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Neurosis (: neuroses) is a term mainly used today by followers of Freudian thinking to describe mental disorders caused by past anxiety, often that has been repressed. In recent history, the term has been used to refer to anxiety-related conditions more generally.
The term "neurosis" is no longer used in condition nam... | Neurosis | Wikipedia | 484 | 47588 | https://en.wikipedia.org/wiki/Neurosis | Biology and health sciences | Mental disorder | null | vital_articles |
Morphine was first isolated from opium in 1805, by German chemist Friedrich Sertürner. After the publication of his third paper on the topic in 1817, morphine became more widely known, and used to treat neuroses and other kinds of mental distress. After becoming addicted to this highly addictive substance, he warned "I... | Neurosis | Wikipedia | 479 | 47588 | https://en.wikipedia.org/wiki/Neurosis | Biology and health sciences | Mental disorder | null | vital_articles |
According to Breuer, the slow and laborious progress of her "remembering work" in which she recalled individual symptoms after they had occurred, thus "dissolving" them, came to a conclusion on 7 June 1882 after she had reconstructed the first night of hallucinations in Ischl. "She has fully recovered since that time" ... | Neurosis | Wikipedia | 472 | 47588 | https://en.wikipedia.org/wiki/Neurosis | Biology and health sciences | Mental disorder | null | vital_articles |
Austrian psychiatrist Sigmund Freud was a student of Charcot in 1885–6. In 1893 Freud credited Charcot with being the source of "all the modern advances made in the understanding and knowledge of hysteria."
French psychiatrist Pierre Janet released his book L'automatisme psychologique (Psychological automatism) in 188... | Neurosis | Wikipedia | 498 | 47588 | https://en.wikipedia.org/wiki/Neurosis | Biology and health sciences | Mental disorder | null | vital_articles |
Our experiences have shown us, however, that the most various symptoms, which are ostensibly spontaneous and, as one might say, idiopathic products of hysteria, are just as strictly related to the precipitating trauma as the phenomena to which we have just alluded and which exhibit the connection quite clearly.This pap... | Neurosis | Wikipedia | 491 | 47588 | https://en.wikipedia.org/wiki/Neurosis | Biology and health sciences | Mental disorder | null | vital_articles |
Janet founded the French "Société de psychologie" in 1901. This later became the "Société française de psychologie", and continues today as France's main psychology body.
Barbiturates are a class of highly addictive sedative drugs. The first barbiturate, barbital, was synthesized in 1902 by German chemists Emil Fische... | Neurosis | Wikipedia | 427 | 47588 | https://en.wikipedia.org/wiki/Neurosis | Biology and health sciences | Mental disorder | null | vital_articles |
Progressive muscle relaxation (PMR) was first developed by American psychiatrist and physiologist Edmund Jacobson. This began at Harvard University in 1908. PMR involves learning to relieve the tension in specific muscle groups by first tensing and then relaxing each muscle group. When the muscle tension is released, a... | Neurosis | Wikipedia | 119 | 47588 | https://en.wikipedia.org/wiki/Neurosis | Biology and health sciences | Mental disorder | null | vital_articles |
In electronics, acoustics, and related fields, the waveform of a signal is the shape of its graph as a function of time, independent of its time and magnitude scales and of any displacement in time. Periodic waveforms repeat regularly at a constant period. The term can also be used for non-periodic or aperiodic signals... | Waveform | Wikipedia | 491 | 47592 | https://en.wikipedia.org/wiki/Waveform | Physical sciences | Waves | Physics | vital_articles |
Other periodic waveforms are often called composite waveforms and can often be described as a combination of a number of sinusoidal waves or other basis functions added together. | Waveform | Wikipedia | 33 | 47592 | https://en.wikipedia.org/wiki/Waveform | Physical sciences | Waves | Physics | vital_articles |
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical suspenders, have a long history in many mountainous parts of the world.
