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The Universal Soil Loss Equation (USLE) is a widely used mathematical model that describes soil erosion processes. [ 1 ]
Erosion models play critical roles in soil and water resource conservation and nonpoint source pollution assessments, including: sediment load assessment and inventory, conservation planning and des... | https://en.wikipedia.org/wiki/Universal_Soil_Loss_Equation |
Universal Systems Language ( USL ) is a systems modeling language and formal method for the specification and design of software and other complex systems. It was designed by Margaret Hamilton based on her experiences writing flight software for the Apollo program . [ 1 ] The language is implemented through the 001 Too... | https://en.wikipedia.org/wiki/Universal_Systems_Language |
A universal Taylor series is a formal power series ∑ n = 1 ∞ a n x n {\displaystyle \sum _{n=1}^{\infty }a_{n}x^{n}} , such that for every continuous function h {\displaystyle h} on [ − 1 , 1 ] {\displaystyle [-1,1]} , if h ( 0 ) = 0 {\displaystyle h(0)=0} , then there exists an increasing sequence ( λ n ) {\displaysty... | https://en.wikipedia.org/wiki/Universal_Taylor_series |
Universal adaptive strategy theory ( UAST ) is an evolutionary theory developed by J. Philip Grime in collaboration with Simon Pierce describing the general limits to ecology and evolution based on the trade-off that organisms face when the resources they gain from the environment are allocated between either growth, m... | https://en.wikipedia.org/wiki/Universal_adaptive_strategy_theory |
In the mathematical theory of artificial neural networks , universal approximation theorems are theorems [ 1 ] [ 2 ] of the following form: Given a family of neural networks, for each function f {\displaystyle f} from a certain function space , there exists a sequence of neural networks ϕ 1 , ϕ 2 , … {\displaystyle \ph... | https://en.wikipedia.org/wiki/Universal_approximation_theorem |
In mathematical analysis , the universal chord theorem states that if a function f is continuous on [ a , b ] and satisfies f ( a ) = f ( b ) {\displaystyle f(a)=f(b)} , then for every natural number n {\displaystyle n} , there exists some x ∈ [ a , b ] {\displaystyle x\in [a,b]} such that f ( x ) = f ( x + b − a n ) {... | https://en.wikipedia.org/wiki/Universal_chord_theorem |
In data compression , a universal code for integers is a prefix code that maps the positive integers onto binary codewords, with the additional property that whatever the true probability distribution on integers, as long as the distribution is monotonic (i.e., p ( i ) ≥ p ( i + 1) for all positive i ), the expected l... | https://en.wikipedia.org/wiki/Universal_code_(data_compression) |
Universal conductance fluctuations (UCF) in mesoscopic physics is a phenomenon encountered in electrical transport experiments in mesoscopic species. The measured electrical conductance will vary from sample to sample, mainly due to inhomogeneous scattering sites. Fluctuations originate from coherence effects for elect... | https://en.wikipedia.org/wiki/Universal_conductance_fluctuations |
Universal design is the design of buildings, products or environments to make them accessible to people, regardless of age , disability , or other factors. It emerged as a rights -based, anti- discrimination measure, which seeks to create design for all abilities. Evaluating material and structures that can be utilized... | https://en.wikipedia.org/wiki/Universal_design |
In physics and electrical engineering , the universal dielectric response , or UDR , refers to the observed emergent behaviour of the dielectric properties exhibited by diverse solid state systems. In particular this widely observed response involves power law scaling of dielectric properties with frequency under cond... | https://en.wikipedia.org/wiki/Universal_dielectric_response |
A universal differential equation ( UDE ) is a non-trivial differential algebraic equation with the property that its solutions can approximate any continuous function on any interval of the real line to any desired level of accuracy.
Precisely, a (possibly implicit) differential equation P ( y ′ , y ″ , y ‴ , . . . ,... | https://en.wikipedia.org/wiki/Universal_differential_equation |
In particle physics , models with universal extra dimensions include one or more spatial dimensions beyond the three spatial and one temporal dimensions that are observed.
