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Termites also contain methanogenic microorganisms in their gut. However, some of these microorganisms are so unique that they live nowhere else in the world except in the third gut of termites. These microorganisms also break down biotic components to produce ethanol, as well as methane byproduct. However, unlike rumin... | Methane emissions | Wikipedia | 396 | 53830256 | https://en.wikipedia.org/wiki/Methane%20emissions | Physical sciences | Climate change | Earth science |
Landfills
Due to the large collections of organic matter and availability of anaerobic conditions, landfills are the third largest source of atmospheric methane in the United States, accounting for roughly 18.2% of methane emissions globally in 2014. When waste is first added to a landfill, oxygen is abundant and thus... | Methane emissions | Wikipedia | 486 | 53830256 | https://en.wikipedia.org/wiki/Methane%20emissions | Physical sciences | Climate change | Earth science |
Oil and natural gas supply chain
Methane is a primary component of natural gas, and thus during the production, processing, storage, transmission, and distribution of natural gas, a significant amount of methane is lost into the atmosphere.
According to the EPA Inventory of U.S Greenhouse Gas Emissions and Sinks: 199... | Methane emissions | Wikipedia | 495 | 53830256 | https://en.wikipedia.org/wiki/Methane%20emissions | Physical sciences | Climate change | Earth science |
At high pressures, such as are found on the bottom of the ocean, methane forms a solid clathrate with water, known as methane hydrate. An unknown, but possibly very large quantity of methane is trapped in this form in ocean sediments. Researchers are investigating possible changes in this process (clathrate gun hypothe... | Methane emissions | Wikipedia | 459 | 53830256 | https://en.wikipedia.org/wiki/Methane%20emissions | Physical sciences | Climate change | Earth science |
Uncertainties in methane emissions, including so-called "super-emitter" fossil extractions and unexplained atmospheric fluctuations, highlight the need for improved monitoring at both regional and global scale. Satellites have recently begun to come online with capability to measure methane and other more powerful gree... | Methane emissions | Wikipedia | 510 | 53830256 | https://en.wikipedia.org/wiki/Methane%20emissions | Physical sciences | Climate change | Earth science |
Approaches to reduce emissions
Natural gas industries
About 40% of methane emissions from the fossil fuel industry could be "eliminated at no net cost for firms", according to the International Energy Agency (IEA) by using existing technologies. Forty percent represents 9% of all human methane emissions.
To reduce ... | Methane emissions | Wikipedia | 400 | 53830256 | https://en.wikipedia.org/wiki/Methane%20emissions | Physical sciences | Climate change | Earth science |
Crops and soils
In order to reduce effects on methane oxidation in soil, several steps can be taken. Controlling the usage of nitrogen enhancing fertilizer and reducing the amount of nitrogen pollution into the air can both lower inhibition of methane oxidation. Additionally, using drier growing conditions for crops s... | Methane emissions | Wikipedia | 365 | 53830256 | https://en.wikipedia.org/wiki/Methane%20emissions | Physical sciences | Climate change | Earth science |
Antarctic fish is a common name for a variety of fish that inhabit the Southern Ocean. There are relatively few families in this region, the most species-rich being the Liparidae (snailfishes), followed by Nototheniidae (cod icefishes). The latter is one of eight different families that belong to the suborder Nototheni... | Antarctic fishes | Wikipedia | 465 | 49980572 | https://en.wikipedia.org/wiki/Antarctic%20fishes | Biology and health sciences | Acanthomorpha | Animals |
Buoyancy
Notothenioid fish dominate the Southern Ocean diversity and biomass largely because of the pelagization by some species. Most fish are benthic and consequently, spend their lives on the seafloor. Notothenioids are found in many different niches like semipelagic, cryopelagic, pelagic, and benthic zones. Specie... | Antarctic fishes | Wikipedia | 452 | 49980572 | https://en.wikipedia.org/wiki/Antarctic%20fishes | Biology and health sciences | Acanthomorpha | Animals |
Heat shock proteins
Heat shock proteins (HSPs) are expressed during exposure to high temperatures and is a characteristic held by most organisms. In some species of nototheniids, this trait is not expressed. The trait is not expressed because of the extreme cold of the Southern Oceans leading to upregulation of Hsp70.... | Antarctic fishes | Wikipedia | 427 | 49980572 | https://en.wikipedia.org/wiki/Antarctic%20fishes | Biology and health sciences | Acanthomorpha | Animals |
Life cycle
Notothenioids have a lifespan of an estimated ten years and reach sexual maturity at ages 3–4 years. Notothenioids are thought to spawn annually while sex organ maturation takes place every other year. Spawning generally takes place during fall or winter if taking place in seasonal ice habitats while spawni... | Antarctic fishes | Wikipedia | 455 | 49980572 | https://en.wikipedia.org/wiki/Antarctic%20fishes | Biology and health sciences | Acanthomorpha | Animals |
Antarctic fish speciation coincides with the separation of Antarctica from Gondwana, a continent composed of Antarctica, Australia, South America and Africa. The temperate, shallow seas hosted a variety of marine life. The close relatives of Antarctic notothenioids, like Halaphritis, Bovichtus and Pseudaphritis, inhabi... | Antarctic fishes | Wikipedia | 231 | 49980572 | https://en.wikipedia.org/wiki/Antarctic%20fishes | Biology and health sciences | Acanthomorpha | Animals |
ITU-R Recommendation BT.2100, more commonly known by the abbreviations Rec. 2100 or BT.2100, introduced high-dynamic-range television (HDR-TV) by recommending the use of the perceptual quantizer (PQ [SMPTE ST 2084]) or hybrid log–gamma (HLG) transfer functions instead of the traditional "gamma" previously used for SDR-... | Rec. 2100 | Wikipedia | 492 | 51001497 | https://en.wikipedia.org/wiki/Rec.%202100 | Physical sciences | Basics | Physics |
Frame rate
Rec. 2100 specifies the following frame rates: 120p, 119.88p, 100p, 60p, 59.94p, 50p, 30p, 29.97p, 25p, 24p, 23.976p. Only progressive scan frame rates are allowed.