Beside... | Suspension bridge | Wikipedia | 338 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
The Tibetan siddha and bridge-builder Thangtong Gyalpo originated the use of iron chains in his version of simple suspension bridges. In 1433, Gyalpo built eight bridges in eastern Bhutan. The last surviving chain-linked bridge of Gyalpo's was the Thangtong Gyalpo Bridge in Duksum en route to Trashi Yangtse, which was ... | Suspension bridge | Wikipedia | 310 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
Early British chain bridges included the Dryburgh Abbey Bridge (1817) and 137 m Union Bridge (1820), with spans rapidly increasing to 176 m with the Menai Bridge (1826), "the first important modern suspension bridge". The first chain bridge on the German speaking territories was the Chain Bridge in Nuremberg. The Sagar... | Suspension bridge | Wikipedia | 499 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
In the United States, the first major wire-cable suspension bridge was the Wire Bridge at Fairmount in Philadelphia, Pennsylvania. Designed by Charles Ellet Jr. and completed in 1842, it had a span of 109 m. Ellet's Niagara Falls suspension bridge (1847–48) was abandoned before completion. It was used as scaffolding fo... | Suspension bridge | Wikipedia | 430 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
In cable-stayed bridges, the towers are the primary load-bearing structures that transmit the bridge loads to the ground. A cantilever approach is often used to support the bridge deck near the towers, but lengths further from them are supported by cables running directly to the towers. By design, all static horizontal... | Suspension bridge | Wikipedia | 464 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
The main suspension cables in older bridges were often made from a chain or linked bars, but modern bridge cables are made from multiple strands of wire. This not only adds strength but improves reliability (often called redundancy in engineering terms) because the failure of a few flawed strands in the hundreds used p... | Suspension bridge | Wikipedia | 392 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
Forces
Three kinds of forces operate on any bridge: the dead load, the live load, and the dynamic load. Dead load refers to the weight of the bridge itself. Like any other structure, a bridge has a tendency to collapse simply because of the gravitational forces acting on the materials of which the bridge is made. Live... | Suspension bridge | Wikipedia | 307 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
Typical suspension bridges are constructed using a sequence generally described as follows. Depending on length and size, construction may take anywhere between a year and a half (construction on the original Tacoma Narrows Bridge took only 19 months) up to as long as a decade (the Akashi-Kaikyō Bridge's construction b... | Suspension bridge | Wikipedia | 489 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
Gantries are placed upon the catwalks, which will support the main cable spinning reels. Then, cables attached to winches are installed, and in turn, the main cable spinning devices are installed.
High strength wire (typically 4 or 6 gauge galvanized steel wire), is pulled in a loop by pulleys on the traveler, with one... | Suspension bridge | Wikipedia | 358 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
Special lifting hoists attached to the suspenders or from the main cables are used to lift prefabricated sections of the bridge deck to the proper level, provided that the local conditions allow the sections to be carried below the bridge by barge or other means. Otherwise, a traveling cantilever derrick may be used t... | Suspension bridge | Wikipedia | 220 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
Longest spans
Suspension bridges are typically ranked by the length of their main span. These are the ten bridges with the longest spans, followed by the length of the span and the year the bridge opened for traffic:
Other examples
(Chronological)
Union Bridge (England/Scotland, 1820), the longest span (137 m) fr... | Suspension bridge | Wikipedia | 449 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
Broughton Suspension Bridge (England) was an iron chain bridge built in 1826. One of Europe's first suspension bridges, it collapsed in 1831 due to mechanical resonance induced by troops marching in step. As a result of the incident, the British Army issued an order that troops should "break step" when crossing a bridg... | Suspension bridge | Wikipedia | 499 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
On 30 October 2022, Jhulto Pul, a pedestrian suspension bridge over the Machchhu River in the city of Morbi, Gujarat, India collapsed, leading to the deaths of at least 141 people. | Suspension bridge | Wikipedia | 44 | 47607 | https://en.wikipedia.org/wiki/Suspension%20bridge | Technology | Transport infrastructure | null | vital_articles |
The Great Belt Bridge () or Great Belt fixed link () is a multi-element fixed link crossing the Great Belt strait between the Danish islands of Zealand and Funen. It consists of a road suspension bridge and a railway tunnel between Zealand and the small island Sprogø in the middle of the Great Belt, and a box-girder br... | Great Belt Bridge | Wikipedia | 494 | 47610 | https://en.wikipedia.org/wiki/Great%20Belt%20Bridge | Technology | Bridges | null | vital_articles |
Construction drafts for a fixed link were presented as early as the 1850s, with several suggestions appearing in the following decades. The Danish State Railways, responsible for the ferry service, presented plans for a bridge in 1934. The concepts of bridges over Øresund (152 million DKK) and Storebælt (257 million DK... | Great Belt Bridge | Wikipedia | 505 | 47610 | https://en.wikipedia.org/wiki/Great%20Belt%20Bridge | Technology | Bridges | null | vital_articles |