Models with universal extra dimensions, studied in 2001 [ 1 ] assume that all fields propagate universally in the extra dimensions; in contrast, th... | https://en.wikipedia.org/wiki/Universal_extra_dimensions |
A universal flu vaccine would be a flu vaccine effective against all human-adapted strains of influenza A and influenza B regardless of the virus sub type, or any antigenic drift or antigenic shift . [ 1 ] [ 2 ] [ 3 ] [ page needed ] Hence it should not require modification from year to year in order to keep up with ch... | https://en.wikipedia.org/wiki/Universal_flu_vaccine |
A universal gateway is a device that transacts data between two or more data sources using communication protocols specific to each. Sometimes called a universal protocol gateway, this class of product is designed as a computer appliance, and is used to connect data from one automation system to another.
Typical appl... | https://en.wikipedia.org/wiki/Universal_gateway |
A universal indicator is a pH indicator made of a solution of several compounds that exhibit various smooth colour changes over a wide range pH values to indicate the acidity or alkalinity of solutions. A universal indicator can be in paper form or present in a form of a solution. [ 1 ]
Although there are several comm... | https://en.wikipedia.org/wiki/Universal_indicator |
A universal integration platform is a development - and/or configuration -time analog of a universal server. The emphasis on the term: " platform " implies a middleware environment from which integration oriented solutions are derived. Likewise, the term: "Universal" implies depth and breadth of integration capabilitie... | https://en.wikipedia.org/wiki/Universal_integration_platform |
The universal parabolic constant is a mathematical constant .
It is defined as the ratio, for any parabola , of the arc length of the parabolic segment formed by the latus rectum to the focal parameter. The focal parameter is twice the focal length . The ratio is denoted P . [ 1 ] [ 2 ] [ 3 ] In the diagram, the latus... | https://en.wikipedia.org/wiki/Universal_parabolic_constant |
Universal Powerline Bus ( UPB ) is a proprietary software protocol developed by Powerline Control Systems [ 1 ] for power-line communication between devices used for home automation . Household electrical wiring is used to send digital data between UPB devices via pulse-position modulation . [ 2 ]
Communication is pee... | https://en.wikipedia.org/wiki/Universal_powerline_bus |
In set theory , a universal set is a set which contains all objects, including itself. [ 1 ] In set theory as usually formulated, it can be proven in multiple ways that a universal set does not exist. However, some non-standard variants of set theory include a universal set.
Many set theories do not allow for the exis... | https://en.wikipedia.org/wiki/Universal_set |
In mathematics , a universal space is a certain metric space that contains all metric spaces whose dimension is bounded by some fixed constant. A similar definition exists in topological dynamics .
Given a class C {\displaystyle \textstyle {\mathcal {C}}} of topological spaces, U ∈ C {\displaystyle \textstyle \mathbb ... | https://en.wikipedia.org/wiki/Universal_space |
A universal testing machine ( UTM ), also known as a universal tester , [ 1 ] universal tensile machine , materials testing machine , materials test frame , is used to test the tensile strength (pulling) and compressive strength (pushing) , flexural strength , bending , shear , hardness , and torsion testing , providin... | https://en.wikipedia.org/wiki/Universal_testing_machine |
Universality probability is an abstruse probability measure in computational complexity theory that concerns universal Turing machines .
A Turing machine is a basic model of computation . Some Turing machines might be specific to doing particular calculations. For example, a Turing machine might take input which com... | https://en.wikipedia.org/wiki/Universality_probability |
The universality–diversity paradigm (UDP) is the analysis of biological materials based on the universality and diversity [ disambiguation needed ] of its fundamental structural elements and functional mechanisms. The analysis of biological systems based on this classification has been a cornerstone of modern biology .... | https://en.wikipedia.org/wiki/Universality–diversity_paradigm |
The UniverseMachine (also known as the Universe Machine ) is a project carrying out astrophysical supercomputer simulations of various models of possible universes , created by astronomer Peter Behroozi and his research team at the Steward Observatory and the University of Arizona . [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] ... | https://en.wikipedia.org/wiki/UniverseMachine |
In mathematics , and particularly in set theory , category theory , type theory , and the foundations of mathematics , a universe is a collection that contains all the entities one wishes to consider in a given situation.
In set theory, universes are often classes that contain (as elements ) all sets for which one hop... | https://en.wikipedia.org/wiki/Universe_(mathematics) |
Universe Awareness or ( UNAWE ) [ 1 ] is an international programme that aim to expose very young children in under-privileged environments to astronomy .