Digital representation
Rec. 2100 specifies a bit depth of either 10-bits per sample or 12-bits per sample, with either narrow range or full ran... | Rec. 2100 | Wikipedia | 449 | 51001497 | https://en.wikipedia.org/wiki/Rec.%202100 | Physical sciences | Basics | Physics |
Before Rec. BT.2020 the chroma sample location that was in use was center left. But in H.265 (2018-02) top-left chroma siting was mandated for BT.2020-2 and BT.2100-1, that must be described in VUI (video usability information) as such. First value of VUI should be 2 for top-left chroma and 0 for center left. Blu-ray ... | Rec. 2100 | Wikipedia | 112 | 51001497 | https://en.wikipedia.org/wiki/Rec.%202100 | Physical sciences | Basics | Physics |
Aphelida is a phylum of Fungi that appears to be the sister to true fungi.
Taxonomy
Phylum Aphelidiomycota Tedersoo 2018 [Aphelida Karpov, Aleoshin & Mikhailov 2014]
Class Aphelidiomycetes Tedersoo 2018 [Aphelidea Gromov 2000]
Order Aphelidiales Tedersoo et al. 2018 [Aphelidida Gromov 2000 non Cavalier-Smith 2012]
... | Aphelida | Wikipedia | 188 | 51011436 | https://en.wikipedia.org/wiki/Aphelida | Biology and health sciences | Basics | Plants |
SN 1972E was a supernova in the galaxy NGC 5253 that was discovered 13 May 1972 with an apparent B magnitude of about 8.5, shortly after it had reached its maximum brightness. In terms of apparent brightness, it was the second-brightest supernova of any kind (fainter only than SN 1987A) of the 20th century. It was ob... | SN 1972E | Wikipedia | 460 | 39577606 | https://en.wikipedia.org/wiki/SN%201972E | Physical sciences | Notable transient events | Astronomy |
Symmetries in quantum mechanics describe features of spacetime and particles which are unchanged under some transformation, in the context of quantum mechanics, relativistic quantum mechanics and quantum field theory, and with applications in the mathematical formulation of the standard model and condensed matter physi... | Symmetry in quantum mechanics | Wikipedia | 481 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
are considered, where denotes a unitary operator. Unitarity is generally required for operators representing transformations of space, time, and spin, since the norm of a state (representing the total probability of finding the particle somewhere with some spin) must be invariant under these transformations. The inver... | Symmetry in quantum mechanics | Wikipedia | 231 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
Let be a Lie group, which is a group that locally is parameterized by a finite number of real continuously varying parameters . In more mathematical language, this means that is a smooth manifold that is also a group, for which the group operations are smooth.
the dimension of the group, , is the number of parameter... | Symmetry in quantum mechanics | Wikipedia | 458 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
A representation which cannot be decomposed into a direct sum of other representations, is called irreducible. It is conventional to label irreducible representations by a superscripted number in brackets, as in , or if there is more than one number, we write . | Symmetry in quantum mechanics | Wikipedia | 55 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
There is an additional subtlety that arises in quantum theory, where two vectors that differ by multiplication by a scalar represent the same physical state. Here, the pertinent notion of representation is a projective representation, one that only satisfies the composition law up to a scalar. In the context of quantum... | Symmetry in quantum mechanics | Wikipedia | 504 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
More generally for rotations about an axis defined by , the rotation matrix elements are:
where is the Kronecker delta, and is the Levi-Civita symbol.