East Bridge
Built between 1991 and 1998 at a cost of US$950 million, the East Bridge (Østbroen) is a suspension bridge between Halsskov and Sprogø. It is long with a free span of ,. The East Bridge had been planned to be completed in time to be the longest bridge in the world, but there were delays in construction. T... | Great Belt Bridge | Wikipedia | 480 | 47610 | https://en.wikipedia.org/wiki/Great%20Belt%20Bridge | Technology | Bridges | null | vital_articles |
There were delays and cost overruns in the tunnel construction. The plan was to open it in 1993, giving the trains a head start of three years over road traffic, but train traffic started in 1997 and road traffic in 1998. During construction the sea bed gave way and one of the tunnels was flooded. The water continued t... | Great Belt Bridge | Wikipedia | 454 | 47610 | https://en.wikipedia.org/wiki/Great%20Belt%20Bridge | Technology | Bridges | null | vital_articles |
By train the time savings are significant as well. The journey has been reduced by 60 minutes, and there are many more seats available because more carriages may be added to a train that does not have to fit on a ferry. The seating capacity offered by DSB across the Great Belt on an ordinary Wednesday has risen from 11... | Great Belt Bridge | Wikipedia | 452 | 47610 | https://en.wikipedia.org/wiki/Great%20Belt%20Bridge | Technology | Bridges | null | vital_articles |
Environmental considerations have been an integral part of the project, and have been of decisive significance for the choice of alignment and determination of the design. Great Belt A/S established an environmental monitoring programme in 1988, and initiated co-operation with authorities and external consultants on th... | Great Belt Bridge | Wikipedia | 470 | 47610 | https://en.wikipedia.org/wiki/Great%20Belt%20Bridge | Technology | Bridges | null | vital_articles |
The West Bridge has been struck by sea traffic twice. While the link was still under construction on 14 September 1993, the ferry M/F Romsø drifted off course in bad weather and hit the West Bridge. At 19:17 on 3 March 2005, the 3,500-ton freighter MV Karen Danielsen crashed into the West Bridge 800 metres from Funen. ... | Great Belt Bridge | Wikipedia | 375 | 47610 | https://en.wikipedia.org/wiki/Great%20Belt%20Bridge | Technology | Bridges | null | vital_articles |
Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma. Some ex... | Hexactinellid | Wikipedia | 459 | 47612 | https://en.wikipedia.org/wiki/Hexactinellid | Biology and health sciences | Porifera | Animals | vital_articles |
All hexactinellids have the potential to grow to different sizes, but the average maximum growth is estimated to be around 32 centimeters long. Some grow past that length and continue to extend their length up to 1 meter long. The estimated life expectancy for hexactinellids that grow around 1 meter is approximately 20... | Hexactinellid | Wikipedia | 480 | 47612 | https://en.wikipedia.org/wiki/Hexactinellid | Biology and health sciences | Porifera | Animals | vital_articles |
Some types of cells have a single nucleus and membrane each but are connected to other single-nucleus cells and to the main syncytium by "bridges" made of cytoplasm. The sclerocytes that build spicules have multiple nuclei, and in glass sponge larvae they are connected to other tissues by cytoplasm bridges; such connec... | Hexactinellid | Wikipedia | 399 | 47612 | https://en.wikipedia.org/wiki/Hexactinellid | Biology and health sciences | Porifera | Animals | vital_articles |
Reefs
The sponges form reefs (called sponge reefs) off the coast of British Columbia, southeast Alaska and Washington state, which are studied in the Sponge Reef Project. In the case of Sarostegia oculata, this species almost always hosts symbiotic zoanthids, which cause the hexactinellid sponge to imitate the appearan... | Hexactinellid | Wikipedia | 448 | 47612 | https://en.wikipedia.org/wiki/Hexactinellid | Biology and health sciences | Porifera | Animals | vital_articles |
Evolution and taxonomy
The earliest known hexactinellids are from the earliest Cambrian or late Neoproterozoic eras; Helicolocellus is a possible hexactinellid relative from the late Ediacaran. They are fairly common relative to demosponges as fossils, but this is thought to be, at least in part, because their spicules... | Hexactinellid | Wikipedia | 226 | 47612 | https://en.wikipedia.org/wiki/Hexactinellid | Biology and health sciences | Porifera | Animals | vital_articles |
A bomb is an explosive weapon that uses the exothermic reaction of an explosive material to provide an extremely sudden and violent release of energy. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanical stress, the impact and penetration of pressure-driven projectiles, pressure ... | Bomb | Wikipedia | 494 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
The History of Jin (金史) (compiled by 1345) states that in 1232, as the Mongol general Subutai (1176–1248) descended on the Jin stronghold of Kaifeng, the defenders had a "thunder crash bomb" which "consisted of gunpowder put into an iron container ... then when the fuse was lit (and the projectile shot off) there was a... | Bomb | Wikipedia | 424 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
Heat
A thermal wave is created by the sudden release of heat caused by an explosion. Military bomb tests have documented temperatures of up to 2,480 °C (4,500 °F). While capable of inflicting severe to catastrophic burns and causing secondary fires, thermal wave effects are considered very limited in range compared to ... | Bomb | Wikipedia | 266 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
Effects on living things