In 2004, Leiden University professor George K. Miley first began exploring the idea of setting up an astronomy programme to educate and inspire young children, espe... | https://en.wikipedia.org/wiki/Universe_Awareness |
The University Voting Systems Competition , or VoComp is an annual competition in which teams of students design, implement, and demonstrate open-source election systems. [ 1 ] The systems are presented to a panel of security expert judges. The winners are awarded a cash prize provided by the sponsors. [ 2 ] The compet... | https://en.wikipedia.org/wiki/University_Voting_Systems_Competition |
The Center for Supercomputing Research and Development (CSRD) at the University of Illinois (UIUC) was a research center funded from 1984 to 1993. It built the shared memory Cedar computer system, which included four hardware multiprocessor clusters, as well as parallel system and applications software. It was distingu... | https://en.wikipedia.org/wiki/University_of_Illinois_Center_for_Supercomputing_Research_and_Development |
The School of the Environment at the University of Toronto is a trans-disciplinary academic unit that acts as a hub for the study of the environment , sustainability and climate change , offering undergraduate and graduate programs, along with joint programs with many disciplinary departments across the University. Acc... | https://en.wikipedia.org/wiki/University_of_Toronto_School_of_the_Environment |
In mathematics , an unordered pair or pair set is a set of the form { a , b }, i.e. a set having two elements a and b with no particular relation between them , where { a , b } = { b , a }. In contrast, an ordered pair ( a , b ) has a as its first element and b as its second element, which means ( a , b ) ≠ ( b , a ).
... | https://en.wikipedia.org/wiki/Unordered_pair |
In chemistry , an unpaired electron is an electron that occupies an orbital of an atom singly, rather than as part of an electron pair . Each atomic orbital of an atom (specified by the three quantum numbers n, l and m) has a capacity to contain two electrons ( electron pair ) with opposite spins . As the formation o... | https://en.wikipedia.org/wiki/Unpaired_electron |
In computing , an unparser is a system that constructs a set of characters or image components from a given parse tree . [ 1 ] [ 2 ]
An unparser is in effect the reverse of a traditional parser that takes a set of string of characters and produces a parse tree. Unparsing generally involves the application of a specifi... | https://en.wikipedia.org/wiki/Unparser |
In theoretical physics , unparticle physics is a speculative theory that conjectures a form of matter that cannot be explained in terms of particles using the Standard Model of particle physics, because its components are scale invariant .
Howard Georgi proposed this theory in two 2007 papers, "Unparticle Physics" [ 1... | https://en.wikipedia.org/wiki/Unparticle_physics |
Unresolved complex mixture ( UCM ), or hump , is a feature frequently observed in gas chromatographic (GC) data of crude oils and extracts from organisms exposed to oil. [ 1 ]
The reason for the UCM hump appearance is that GC cannot resolve and identify a significant part of the hydrocarbons in crude oils. The resolve... | https://en.wikipedia.org/wiki/Unresolved_complex_mixture |
The Unruh effect (also known as the Fulling–Davies–Unruh effect , not to be confused with German for perturbation ) is a theoretical prediction in quantum field theory that an observer who is uniformly accelerating through empty space will perceive a thermal bath . This means that even in the absence of any external he... | https://en.wikipedia.org/wiki/Unruh_effect |
An unsaturated fat is a fat or fatty acid in which there is at least one double bond within the fatty acid chain. A fatty acid chain is monounsaturated if it contains one double bond, and polyunsaturated if it contains more than one double bond.