It is not as obvious how to determine the rotational operator compared to space and time translations. We may consider a special case (rotations about the , , or -ax... | Symmetry in quantum mechanics | Wikipedia | 482 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
Evaluating the exponential for a given z-projection spin quantum number s gives a (2s + 1)-dimensional spin matrix. This can be used to define a spinor as a column vector of 2s + 1 components which transforms to a rotated coordinate system according to the spin matrix at a fixed point in space.
For the simplest non-tr... | Symmetry in quantum mechanics | Wikipedia | 495 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
A boost with velocity in the x, y, or z directions given by the standard Cartesian basis vector , are the boost transformation matrices. These matrices and the corresponding generators are the remaining three group elements and generators of the Lorentz group:
The boost matrices act on any four vector A = (A0, A1, ... | Symmetry in quantum mechanics | Wikipedia | 492 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
In relativistic quantum mechanics, wavefunctions are no longer single-component scalar fields, but now 2(2s + 1) component spinor fields, where s is the spin of the particle. The transformations of these functions in spacetime are given below.
Under a proper orthochronous Lorentz transformation in Minkowski space, al... | Symmetry in quantum mechanics | Wikipedia | 512 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
In the context of the Dirac equation and Weyl equation, the Weyl spinors satisfying the Weyl equation transform under the simplest irreducible spin representations of the Lorentz group, since the spin quantum number in this case is the smallest non-zero number allowed: 1/2. The 2-component left-handed Weyl spinor tran... | Symmetry in quantum mechanics | Wikipedia | 510 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
Symmetries in quantum field theory and particle physics
Unitary groups in quantum field theory
Group theory is an abstract way of mathematically analyzing symmetries. Unitary operators are paramount to quantum theory, so unitary groups are important in particle physics. The group of N dimensional unitary square matri... | Symmetry in quantum mechanics | Wikipedia | 509 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
U(3) and SU(3)
The eight Gell-Mann matrices (see article for them and the structure constants) are important for quantum chromodynamics. They originally arose in the theory SU(3) of flavor which is still of practical importance in nuclear physics. They are the generators for the SU(3) group, so an element of SU(3) ca... | Symmetry in quantum mechanics | Wikipedia | 509 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
CPT theorem
CP violation
PT symmetry
Lorentz violation
Gauge theory
In quantum electrodynamics, the local symmetry group is U(1) and is abelian. In quantum chromodynamics, the local symmetry group is SU(3) and is non-abelian.
The electromagnetic interaction is mediated by photons, which have no electric charge. The ... | Symmetry in quantum mechanics | Wikipedia | 439 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
The concept of exchange symmetry is derived from a fundamental postulate of quantum statistics, which states that no observable physical quantity should change after exchanging two identical particles. It states that because all observables are proportional to for a system of identical particles, the wave function mu... | Symmetry in quantum mechanics | Wikipedia | 455 | 39580830 | https://en.wikipedia.org/wiki/Symmetry%20in%20quantum%20mechanics | Physical sciences | Quantum mechanics | Physics |
Unbiunium, also known as eka-actinium or element 121, is a hypothetical chemical element; it has symbol Ubu and atomic number 121. Unbiunium and Ubu are the temporary systematic IUPAC name and symbol respectively, which are used until the element is discovered, confirmed, and a permanent name is decided upon. In the pe... | Unbiunium | Wikipedia | 378 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Fusion reactions producing superheavy elements can be divided into "hot" and "cold" fusion, depending on the excitation energy of the compound nucleus produced. In hot fusion reactions, very light, high-energy projectiles are accelerated toward very heavy targets (actinides), giving rise to compound nuclei at high exci... | Unbiunium | Wikipedia | 400 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Because of the current impossibility of synthesizing elements beyond californium (Z = 98) in sufficient quantities to create a target, with einsteinium (Z = 99) targets being currently considered, the practical synthesis of elements beyond oganesson requires heavier projectiles, such as titanium-50, chromium-54, iron-5... | Unbiunium | Wikipedia | 435 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Because the cross sections of these fusion-evaporation reactions increase with the asymmetry of the reaction, titanium would be a better projectile than chromium for the synthesis of element 121, though this necessitates an einsteinium target. This poses severe challenges due to the significant heating and damage of th... | Unbiunium | Wikipedia | 345 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Should the synthesis of unbiunium isotopes in such a reaction be successful, the resulting nuclei would decay through isotopes of ununennium that could be produced by cross-bombardments in the 248Cm+51V or 249Bk+50Ti reactions, down through known isotopes of tennessine and moscovium synthesized in the 249Bk+48Ca and 24... | Unbiunium | Wikipedia | 363 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Nuclear stability and isotopes