To people who are close to a blast incident, such as bomb disposal technicians, soldiers wearing body armor, deminers, or individuals wearing little to no protection, there are four types of blast effects on the human body: overpressure (shock), fragmentation, impact, and heat. Overpressure re... | Bomb | Wikipedia | 400 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
Improvised explosive materials are typically unstable and subject to spontaneous, unintentional detonation triggered by a wide range of environmental effects, ranging from impact and friction to electrostatic shock. Even subtle motion, change in temperature, or the nearby use of cellphones or radios can trigger an unst... | Bomb | Wikipedia | 417 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
Compressed gas
Relatively small explosions can be produced by pressurizing a container until catastrophic failure such as with a dry ice bomb. Technically, devices that create explosions of this type can not be classified as "bombs" by the definition presented at the top of this article. However, the explosions created... | Bomb | Wikipedia | 465 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
Nuclear fission
Nuclear fission type atomic bombs utilize the energy present in very heavy atomic nuclei, such as U-235 or Pu-239. In order to release this energy rapidly, a certain amount of the fissile material must be very rapidly consolidated while being exposed to a neutron source. If consolidation occurs slowly, ... | Bomb | Wikipedia | 317 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
Other
Aerial bomb – designed to be dropped from a military aircraft (or even any aircraft) and carried on hardpoints or in bomb bays
Delay-action bomb – explodes some time after impact, as opposed to before or on impact
Dummy bomb – harmless bomb that has been fully disabled or has had its explosive contents removed... | Bomb | Wikipedia | 371 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
During World War II bombing became a major military feature, and a number of novel delivery methods were introduced. These included Barnes Wallis's bouncing bomb, designed to bounce across water, avoiding torpedo nets and other underwater defenses, until it reached a dam, ship, or other destination, where it would sink... | Bomb | Wikipedia | 464 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
A bomb destroying a rail track just before a train arrives will usually cause the train to derail. In addition to the damage to vehicles and people, a bomb exploding in a transport network often damages, and is sometimes mainly intended to damage, the network itself. This applies to railways, bridges, runways, and port... | Bomb | Wikipedia | 307 | 47628 | https://en.wikipedia.org/wiki/Bomb | Technology | Weapons | null | vital_articles |
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetic, weak and strong interactions – excluding gravity) in the universe and classifying all known elementary particles. It was developed in stages throughout the latter half of the 20th century, throug... | Standard Model | Wikipedia | 491 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
In 1961, Sheldon Glashow combined the electromagnetic and weak interactions. In 1964, Murray Gell-Mann and George Zweig introduced quarks and that same year Oscar W. Greenberg implicitly introduced color charge of quarks. In 1967 Steven Weinberg and Abdus Salam incorporated the Higgs mechanism into Glashow's electrowea... | Standard Model | Wikipedia | 505 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
The Standard Model includes 12 elementary particles of spin , known as fermions. Fermions respect the Pauli exclusion principle, meaning that two identical fermions cannot simultaneously occupy the same quantum state in the same atom. Each fermion has a corresponding antiparticle, which are particles that have correspo... | Standard Model | Wikipedia | 261 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
There are six quarks: up, down, charm, strange, top, and bottom. Quarks carry color charge, and hence interact via the strong interaction. The color confinement phenomenon results in quarks being strongly bound together such that they form color-neutral composite particles called hadrons; quarks cannot individually exi... | Standard Model | Wikipedia | 256 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
The Standard Model includes 4 kinds of gauge bosons of spin 1, with bosons being quantum particles containing an integer spin. The gauge bosons are defined as force carriers, as they are responsible for mediating the fundamental interactions. The Standard Model explains the four fundamental forces as arising from the i... | Standard Model | Wikipedia | 480 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
The Feynman diagram calculations, which are a graphical representation of the perturbation theory approximation, invoke "force mediating particles", and when applied to analyze high-energy scattering experiments are in reasonable agreement with the data. However, perturbation theory (and with it the concept of a "force... | Standard Model | Wikipedia | 118 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
Higgs boson
The Higgs particle is a massive scalar elementary particle theorized by Peter Higgs (and others) in 1964, when he showed that Goldstone's 1962 theorem (generic continuous symmetry, which is spontaneously broken) provides a third polarisation of a massive vector field. Hence, Goldstone's original scalar do... | Standard Model | Wikipedia | 505 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
Technically, quantum field theory provides the mathematical framework for the Standard Model, in which a Lagrangian controls the dynamics and kinematics of the theory. Each kind of particle is described in terms of a dynamical field that pervades space-time.