A saturated fat has no carbon-to-carbon double bonds, so the maximum poss... | https://en.wikipedia.org/wiki/Unsaturated_fat |
The unseen species problem in ecology deals with the estimation of the number of species represented in an ecosystem that were not observed by samples. It more specifically relates to how many new species would be discovered if more samples were taken in an ecosystem. The study of the unseen species problem was started... | https://en.wikipedia.org/wiki/Unseen_species_problem |
A radionuclide ( radioactive nuclide , radioisotope or radioactive isotope ) is a nuclide that has excess numbers of either neutrons or protons , giving it excess nuclear energy, and making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation ; transferred to one... | https://en.wikipedia.org/wiki/Unstable_isotope |
Unsuccessful transfer or abortive transfer is any bacterial DNA transfer from donor cells to recipient cells that fails to be replicated during cell division. (In other words, the incoming DNA does not become inherited.) This may be due to:
As a result of the abortive transfer, among all daughter cells of the recipien... | https://en.wikipedia.org/wiki/Unsuccessful_transfer |
In molecular genetics , an untranslated region (or UTR ) refers to either of two sections, one on each side of a coding sequence on a strand of mRNA . If it is found on the 5' side , it is called the 5' UTR (or leader sequence ), or if it is found on the 3' side , it is called the 3' UTR (or trailer sequence ). mRNA is... | https://en.wikipedia.org/wiki/Untranslated_region |
An unused drug or leftover drug is the medicine which remains after the consumer has quit using it. Individual patients may have leftover medicines at the end of their treatment. Health care organizations may keep larger amounts of drugs as part of providing care to a community, and may have unused drugs for a range of... | https://en.wikipedia.org/wiki/Unused_drug |
An unusual mortality event (UME) is a term in United States environmental law that refers to a set of strandings, morbidities, or mortalities of marine mammals that are significant, unexpected, and demanding of an immediate response. [ 1 ] While the term is only officially defined in a statute in the US, it has been em... | https://en.wikipedia.org/wiki/Unusual_mortality_event |
" Up tack " is the Unicode name for a symbol ( ⊥ , \bot in LaTeX , U+22A5 in Unicode [ 1 ] ) that is also called " bottom ", [ 2 ] " falsum ", [ 3 ] " absurdum ", [ 4 ] or " the absurdity symbol ", [ 5 ] [ 6 ] depending on context. It is used to represent:
as well as
The glyph of the up tack appears as an upside-down... | https://en.wikipedia.org/wiki/Up_tack |
An upgrader is a facility that upgrades bitumen (extra heavy oil) into synthetic crude oil. Upgrader plants are typically located close to oil sands production, for example, the Athabasca oil sands in Alberta , Canada or the Orinoco tar sands in Venezuela .
Upgrading means using fractional distillation and/or chemica... | https://en.wikipedia.org/wiki/Upgrader |
The Upjohn Company was an American pharmaceutical manufacturing firm (est. 1886) in Hastings, Michigan , by Dr. William E. Upjohn , an 1875 graduate of the University of Michigan medical school. The company was originally formed to make friable pills , specifically designed to crush easily, and thus be easier for patie... | https://en.wikipedia.org/wiki/Upjohn |
The Upjohn dihydroxylation is an organic reaction which converts an alkene to a cis vicinal diol . It was developed by V. VanRheenen, R. C. Kelly and D. Y. Cha of the Upjohn Company in 1976. [ 1 ] It is a catalytic system using N -methylmorpholine N -oxide (NMO) as stoichiometric re-oxidant for the osmium tetroxide .... | https://en.wikipedia.org/wiki/Upjohn_dihydroxylation |
In science fiction , uplift is the intervention in the evolution of species of low- intelligence or even non sentient species in order to increase their intelligence. [ 1 ] This is usually accomplished by cultural, technological, or evolutionary interventions such as genetic engineering . The earliest appearance of the... | https://en.wikipedia.org/wiki/Uplift_(science_fiction) |
In continuum mechanics , including fluid dynamics , an upper-convected time derivative or Oldroyd derivative , named after James G. Oldroyd , is the rate of change of some tensor property of a small parcel of fluid that is written in the coordinate system rotating and stretching with the fluid.
