium
Ununennium
Ununennium, also known as eka-francium or element 119, is a hypothetical chemical element; it has symbol Uue and atomic number 119. Ununennium and Uue are the temporary systematic IUPAC name and symbol respectively, which are used until the element has been discovered, confirmed, and a permanent name is decided upon. I...
Physical sciences
Periods
Chemistry
67513
https://en.wikipedia.org/wiki/Systematic%20element%20name
Systematic element name
A systematic element name is the temporary name assigned to an unknown or recently synthesized chemical element. A systematic symbol is also derived from this name. In chemistry, a transuranic element receives a permanent name and symbol only after its synthesis has been confirmed. In some cases, such as the Transfer...
Physical sciences
Nomenclature
Chemistry
67514
https://en.wikipedia.org/wiki/Moscovium
Moscovium
Moscovium is a synthetic chemical element; it has symbol Mc and atomic number 115. It was first synthesized in 2003 by a joint team of Russian and American scientists at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. In December 2015, it was recognized as one of four new elements by the Joint Working...
Physical sciences
Group 15
Chemistry
67554
https://en.wikipedia.org/wiki/Invasive%20species
Invasive species
An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its f...
Biology and health sciences
Ecology
null
67611
https://en.wikipedia.org/wiki/Tennessine
Tennessine
Tennessine is a synthetic chemical element; it has symbol Ts and atomic number 117. It has the second-highest atomic number and joint-highest atomic mass of all known elements and is the penultimate element of the 7th period of the periodic table. It is named after the U.S. state of Tennessee, where key research instit...
Physical sciences
Group 17
Chemistry
67619
https://en.wikipedia.org/wiki/Elm
Elm
Elms are deciduous and semi-deciduous trees comprising the genus Ulmus in the family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of North America and Eurasia, presently ranging southward in the Middle East to Lebanon and Israel, and across t...
Biology and health sciences
Rosales
null
1070326
https://en.wikipedia.org/wiki/Total%20derivative
Total derivative
In mathematics, the total derivative of a function at a point is the best linear approximation near this point of the function with respect to its arguments. Unlike partial derivatives, the total derivative approximates the function with respect to all of its arguments, not just a single one. In many situations, thi...
Mathematics
Multivariable and vector calculus
null
1071613
https://en.wikipedia.org/wiki/Papaver%20somniferum
Papaver somniferum
Papaver somniferum, commonly known as the opium poppy or breadseed poppy, is a species of flowering plant in the family Papaveraceae. It is the species of plant from which both opium and poppy seeds are derived and is also a valuable ornamental plant grown in gardens. Its native range was east of the Mediterranean Sea,...
Biology and health sciences
Ranunculales
Plants
1072236
https://en.wikipedia.org/wiki/Unit%20operation
Unit operation
In chemical engineering and related fields, a unit operation is a basic step in a process. Unit operations involve a physical change or chemical transformation such as separation, crystallization, evaporation, filtration, polymerization, isomerization, and other reactions. For example, in milk processing, the following...
Physical sciences
Chemical engineering
Chemistry
1072751
https://en.wikipedia.org/wiki/Habitable%20zone
Habitable zone
In astronomy and astrobiology, the habitable zone (HZ), or more precisely the circumstellar habitable zone (CHZ), is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure. The bounds of the HZ are based on Earth's position in the Solar System a...
Physical sciences
Planetary science
Astronomy
1072889
https://en.wikipedia.org/wiki/Superacid
Superacid
In chemistry, a superacid (according to the original definition) is an acid with an acidity greater than that of 100% pure sulfuric acid (), which has a Hammett acidity function (H0) of −12. According to the modern definition, a superacid is a medium in which the chemical potential of the proton is higher than in pure ...
Physical sciences
Specific acids
Chemistry
1073054
https://en.wikipedia.org/wiki/Punji%20stick
Punji stick
The punji stick or punji stake is a type of booby trapped stake. It is a simple spike, made out of wood or bamboo, which is sharpened, heated, and usually set in a hole. Punji sticks are usually deployed in substantial numbers. The Oxford English Dictionary (third edition, 2007) lists less frequent, earlier spellings f...