The construction of the Standard Model proceeds following the... | Standard Model | Wikipedia | 500 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
The QCD Lagrangian is invariant under local SU(3) gauge transformations; i.e., transformations of the form , where is 3 × 3 unitary matrix with determinant 1, making it a member of the group SU(3), and is an arbitrary function of spacetime.
Electroweak sector
The electroweak sector is a Yang–Mills gauge theory wit... | Standard Model | Wikipedia | 498 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
where , so that acquires a non-zero Vacuum expectation value, which generates masses for the Electroweak gauge fields (the Higgs mechanism), and , so that the potential is bounded from below. The quartic term describes self-interactions of the scalar field .
The minimum of the potential is degenerate with an infinite... | Standard Model | Wikipedia | 511 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
Electromagnetism
Electromagnetism is the only long-range force in the Standard Model. It is mediated by photons and couples to electric charge. Electromagnetism is responsible for a wide range of phenomena including atomic electron shell structure, chemical bonds, electric circuits and electronics. Electromagnetic in... | Standard Model | Wikipedia | 420 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
While quarks are bound in hadrons by the fundamental strong interaction, which is mediated by gluons, nucleons are bound by an emergent phenomenon termed the residual strong force or nuclear force. This interaction is mediated by mesons, such as the pion. The color charges inside the nucleon cancel out, meaning most of... | Standard Model | Wikipedia | 495 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
Theoretical and experimental research has attempted to extend the Standard Model into a unified field theory or a theory of everything, a complete theory explaining all physical phenomena including constants. Inadequacies of the Standard Model that motivate such research include:
The model does not explain gravitation... | Standard Model | Wikipedia | 483 | 47641 | https://en.wikipedia.org/wiki/Standard%20Model | Physical sciences | Physics | null | vital_articles |
Reproducibility, closely related to replicability and repeatability, is a major principle underpinning the scientific method. For the findings of a study to be reproducible means that results obtained by an experiment or an observational study or in a statistical analysis of a data set should be achieved again with a h... | Reproducibility | Wikipedia | 386 | 47651 | https://en.wikipedia.org/wiki/Reproducibility | Physical sciences | Science basics | Basics and measurement | vital_articles |
The air pump, which in the 17th century was a complicated and expensive apparatus to build, also led to one of the first documented disputes over the reproducibility of a particular scientific phenomenon. In the 1660s, the Dutch scientist Christiaan Huygens built his own air pump in Amsterdam, the first one outside the... | Reproducibility | Wikipedia | 474 | 47651 | https://en.wikipedia.org/wiki/Reproducibility | Physical sciences | Science basics | Basics and measurement | vital_articles |
Terminology
Replicability and repeatability are related terms broadly or loosely synonymous with reproducibility (for example, among the general public), but they are often usefully differentiated in more precise senses, as follows.