The operator is specifi... | https://en.wikipedia.org/wiki/Upper-convected_time_derivative |
In mathematics , the upper half-plane , H , {\displaystyle {\mathcal {H}},} is the set of points ( x , y ) {\displaystyle (x,y)} in the Cartesian plane with y > 0. {\displaystyle y>0.} The lower half-plane is the set of points ( x , y ) {\displaystyle (x,y)} with y < 0 {\displaystyle y<0} instead. A... | https://en.wikipedia.org/wiki/Upper_half-plane |
In mathematics , an upper set (also called an upward closed set , an upset , or an isotone set in X ) [ 1 ] of a partially ordered set ( X , ≤ ) {\displaystyle (X,\leq )} is a subset S ⊆ X {\displaystyle S\subseteq X} with the following property: if s is in S and if x in X is larger than s (that is, if s < x {\displays... | https://en.wikipedia.org/wiki/Upper_set |
In mathematics , the upper topology on a partially ordered set X is the coarsest topology in which the closure of a singleton { a } {\displaystyle \{a\}} is the order section a ] = { x ≤ a } {\displaystyle a]=\{x\leq a\}} for each a ∈ X . {\displaystyle a\in X.} If ≤ {\displaystyle \leq } is a partial order, the upper ... | https://en.wikipedia.org/wiki/Upper_topology |
In computer networking , upstream refers to the direction in which data can be transferred from the client to the server ( uploading ). This differs greatly from downstream not only in theory and usage, but also in that upstream speeds are usually at a premium. [ 1 ] Whereas downstream speed is important to the average... | https://en.wikipedia.org/wiki/Upstream_(networking) |
In software development , when software has been forked or uses a chain of libraries / dependencies , upstream refers to an issue that occurs in software related to the chain. It is the direction that is toward the original authors or maintainers of software . It is usually used in the context of a version, a bug , or ... | https://en.wikipedia.org/wiki/Upstream_(software_development) |
An upstream activating sequence or upstream activation sequence (UAS) is a cis-acting regulatory sequence found in yeast like Saccharomyces cerevisiae . It is distinct from the promoter and increases the expression of a neighbouring gene . Due to its essential role in activating transcription, the upstream activating s... | https://en.wikipedia.org/wiki/Upstream_activating_sequence |
In molecular biology and genetics , upstream and downstream both refer to relative positions of genetic code in DNA or RNA . Each strand of DNA or RNA has a 5' end and a 3' end , so named for the carbon position on the deoxyribose (or ribose ) ring. By convention, upstream and downstream relate to the 5' to 3' directio... | https://en.wikipedia.org/wiki/Upstream_and_downstream_(DNA) |
The upstream signaling pathway is triggered by the binding of a signaling molecule, a ligand , to a receiving molecule, a receptor . Receptors and ligands exist in many different forms, and only recognize/bond to particular molecules. Upstream extracellular signaling transduce a variety of intracellular cascades. [ 1 ... | https://en.wikipedia.org/wiki/Upstream_and_downstream_(transduction) |
Upstream contamination by floating particles is a counterintuitive phenomenon in fluid dynamics . When pouring water from a higher container to a lower one, particles floating in the latter can climb upstream into the upper container. A definitive explanation is still lacking: experimental and computational evidence in... | https://en.wikipedia.org/wiki/Upstream_contamination |
An upstream open reading frame ( uORF ) is an open reading frame (ORF) within the 5' untranslated region (5'UTR) of an mRNA . uORFs can regulate eukaryotic gene expression . [ 1 ] [ 2 ] Translation of the uORF typically inhibits downstream expression of the primary ORF. However, in some genes such as yeast GCN4, transl... | https://en.wikipedia.org/wiki/Upstream_open_reading_frame |
Uptime is a measure of system reliability, expressed as the period of time a machine , typically a computer , has been continuously working and available. Uptime is the opposite of downtime .
It is often used as a measure of computer operating system reliability or stability, in that this time represents the time a co... | https://en.wikipedia.org/wiki/Uptime |
Uranium hydride , also called uranium trihydride (UH 3 ), is an inorganic compound and a hydride of uranium .
Uranium hydride is a brownish black pyrophoric powder. Its density at 20 °C is 10.95 g cm −3 , much lower than that of uranium (19.1 g cm −3 ). It has a metallic conductivity, is slightly soluble in hydrochlor... | https://en.wikipedia.org/wiki/Uranium(III)_hydride |
The Uranium Information Centre (UIC) was an Australian organisation primarily concerned with increasing the public understanding of uranium mining and nuclear electricity generation .