Technology
Military technology: General
null
1074025
https://en.wikipedia.org/wiki/Ethiopian%20wolf
Ethiopian wolf
The Ethiopian wolf (Canis simensis), also called the red jackal, the Simien jackal or Simien fox, is a canine native to the Ethiopian Highlands. In southeastern Ethiopia, it is also known as the horse jackal. It is similar to the coyote in size and build, and is distinguished by its long and narrow skull, and its red a...
Biology and health sciences
Canines
Animals
14835582
https://en.wikipedia.org/wiki/Algebraic%20combinatorics
Algebraic combinatorics
Algebraic combinatorics is an area of mathematics that employs methods of abstract algebra, notably group theory and representation theory, in various combinatorial contexts and, conversely, applies combinatorial techniques to problems in algebra. History The term "algebraic combinatorics" was introduced in the late 1...
Mathematics
Combinatorics
null
11174927
https://en.wikipedia.org/wiki/Beaver%20dam
Beaver dam
A beaver dam or beaver impoundment is a dam built by beavers; it creates a pond which protects against predators such as coyotes, wolves and bears, and holds their food during winter. These structures modify the natural environment in such a way that the overall ecosystem builds upon the change, making beavers a keysto...
Biology and health sciences
Shelters and structures
Animals
13728473
https://en.wikipedia.org/wiki/Tropical%20savanna%20climate
Tropical savanna climate
Tropical savanna climate or tropical wet and dry climate is a tropical climate sub-type that corresponds to the Köppen climate classification categories Aw (for a dry "winter") and As (for a dry "summer"). The driest month has less than of precipitation and also less than mm of precipitation. This latter fact is in a...
Physical sciences
Climates
Earth science
4308142
https://en.wikipedia.org/wiki/Guan%20%28bird%29
Guan (bird)
The guans are a number of bird genera which make up the largest group in the family Cracidae. They are found mainly in northern South America, southern Central America, and a few adjacent Caribbean islands. There is also the peculiar horned guan (Oreophasis derbianus) which is not a true guan, but a very distinct and ...
Biology and health sciences
Galliformes
Animals
9701472
https://en.wikipedia.org/wiki/Timema
Timema
Timema is a genus of relatively short-bodied, stout and wingless stick insects native to the far western United States, and the sole extant member of the family Timematidae. The genus was first described in 1895 by Samuel Hubbard Scudder, based on observations of the species Timema californicum. Compared to other st...
Biology and health sciences
Insects: General
Animals
3166203
https://en.wikipedia.org/wiki/Luminosity%20distance
Luminosity distance
Luminosity distance DL is defined in terms of the relationship between the absolute magnitude M and apparent magnitude m of an astronomical object. which gives: where DL is measured in parsecs. For nearby objects (say, in the Milky Way) the luminosity distance gives a good approximation to the natural notion of dista...
Physical sciences
Basics
Astronomy
3167641
https://en.wikipedia.org/wiki/Ammonium%20acetate
Ammonium acetate
Ammonium acetate, also known as spirit of Mindererus in aqueous solution, is a chemical compound with the formula NH4CH3CO2. It is a white, hygroscopic solid and can be derived from the reaction of ammonia and acetic acid. It is available commercially. History The synonym Spirit of Mindererus is named after R. Mindere...
Physical sciences
Acetates
Chemistry
3168368
https://en.wikipedia.org/wiki/Cygnus%20Loop
Cygnus Loop
The Cygnus Loop (radio source W78, or Sharpless 103) is a large supernova remnant (SNR) in the constellation Cygnus, an emission nebula measuring nearly 3° across. Some arcs of the loop, known collectively as the Veil Nebula or Cirrus Nebula, emit in the visible electromagnetic range. Radio, infrared, and X-ray images ...
Physical sciences
Notable nebulae
Astronomy
3172179
https://en.wikipedia.org/wiki/Medical%20specialty
Medical specialty
A medical specialty is a branch of medical practice that is focused on a defined group of patients, diseases, skills, or philosophy. Examples include those branches of medicine that deal exclusively with children (pediatrics), cancer (oncology), laboratory medicine (pathology), or primary care (family medicine). After ...
Biology and health sciences
Fields of medicine
Health