Two major steps are naturally distinguished in connection with reproducibility of expe... | Reproducibility | Wikipedia | 406 | 47651 | https://en.wikipedia.org/wiki/Reproducibility | Physical sciences | Science basics | Basics and measurement | vital_articles |
To make any research project computationally reproducible, general practice involves all data and files being clearly separated, labelled, and documented. All operations should be fully documented and automated as much as practicable, avoiding manual intervention where feasible. The workflow should be designed as a seq... | Reproducibility | Wikipedia | 474 | 47651 | https://en.wikipedia.org/wiki/Reproducibility | Physical sciences | Science basics | Basics and measurement | vital_articles |
In economics, concerns have been raised in relation to the credibility and reliability of published research. In other sciences, reproducibility is regarded as fundamental and is often a prerequisite to research being published, however in economic sciences it is not seen as a priority of the greatest importance. Most ... | Reproducibility | Wikipedia | 469 | 47651 | https://en.wikipedia.org/wiki/Reproducibility | Physical sciences | Science basics | Basics and measurement | vital_articles |
In March 1989, University of Utah chemists Stanley Pons and Martin Fleischmann reported the production of excess heat that could only be explained by a nuclear process ("cold fusion"). The report was astounding given the simplicity of the equipment: it was essentially an electrolysis cell containing heavy water and a p... | Reproducibility | Wikipedia | 370 | 47651 | https://en.wikipedia.org/wiki/Reproducibility | Physical sciences | Science basics | Basics and measurement | vital_articles |
A toxic heavy metal is a common but misleading term for a metal-like element noted for its potential toxicity. Not all heavy metals are toxic and some toxic metals are not heavy. Elements often discussed as toxic include cadmium, mercury and lead, all of which appear in the World Health Organization's list of 10 chemi... | Toxic heavy metal | Wikipedia | 504 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
Toxic metals are found naturally in the earth, and become concentrated as a result of human activities, or, in some cases geochemical processes, such as accumulation in peat soils that are then released when drained for agriculture. Common sources include fertilisers; aging water supply infrastructure; and microplastic... | Toxic heavy metal | Wikipedia | 269 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
Toxic metals enter plant, animal and human tissues via air inhalation, diet, and manual handling. Welding, galvanizing, brazing, and soldering exposes workers to fumes that may be inhaled and result in metal fume fever. Motor vehicle emissions are a major source of airborne contaminants including arsenic, cadmium, cob... | Toxic heavy metal | Wikipedia | 369 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
The toxic effects of arsenic, mercury and lead were known to the ancients but methodical studies of the overall toxicity of heavy metals appear to date from only 1868. In that year, Wanklyn and Chapman speculated on the adverse effects of the heavy metals "arsenic, lead, copper, zinc, iron and manganese" in drinking wa... | Toxic heavy metal | Wikipedia | 333 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
The first emperor of unified China, Qin Shi Huang, it is reported, died of ingesting mercury pills that were intended to give him eternal life. The phrase "mad as a hatter" is likely a reference to mercury poisoning among milliners (so-called "mad hatter disease"), as mercury-based compounds were once used in the manuf... | Toxic heavy metal | Wikipedia | 278 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
The adverse effects of lead were known to the ancients. In the 2nd century BC the Greek botanist Nicander described the colic and paralysis seen in lead-poisoned people. Dioscorides, a Greek physician who is thought to have lived in the 1st century CE, wrote that lead "makes the mind give way". Lead was used extensivel... | Toxic heavy metal | Wikipedia | 388 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
Chromium(III) compounds and chromium metal are not considered a health hazard, while the toxicity and carcinogenic properties of chromium(VI) have been known since at least the late 19th century. In 1890, Newman described the elevated cancer risk of workers in a chromate dye company. Chromate-induced dermatitis was rep... | Toxic heavy metal | Wikipedia | 440 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
In humans, heavy metal poisoning is generally treated by the administration of chelating agents. These are chemical compounds, such as (calcium disodium ethylenediaminetetraacetate) that convert heavy metals to chemically inert forms that can be excreted without further interaction with the body. Chelates are not with... | Toxic heavy metal | Wikipedia | 388 | 47671 | https://en.wikipedia.org/wiki/Toxic%20heavy%20metal | Physical sciences | Periodic table | Chemistry | vital_articles |
Cosmic rays or astroparticles are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's ... | Cosmic ray | Wikipedia | 374 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Composition
Of primary cosmic rays, which originate outside of Earth's atmosphere, about 99% are the bare nuclei of common atoms (stripped of their electron shells), and about 1% are solitary electrons (that is, one type of beta particle). Of the nuclei, about 90% are simple protons (i.e., hydrogen nuclei); 9% are alph... | Cosmic ray | Wikipedia | 378 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Energy
Cosmic rays attract great interest practically, due to the damage they inflict on microelectronics and life outside the protection of an atmosphere and magnetic field, and scientifically, because the energies of the most energetic ultra-high-energy cosmic rays have been observed to approach (This is slightly gr... | Cosmic ray | Wikipedia | 416 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