The stability of nuclei decreases greatly with the increase in atomic number after curium, element 96, whose half-life is four orders of magnitude longer than that of any currently known higher-numbered element. All isotopes with an atomic number above 101 undergo radioactive decay with ... | Unbiunium | Wikipedia | 510 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Predicted chemistry
Unbiunium is predicted to be the first element of an unprecedentedly long transition series, called the superactinides in analogy to the earlier actinides. While its behavior is not likely to be very distinct from lanthanum and actinium, it is likely to pose a limit to the applicability of the perio... | Unbiunium | Wikipedia | 486 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Unbiunium is expected to fill the 8p1/2 orbital due to its relativistic stabilization, with a configuration of [Og] 8s2 8p1. Nevertheless, the [Og] 7d1 8s2 configuration, which would be analogous to lanthanum and actinium, is expected to be a low-lying excited state at only 0.412 eV, and the expected [Og] 5g1 8s2 confi... | Unbiunium | Wikipedia | 242 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Despite the change in electron configuration and possibility of using the 5g shell, unbiunium is not expected to behave chemically very differently from lanthanum and actinium. A 2016 calculation on unbiunium monofluoride (UbuF) showed similarities between the valence orbitals of unbiunium in this molecule and those of... | Unbiunium | Wikipedia | 417 | 50007204 | https://en.wikipedia.org/wiki/Unbiunium | Physical sciences | Periods | Chemistry |
Hydraulic fracturing is a well stimulation technique involving the fracturing of formations in bedrock by a pressurized liquid. The process involves the high-pressure injection of "fracking fluid" (primarily water, containing sand or other proppants suspended with the aid of thickening agents) into a wellbore to create... | Fracking | Wikipedia | 495 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Increases in seismic activity following hydraulic fracturing along dormant or previously unknown faults are sometimes caused by the deep-injection disposal of hydraulic fracturing flowback (a byproduct of hydraulically fractured wells), and produced formation brine (a byproduct of both fractured and non-fractured oil a... | Fracking | Wikipedia | 459 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Fracturing as a method to stimulate shallow, hard rock oil wells dates back to the 1860s. Dynamite or nitroglycerin detonations were used to increase oil and natural gas production from petroleum bearing formations. On 24 April 1865, US Civil War veteran Col. Edward A. L. Roberts received a patent for an "exploding tor... | Fracking | Wikipedia | 489 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
In the Soviet Union, the first hydraulic proppant fracturing was carried out in 1952. Other countries in Europe and Northern Africa subsequently employed hydraulic fracturing techniques including Norway, Poland, Czechoslovakia (before 1989), Yugoslavia (before 1991), Hungary, Austria, France, Italy, Bulgaria, Romania, ... | Fracking | Wikipedia | 500 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
In 1976, the United States government started the Eastern Gas Shales Project, which included numerous public-private hydraulic fracturing demonstration projects. During the same period, the Gas Research Institute, a gas industry research consortium, received approval for research and funding from the Federal Energy Reg... | Fracking | Wikipedia | 345 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Method
A hydraulic fracture is formed by pumping fracturing fluid into a wellbore at a rate sufficient to increase pressure at the target depth (determined by the location of the well casing perforations), to exceed that of the fracture gradient (pressure gradient) of the rock. The fracture gradient is defined as press... | Fracking | Wikipedia | 383 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Hydraulic-fracturing equipment used in oil and natural gas fields usually consists of a slurry blender, one or more high-pressure, high-volume fracturing pumps (typically powerful triplex or quintuplex pumps) and a monitoring unit. Associated equipment includes fracturing tanks, one or more units for storage and handli... | Fracking | Wikipedia | 502 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Water-soluble gelling agents (such as guar gum) increase viscosity and efficiently deliver proppant into the formation.
Fluid is typically a slurry of water, proppant, and chemical additives. Additionally, gels, foams, and compressed gases, including nitrogen, carbon dioxide and air can be injected. Typically, 90% of ... | Fracking | Wikipedia | 461 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Water is mixed with sand and chemicals to create hydraulic fracturing fluid. Approximately 40,000 gallons of chemicals are used per fracturing.