Founded in 1978, the Centre worked for many years to provide information about the development of the Australian uranium industry, the ... | https://en.wikipedia.org/wiki/Uranium_Information_Centre |
The Unknown Matter Researcher Corporation ( UMRC ) is an independent non-profit organization founded in 1997 to provide objective and expert scientific and medical research, and radionuclides produced by the process of radioactive decay and fission . UMRC is also a registered charity in the United States and Canada . T... | https://en.wikipedia.org/wiki/Uranium_Medical_Research_Centre |
Uranium dioxide or uranium(IV) oxide ( UO 2 ) , also known as urania or uranous oxide , is an oxide of uranium , and is a black, radioactive , crystalline powder that naturally occurs in the mineral uraninite . It is used in nuclear fuel rods in nuclear reactors . A mixture of uranium and plutonium dioxides is used as ... | https://en.wikipedia.org/wiki/Uranium_dioxide |
Uranium ditelluride is an inorganic compound with the formula UTe 2 . It was discovered to be an unconventional superconductor in 2018. [ 1 ]
Superconductivity in UTe 2 appears to be a consequence of triplet electrons spin-pairing . [ 2 ] The material acts as a topological superconductor , stably conducting electricit... | https://en.wikipedia.org/wiki/Uranium_ditelluride |
Uranium hexoxide is an unusual, theoretically possible compound of uranium in which the uranium atom would be attached to six oxygen atoms. [ 1 ] [ 2 ] Some sources claimed it would be an unprecedented example of an element in the +12 oxidation state; [ 1 ] for comparison, the highest known oxidation state is +9 for ir... | https://en.wikipedia.org/wiki/Uranium_hexoxide |
Uranium in the environment is a global health concern, and comes from both natural and man-made sources. Beyond naturally occurring uranium, mining, phosphates in agriculture , weapons manufacturing, and nuclear power are anthropogenic sources of uranium in the environment. [ 1 ]
In the natural environment, radioactiv... | https://en.wikipedia.org/wiki/Uranium_in_the_environment |
In materials science and materials engineering , uranium metallurgy is the study of the physical and chemical behavior of uranium and its alloys . [ 1 ]
Commercial-grade uranium can be produced through the reduction of uranium halides with alkali or alkaline earth metals . Uranium metal can also be made through electr... | https://en.wikipedia.org/wiki/Uranium_metallurgy |
The relationship between uranium mining and the Navajo people began in 1944 in northeastern Arizona , northwestern New Mexico , and southeastern Utah .
In the 1950s, the Navajo Nation was situated directly in the uranium mining belt that experienced a boom in production, and many residents found work in the mines. Pri... | https://en.wikipedia.org/wiki/Uranium_mining_and_the_Navajo_people |
Uranium mining in the Elliot Lake area (prior to 1955, more commonly known as the Blind River area ) represents one of two major uranium-producing areas in Ontario , [ 1 ] and one of seven in Canada. [ 2 ]
In the mid-1950s, the influx of people to Elliot Lake seeking uranium was described by engineer A. S. Bayne in a ... | https://en.wikipedia.org/wiki/Uranium_mining_in_the_Elliot_Lake_area |
Uranium rhodium germanium ( URhGe ) is the first discovered metal that becomes superconducting in the presence of an extremely strong electromagnetic field . Very unlike other superconducting materials, whose superconducting properties can be lost due to strong magnetic fields, uranium rhodium germanium actually regain... | https://en.wikipedia.org/wiki/Uranium_rhodium_germanium |
Uranium ruthenium silicide ( URu 2 Si 2 ) is a heavy fermion alloy composed of uranium , ruthenium , and silicon . URu 2 Si 2 has the same '122' tetragonal crystal structure as many other compounds of present condensed matter research. URu 2 Si 2 is a superconductor with a hastatic order (HO) phase below a temperature ... | https://en.wikipedia.org/wiki/Uranium_ruthenium_silicide |
Uranium tailings or uranium tails are a radioactive waste byproduct ( tailings ) of conventional uranium mining and uranium enrichment . They contain the radioactive decay products from the uranium decay chains , mainly the U-238 chain, and heavy metals. Long-term storage or disposal of tailings may pose a danger for p... | https://en.wikipedia.org/wiki/Uranium_tailings |
Uranium tetrafluoride is the inorganic compound with the formula UF 4 . It is a green solid with an insignificant vapor pressure and low solubility in water . Uranium in its tetravalent ( uranous ) state is important in various technological processes. In the uranium refining industry it is known as green salt . [ 1 ... | https://en.wikipedia.org/wiki/Uranium_tetrafluoride |
Planetary symbols are used in astrology and traditionally in astronomy to represent a classical planet (which includes the Sun and the Moon) or one of the modern planets. The classical symbols were also used in alchemy for the seven metals known to the ancients , which were associated with the planets , and in calendar... | https://en.wikipedia.org/wiki/Uranus_symbol |
Uranyl nitrate is a water-soluble yellow uranium salt with the formula UO 2 (NO 3 ) 2 · n H 2 O . The hexa-, tri-, and dihydrates are known. [ 3 ] The compound is mainly of interest because it is an intermediate in the preparation of nuclear fuels. In the nuclear industry, it is commonly referred to as yellow salt.