In 1912, Victor Hess carried three enhanced-accuracy Wulf electrometers to an altitude of 5,300 metres in a free balloon flight. He found the ionization rate increased to twice the rate at ground level. Hess ruled out the Sun as the radiation's source by making a balloon ascent during a near-total eclipse. With the moo... | Cosmic ray | Wikipedia | 312 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
In the 1920s, the term cosmic ray was coined by Robert Millikan who made measurements of ionization due to cosmic rays from deep under water to high altitudes and around the globe. Millikan believed that his measurements proved that the primary cosmic rays were gamma rays; i.e., energetic photons. And he proposed a the... | Cosmic ray | Wikipedia | 387 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
During a test of his equipment for measuring the east–west effect, Rossi observed that the rate of near-simultaneous discharges of two widely separated Geiger counters was larger than the expected accidental rate. In his report on the experiment, Rossi wrote "... it seems that once in a while the recording equipment is... | Cosmic ray | Wikipedia | 317 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Energy distribution
Measurements of the energy and arrival directions of the ultra-high-energy primary cosmic rays by the techniques of density sampling and fast timing of extensive air showers were first carried out in 1954 by members of the Rossi Cosmic Ray Group at the Massachusetts Institute of Technology. The expe... | Cosmic ray | Wikipedia | 496 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Sources
Early speculation on the sources of cosmic rays included a 1934 proposal by Baade and Zwicky suggesting cosmic rays originated from supernovae. A 1948 proposal by Horace W. Babcock suggested that magnetic variable stars could be a source of cosmic rays. Subsequently, Sekido et al. (1951) identified the Crab Neb... | Cosmic ray | Wikipedia | 458 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
In 2017, the Pierre Auger Collaboration published the observation of a weak anisotropy in the arrival directions of the highest energy cosmic rays. Since the Galactic Center is in the deficit region, this anisotropy can be interpreted as evidence for the extragalactic origin of cosmic rays at the highest energies. This... | Cosmic ray | Wikipedia | 482 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
This abundance difference is a result of the way in which secondary cosmic rays are formed. Carbon and oxygen nuclei collide with interstellar matter to form lithium, beryllium, and boron, an example of cosmic ray spallation. Spallation is also responsible for the abundances of scandium, titanium, vanadium, and mangane... | Cosmic ray | Wikipedia | 464 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
There is no evidence of complex antimatter atomic nuclei, such as antihelium nuclei (i.e., anti-alpha particles), in cosmic rays. These are actively being searched for. A prototype of the AMS-02 designated AMS-01, was flown into space aboard the on STS-91 in June 1998. By not detecting any antihelium at all, the AMS-0... | Cosmic ray | Wikipedia | 422 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
The flux of incoming cosmic rays at the upper atmosphere is dependent on the solar wind, the Earth's magnetic field, and the energy of the cosmic rays. At distances of ≈94 AU from the Sun, the solar wind undergoes a transition, called the termination shock, from supersonic to subsonic speeds. The region between the ter... | Cosmic ray | Wikipedia | 512 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
There are two main classes of detection methods. First, the direct detection of the primary cosmic rays in space or at high altitude by balloon-borne instruments. Second, the indirect detection of secondary particle, i.e., extensive air showers at higher energies. While there have been proposals and prototypes for spac... | Cosmic ray | Wikipedia | 485 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Indirect detection
There are several ground-based methods of detecting cosmic rays currently in use, which can be divided in two main categories: the detection of secondary particles forming extensive air showers (EAS) by various types of particle detectors, and the detection of electromagnetic radiation emitted by EAS... | Cosmic ray | Wikipedia | 455 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
The first detection method in the second category is called the air Cherenkov telescope, designed to detect low-energy (<200 GeV) cosmic rays by means of analyzing their Cherenkov radiation, which for cosmic rays are gamma rays emitted as they travel faster than the speed of light in their medium, the atmosphere. While... | Cosmic ray | Wikipedia | 387 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Role in ambient radiation
Cosmic rays constitute a fraction of the annual radiation exposure of human beings on the Earth, averaging 0.39mSv out of a total of 3mSv per year (13% of total background) for the Earth's population. However, the background radiation from cosmic rays increases with altitude, from 0.3mSv per y... | Cosmic ray | Wikipedia | 485 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Galactic cosmic rays are one of the most important barriers standing in the way of plans for interplanetary travel by crewed spacecraft. Cosmic rays also pose a threat to electronics placed aboard outgoing probes. In 2010, a malfunction aboard the Voyager 2 space probe was credited to a single flipped bit, probably cau... | Cosmic ray | Wikipedia | 410 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Danish physicist Henrik Svensmark has controversially argued that because solar variation modulates the cosmic ray flux on Earth, it would consequently affect the rate of cloud formation and hence be an indirect cause of global warming. Svensmark is one of several scientists outspokenly opposed to the mainstream scient... | Cosmic ray | Wikipedia | 438 | 47687 | https://en.wikipedia.org/wiki/Cosmic%20ray | Physical sciences | Basics_3 | null | vital_articles |
Corals are colonial marine invertebrates within the subphylum Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.