A typical fracture treatment uses between 3 and 12 additive chemicals. Although there may be unconventional fracturing fluids, typical chemical additives can include one or mor... | Fracking | Wikipedia | 328 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Typical fluid types are:
Conventional linear gels. These gels are cellulose derivative (carboxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose), guar or its derivatives (hydroxypropyl guar, carboxymethyl hydroxypropyl guar), mixed w... | Fracking | Wikipedia | 313 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
For slickwater fluids the use of sweeps is common. Sweeps are temporary reductions in the proppant concentration, which help ensure that the well is not overwhelmed with proppant. As the fracturing process proceeds, viscosity-reducing agents such as oxidizers and enzyme breakers are sometimes added to the fracturing fl... | Fracking | Wikipedia | 316 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Injection of radioactive tracers along with the fracturing fluid is sometimes used to determine the injection profile and location of created fractures. Radiotracers are selected to have the readily detectable radiation, appropriate chemical properties, and a half life and toxicity level that will minimize initial and ... | Fracking | Wikipedia | 384 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Microseismic mapping is very similar geophysically to seismology. In earthquake seismology, seismometers scattered on or near the surface of the earth record S-waves and P-waves that are released during an earthquake event. This allows for motion along the fault plane to be estimated and its location in the Earth's sub... | Fracking | Wikipedia | 502 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
In North America, shale reservoirs such as the Bakken, Barnett, Montney, Haynesville, Marcellus, and most recently the Eagle Ford, Niobrara and Utica shales are drilled horizontally through the producing intervals, completed and fractured. The method by which the fractures are placed along the wellbore is most commonly... | Fracking | Wikipedia | 364 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Uses
Hydraulic fracturing is used to increase the rate at which substances such as petroleum or natural gas can be recovered from subterranean natural reservoirs. Reservoirs are typically porous sandstones, limestones or dolomite rocks, but also include "unconventional reservoirs" such as shale rock or coal beds. Hydr... | Fracking | Wikipedia | 386 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Economic effects
Hydraulic fracturing has been seen as one of the key methods of extracting unconventional oil and unconventional gas resources. According to the International Energy Agency, the remaining technically recoverable resources of shale gas are estimated to amount to , tight gas to , and coalbed methane to .... | Fracking | Wikipedia | 469 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
The Energy Information Administration of the US Department of Energy estimates that 45% of US gas supply will come from shale gas by 2035 (with the vast majority of this replacing conventional gas, which has a lower greenhouse-gas footprint).
Public debate
Politics and public policy
Popular movement and civil societ... | Fracking | Wikipedia | 335 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
U.S. government and Corporate lobbying
The United States Department of State established the Global Shale Gas Initiative to persuade governments around the world to give concessions to the major oil and gas companies to set up fracking operations. A document from the United States diplomatic cables leak show that, as p... | Fracking | Wikipedia | 485 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Documentary films
Josh Fox's 2010 Academy Award nominated film Gasland became a center of opposition to hydraulic fracturing of shale. The movie presented problems with groundwater contamination near well sites in Pennsylvania, Wyoming and Colorado. Energy in Depth, an oil and gas industry lobbying group, called the fi... | Fracking | Wikipedia | 460 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Research issues
Typically the funding source of the research studies is a focal point of controversy. Concerns have been raised about research funded by foundations and corporations, or by environmental groups, which can at times lead to at least the appearance of unreliable studies. Several organizations, researchers,... | Fracking | Wikipedia | 499 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
A 2017 study in The American Economic Review found that "additional well pads drilled within 1 kilometer of a community water system intake increases shale gas-related contaminants in drinking water."
A 2022 study conduced by Harvard T.H. Chan School of Public Health and published in Nature Energy found that elderly p... | Fracking | Wikipedia | 460 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
In December 2016 the United States Environmental Protection Agency (EPA) issued the "Hydraulic Fracturing for Oil and Gas: Impacts from the Hydraulic Fracturing Water Cycle on Drinking Water Resources in the United States (Final Report)." The EPA found scientific evidence that hydraulic fracturing activities can impact... | Fracking | Wikipedia | 436 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
In the United States over 12 million acres are being used for fossil fuels. About of land is needed per each drill pad for surface installations. This is equivalent of six Yellowstone National Parks. Well pad and supporting structure construction significantly fragments landscapes which likely has negative effects on ... | Fracking | Wikipedia | 457 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Per- and polyfluoroalkyl substances also known as "PFAS" or "forever chemicals" have been linked to cancer and birth defects. The chemicals used in fracking stay in the environment. Once there those chemicals will eventually break down into PFAS. These chemicals can escape from drilling sites and into the groundwater. ... | Fracking | Wikipedia | 429 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
The European Union has adopted a recommendation for minimum principles for using high-volume hydraulic fracturing. Its regulatory regime requires full disclosure of all additives. In the United States, the Ground Water Protection Council launched FracFocus.org, an online voluntary disclosure database for hydraulic frac... | Fracking | Wikipedia | 170 | 32544339 | https://en.wikipedia.org/wiki/Fracking | Technology | Fuel | null |
Tamisiocarididae is a family of radiodonts, extinct marine animals related to arthropods, that bore finely-spined appendages that were presumably used in filter-feeding. When first discovered, the clade was named Cetiocaridae after a speculative evolution artwork, Bearded Ceticaris by John Meszaros, that depicted a hyp... | Tamisiocarididae | Wikipedia | 495 | 42354952 | https://en.wikipedia.org/wiki/Tamisiocarididae | Biology and health sciences | Fossil arthropods | Animals |
In the mathematical discipline of graph theory, a rainbow matching in an edge-colored graph is a matching in which all the edges have distinct colors.