A coral "group" ... | Coral | Wikipedia | 468 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
Taxonomy
The classification of corals has been discussed for millennia, owing to having similarities to both plants and animals. Aristotle's pupil Theophrastus described the red coral, korallion, in his book on stones, implying it was a mineral, but he described it as a deep-sea plant in his Enquiries on Plants, where ... | Coral | Wikipedia | 463 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
The delineation of coral species is challenging as hypotheses based on morphological traits contradict hypotheses formed via molecular tree-based processes. As of 2020, there are 2175 identified separate coral species, 237 of which are currently endangered, making distinguishing corals to be the utmost of importance in... | Coral | Wikipedia | 506 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
Environmental factors, such as the rise of temperatures and acid levels in our oceans account for some speciation of corals in the form of species lost. Various coral species have heat shock proteins (HSP) that are also in the category of DE across species. These HSPs help corals combat the increased temperatures they ... | Coral | Wikipedia | 492 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
The sac-like body built up in this way is attached to a hard surface, which in hard corals are cup-shaped depressions in the skeleton known as corallites. At the center of the upper end of the sac lies the only opening called the mouth, surrounded by a circle of tentacles which resemble glove fingers. The tentacles are... | Coral | Wikipedia | 498 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
Soft corals vary considerably in form, and most are colonial. A few soft corals are stolonate, but the polyps of most are connected by sheets of tissue called coenosarc, and in some species these sheets are thick and the polyps deeply embedded in them. Some soft corals encrust other sea objects or form lobes. Others ar... | Coral | Wikipedia | 477 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
Intracellular symbionts
Many corals, as well as other cnidarian groups such as sea anemones form a symbiotic relationship with a class of dinoflagellate algae, zooxanthellae of the genus Symbiodinium, which can form as much as 30% of the tissue of a polyp. Typically, each polyp harbors one species of alga, and coral sp... | Coral | Wikipedia | 245 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
The zooxanthellae benefit from a safe place to live and consume the polyp's carbon dioxide, phosphate and nitrogenous waste. Stressed corals will eject their zooxanthellae, a process that is becoming increasingly common due to strain placed on coral by rising ocean temperatures. Mass ejections are known as coral bleach... | Coral | Wikipedia | 414 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
About 75% of all hermatypic corals "broadcast spawn" by releasing gametes—eggs and sperm—into the water where they meet and fertilize to spread offspring. Corals often synchronize their time of spawning. This reproductive synchrony is essential so that male and female gametes can meet. Spawning frequently takes place i... | Coral | Wikipedia | 456 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
Studies suggest that light pollution desynchronizes spawning in some coral species.
In areas such as the Red Sea, as many as 10 out of 50 species may be showing spawning asynchrony, compared to 30 years ago. The establishment of new corals in the area has decreased and in some cases ceased. The area was previously cons... | Coral | Wikipedia | 509 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
Division forms two polyps that each become as large as the original. Longitudinal division begins when a polyp broadens and then divides its coelenteron (body), effectively splitting along its length. The mouth divides and new tentacles form. The two polyps thus created then generate their missing body parts and exoske... | Coral | Wikipedia | 486 | 47700 | https://en.wikipedia.org/wiki/Coral | Biology and health sciences | Cnidarians | null | vital_articles |
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