Definition
Given an edge-colored graph , a rainbow matching in is a set of pairwise non-adjacent edges, that is, no two edges share a common vertex, such that all the... | Rainbow matching | Wikipedia | 496 | 42366612 | https://en.wikipedia.org/wiki/Rainbow%20matching | Mathematics | Graph theory | null |
Every proper edge-coloring of has a rainbow matching of size .
Every proper edge-coloring of has a rainbow matching of size
Every proper edge-coloring of has a rainbow matching of size .
Every proper edge-coloring of has a rainbow matching of size .
Every proper edge-coloring of has a rainbow matching of ... | Rainbow matching | Wikipedia | 486 | 42366612 | https://en.wikipedia.org/wiki/Rainbow%20matching | Mathematics | Graph theory | null |
In general graphs
In general graphs, matchings are no longer sufficient. When is even, one can add to Drisko's example the matching and get a family of matchings without any rainbow matching.
Aharoni, Berger, Chudnovsky, Howard and Seymour proved that, in a general graph, matchings (=colors) are always sufficien... | Rainbow matching | Wikipedia | 448 | 42366612 | https://en.wikipedia.org/wiki/Rainbow%20matching | Mathematics | Graph theory | null |
For every edge in , let be a vector of size , where for each vertex in , element in equals 1 if is adjacent to , and 0 otherwise (so each vector has 2 ones and -2 zeros). Every fractional matching corresponds to a conical combination of edges, in which each element is at most 1. A conical combination in which ea... | Rainbow matching | Wikipedia | 398 | 42366612 | https://en.wikipedia.org/wiki/Rainbow%20matching | Mathematics | Graph theory | null |
An r-partite hypergraph is an -uniform hypergraph in which the vertices are partitioned into disjoint sets and each hyperedge contains exactly one vertex of each set (so a 2-partite hypergraph is a just bipartite graph). Let be any positive integer. Any family of fractional-matchings (=colors) of size at least in a... | Rainbow matching | Wikipedia | 235 | 42366612 | https://en.wikipedia.org/wiki/Rainbow%20matching | Mathematics | Graph theory | null |
Arenicola, also known as sandworms, is a genus of capitellid annelid worms comprising the lugworms and black lugs.
Species
The following species are recognised in the genus Arenicola:
Arenicola brasiliensis Nonato, 1958
Arenicola cristata Stimpson, 1856
Arenicola defodiens Cadman & Nelson-Smith, 1993
Arenicola gla... | Arenicola | Wikipedia | 512 | 38155804 | https://en.wikipedia.org/wiki/Arenicola | Biology and health sciences | Lophotrochozoa | Animals |
In popular culture
A singing lugworm figures in The Man Who Dreamed of Faeryland by William Butler Yeats:
Cartoonist Piers Baker created a syndicated comic strip called Ollie and Quentin, with a buddy storyline about Ollie, a seagull and Quentin, a lugworm. The strip originated in the UK in 2002, with King Features S... | Arenicola | Wikipedia | 106 | 38155804 | https://en.wikipedia.org/wiki/Arenicola | Biology and health sciences | Lophotrochozoa | Animals |
In physics and geometry, there are two closely related vector spaces, usually three-dimensional but in general of any finite dimension.
Position space (also real space or coordinate space) is the set of all position vectors r in Euclidean space, and has dimensions of length; a position vector defines a point in space. ... | Position and momentum spaces | Wikipedia | 455 | 36740699 | https://en.wikipedia.org/wiki/Position%20and%20momentum%20spaces | Physical sciences | Quantum mechanics | Physics |
Most often in Lagrangian mechanics, the Lagrangian L(q, dq/dt, t) is in configuration space, where q = (q1, q2,..., qn) is an n-tuple of the generalized coordinates. The Euler–Lagrange equations of motion are
(One overdot indicates one time derivative). Introducing the definition of canonical momentum for each general... | Position and momentum spaces | Wikipedia | 445 | 36740699 | https://en.wikipedia.org/wiki/Position%20and%20momentum%20spaces | Physical sciences | Quantum mechanics | Physics |
In quantum mechanics, a particle is described by a quantum state. This quantum state can be represented as a superposition of basis states. In principle one is free to choose the set of basis states, as long as they span the state space. If one chooses the (generalized) eigenfunctions of the position operator as a set ... | Position and momentum spaces | Wikipedia | 485 | 36740699 | https://en.wikipedia.org/wiki/Position%20and%20momentum%20spaces | Physical sciences | Quantum mechanics | Physics |
and eigenvalues r. So a similar decomposition of can be made in terms of the eigenfunctions of this operator, which turns out to be the inverse Fourier transform,
Unitary equivalence
The position and momentum operators are unitarily equivalent, with the unitary operator being given explicitly by the Fourier transfo... | Position and momentum spaces | Wikipedia | 337 | 36740699 | https://en.wikipedia.org/wiki/Position%20and%20momentum%20spaces | Physical sciences | Quantum mechanics | Physics |
Euharamiyida also known as Eleutherodontida, is clade of early mammals or mammal-like cynodonts from the Middle Jurassic to Early Cretaceous of Eurasia and possibly North America. The group is sometimes considered a sister group to Multituberculata, or part of an earlier divergence within the synapsid line. It is dispu... | Euharamiyida | Wikipedia | 386 | 43801098 | https://en.wikipedia.org/wiki/Euharamiyida | Biology and health sciences | Stem-mammals | Animals |
Vacuum drying is the mass transfer operation in which the moisture present in a substance, usually a wet solid, is removed by means of creating a vacuum.
In chemical processing industries like food processing, pharmacology, agriculture, and textiles, drying is an essential unit operation to remove moisture. Vacuum dr... | Vacuum drying | Wikipedia | 496 | 50054690 | https://en.wikipedia.org/wiki/Vacuum%20drying | Physical sciences | Phase separations | Chemistry |
Applications
Vacuum dryer can be used to dry heat sensitive hygroscopic and toxic materials. If the feed for drying is a solution, it can be dried using vacuum dryer as the solvent can be recovered by condensation. To improve the quality of products, such as for fruit preservation, hybrid drying combining osmotic dehy... | Vacuum drying | Wikipedia | 84 | 50054690 | https://en.wikipedia.org/wiki/Vacuum%20drying | Physical sciences | Phase separations | Chemistry |
The garden eels are the subfamily Heterocongrinae in the conger eel family Congridae. The majority of the 36 known species of garden eels live in the Indo-Pacific, but can be found in warm ocean water worldwide. These small eels live in burrows on the sea floor and get their name from the behavior of poking their heads... | Heterocongrinae | Wikipedia | 166 | 32582674 | https://en.wikipedia.org/wiki/Heterocongrinae | Biology and health sciences | Anguilliformes | Animals |
In kinematics, Chasles' theorem, or Mozzi–Chasles' theorem, says that the most general rigid body displacement can be produced by a screw displacement. A direct Euclidean isometry in three dimensions involves a translation and a rotation. The screw displacement representation of the isometry decomposes the translation ... | Chasles' theorem (kinematics) | Wikipedia | 420 | 42392462 | https://en.wikipedia.org/wiki/Chasles%27%20theorem%20%28kinematics%29 | Physical sciences | Basics_4 | Physics |
Proof
Mozzi considers a rigid body undergoing first a rotation about an axis passing through the center of mass and then a translation of displacement D in an arbitrary direction. Any rigid motion can be accomplished in this way due to a theorem by Euler on the existence of an axis of rotation.
The displacement D of t... | Chasles' theorem (kinematics) | Wikipedia | 422 | 42392462 | https://en.wikipedia.org/wiki/Chasles%27%20theorem%20%28kinematics%29 | Physical sciences | Basics_4 | Physics |
A screw motion is the product of four non-collinear reflections, and thus . But according to the Mozzi-Chasles' theorem a screw motion can be decomposed into a commuting translation where is the axis of translation satisfying , and rotationwhere is the axis of rotation satisfying . The two bivector lines and are o... | Chasles' theorem (kinematics) | Wikipedia | 169 | 42392462 | https://en.wikipedia.org/wiki/Chasles%27%20theorem%20%28kinematics%29 | Physical sciences | Basics_4 | Physics |
An amoeba (; less commonly spelled ameba or amœba; : amoebas (less commonly, amebas) or amoebae (amebae) ), often called an amoeboid, is a type of cell or unicellular organism with the ability to alter its shape, primarily by extending and retracting pseudopods. Amoebae do not form a single taxonomic group; instead, th... | Amoeba | Wikipedia | 359 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
Amoeba do not have cell walls, which allows for free movement. Amoeba move and feed by using pseudopods, which are bulges of cytoplasm formed by the coordinated action of actin microfilaments pushing out the plasma membrane that surrounds the cell. The appearance and internal structure of pseudopods are used to disting... | Amoeba | Wikipedia | 475 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
The food sources of amoebae vary. Some amoebae are predatory and live by consuming bacteria and other protists. Some are detritivores and eat dead organic material.
Amoebae typically ingest their food by phagocytosis, extending pseudopods to encircle and engulf live prey or particles of scavenged material. Amoeboid ce... | Amoeba | Wikipedia | 390 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
The meiosis-specific recombinase, Dmc1, is required for efficient meiotic homologous recombination, and Dmc1 is expressed in Entamoeba histolytica. The purified Dmc1 from E. histolytica forms presynaptic filaments and catalyses ATP-dependent homologous DNA pairing and DNA strand exchange over at least several thousand ... | Amoeba | Wikipedia | 493 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
Amoeba have been found to harvest and grow the bacteria implicated in plague. Amoebae can likewise play host to microscopic organisms that are pathogenic to people and help in spreading such microbes. Bacterial pathogens (for example, Legionella) can oppose absorption of food when devoured by amoebae.
The currently gen... | Amoeba | Wikipedia | 332 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
In 1841, Félix Dujardin coined the term "sarcode" (from Greek σάρξ sarx, "flesh," and εἶδος eidos, "form") for the "thick, glutinous, homogeneous substance" which fills protozoan cell bodies. Although the term originally referred to the protoplasm of any protozoan, it soon came to be used in a restricted sense to desig... | Amoeba | Wikipedia | 508 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
Gymnamoebia : lobose naked amoebae. This polyphyletic group included the classic amorphous amoebae with big, blunt pseudopodia, such as Euamoebida, Leptomyxida, Acanthopodida, Echinamoebida, Entamoebida, etc.
Testacealobosia : lobose testate amoebae. This polyphyletic group included three unrelated lineages of amoeboz... | Amoeba | Wikipedia | 469 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
Actinopoda : spherical amoebae that float in the water column. This group included those organisms that have a heliozoan-type appearance, with radially positioned filopodia, reticulopodia or axopodia surrounding the cell body. These were the Radiolaria, Phaeodaria, Proteomyxidea (all three now in Rhizaria), Centroplast... | Amoeba | Wikipedia | 470 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
Today, amoebae are dispersed among many high-level taxonomic groups. The majority of traditional sarcodines are placed in two eukaryote supergroups: Amoebozoa and Rhizaria. The rest have been distributed among the excavates, opisthokonts, stramenopiles and minor clades.
Amoebozoa : includes all naked and testate lobo... | Amoeba | Wikipedia | 497 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
Rigifilida : a small order of filose amoebae previously interpreted as nucleariids. Together with the flagellate orders Mantamonadida and Diphylleida, it composes the CRuMs clade, positioned closest to Amorphea.
Breviatea : includes enigmatic free-living amoeboflagellates related to opisthokonts.
The following clado... | Amoeba | Wikipedia | 453 | 43815710 | https://en.wikipedia.org/wiki/Amoeba | Biology and health sciences | Other organisms: General | Plants |
TikTok, known in mainland China and Hong Kong as Douyin (), is a short-form video-hosting service owned by Chinese internet company ByteDance. It hosts user-submitted videos, which may range in duration from three seconds to 60 minutes. It can be accessed both through a mobile app or through its website.
Since its lau... | TikTok | Wikipedia | 480 | 56822861 | https://en.wikipedia.org/wiki/TikTok | Technology | Social network and blogging | null |
While TikTok and Douyin share a similar user interface, the platforms operate separately. Douyin includes an in-video search feature that can search by people's faces for more videos of them, along with other features such as buying, booking hotels, and making geo-tagged reviews.
TikTok
ByteDance planned on Douyin ex... | TikTok | Wikipedia | 512 | 56822861 | https://en.wikipedia.org/wiki/TikTok | Technology | Social network and blogging | null |
In May 2021, TikTok appointed Shou Zi Chew as their new CEO who assumed the position from interim CEO Vanessa Pappas, following the resignation of Kevin A. Mayer on 27 August 2020. In September 2021, TikTok reported that it had reached 1 billion users. In 2021, TikTok earned $4 billion in advertising revenue.
In Octob... | TikTok | Wikipedia | 377 | 56822861 | https://en.wikipedia.org/wiki/TikTok | Technology | Social network and blogging | null |
In January 2025, Chinese officials began preliminary talks about potentially selling TikTok's U.S. operations to Elon Musk if the app faced an impending ban due to national security concerns. While Beijing preferred TikTok remain under ByteDance's control, the sale could happen through a competitive process or with U.S... | TikTok | Wikipedia | 471 | 56822861 | https://en.wikipedia.org/wiki/TikTok | Technology | Social network and blogging | null |
The advertising revenue of short video clips is lower than other social media: while users spend more time, American audience is monetized at a rate of $0.31 per hour, a third the rate of Facebook and a fifth the rate of Instagram, $67 per year while Instagram will make more than $200. In July 2023, Iranian Mehr News A... | TikTok | Wikipedia | 362 | 56822861 | https://en.wikipedia.org/wiki/TikTok | Technology | Social network and blogging | null |
In March 2022, The Washington Post reported that Facebook's owner Meta Platforms paid Targeted Victory—a consulting firm backed by supporters of the U.S. Republican Party—to coordinate lobbying and media campaigns against TikTok and portray it as "a danger to American children and society". Its efforts included asking ... | TikTok | Wikipedia | 224 | 56822861 | https://en.wikipedia.org/wiki/TikTok | Technology | Social network and blogging | null |
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