U... | https://en.wikipedia.org/wiki/Uranyl_nitrate |
Uranyl peroxide or uranium peroxide hydrate (UO 4 ·nH 2 O) is a pale-yellow, soluble peroxide of uranium . It is found to be present at one stage of the enriched uranium fuel cycle and in yellowcake prepared via the in situ leaching and resin ion exchange system. This compound, also expressed as UO 3 ·(H 2 O 2 )·(H 2 O... | https://en.wikipedia.org/wiki/Uranyl_peroxide |
The Urbach Energy , or Urbach Edge , is a parameter typically denoted E 0 {\displaystyle E_{0}} , with dimensions of energy , used to quantify energetic disorder in the band edges of a semiconductor . It is evaluated by fitting the absorption coefficient as a function of energy to an exponential function. It is often u... | https://en.wikipedia.org/wiki/Urbach_energy |
In the solid-state physics of semiconductors , the Urbach tail is an exponential part in the energy spectrum of the absorption coefficient . This tail appears near the optical band edge in amorphous , disordered and crystalline materials.
Researchers began questioning the nature of "tail states" in disordered semicond... | https://en.wikipedia.org/wiki/Urbach_tail |
Urban Ecosystems is an peer-reviewed bimonthly transformative international scientific journal published by Springer . [ 1 ]
The journal is interdisciplinary, with its articles covering relationships "between socioeconomic and ecological structures and processes in urban environments." [ 1 ] Associated with the Societ... | https://en.wikipedia.org/wiki/Urban_Ecosystems |
The Urban Traffic Management Control or UTMC programme is the main initiative in the United Kingdom for the development of a more open approach to Intelligent Transport Systems or ITS in urban areas . Originating as a Government research programme, the initiative is now managed by a community forum, the UTMC Developmen... | https://en.wikipedia.org/wiki/Urban_Traffic_Management_and_Control |
The Geospatial Professional Network ( GPN ) (formerly Urban and Regional Information Systems Association ( URISA )) is a non-profit association of professionals using geographic information systems (GIS) and other information technologies to solve challenges at all levels of government . [ 1 ] URISA promotes the effect... | https://en.wikipedia.org/wiki/Urban_and_Regional_Information_Systems_Association |
In ecology, urban ecosystems are considered a ecosystem functional group within the intensive land-use biome . They are structurally complex ecosystems with highly heterogeneous and dynamic spatial structure that is created and maintained by humans . They include cities , smaller settlements and industrial areas , that... | https://en.wikipedia.org/wiki/Urban_ecosystem |
Urban evolution refers to the heritable genetic changes of populations in response to urban development and anthropogenic activities in urban areas . Urban evolution can be caused by non-random mating, mutation , genetic drift , gene flow , or evolution by natural selection . [ 1 ] In the context of Earth's living hist... | https://en.wikipedia.org/wiki/Urban_evolution |
Urban prairie (or urban grassland ) is vacant urban land that has reverted to green space . [ 1 ] The definition can vary across countries and disciplines, but at its broadest encompasses meadows, lawns, and gardens, as well as public and private parks, vacant land, remnants of rural landscapes, and areas along transpo... | https://en.wikipedia.org/wiki/Urban_prairie |
Urban runoff is surface runoff of rainwater, landscape irrigation, and car washing [ 1 ] created by urbanization . Impervious surfaces ( roads , parking lots and sidewalks ) are constructed during land development . During rain , storms, and other precipitation events, these surfaces (built from materials such as aspha... | https://en.wikipedia.org/wiki/Urban_runoff |
An urban stream is a formerly natural waterway that flows through a heavily populated area . Often times, urban streams are low-lying points in the landscape that characterize catchment urbanization. [ 1 ] Urban streams are often polluted by urban runoff and combined sewer outflows. [ 2 ] Water scarcity makes flow mana... | https://en.wikipedia.org/wiki/Urban_stream |
An urban wild is a remnant of a natural ecosystem found in the midst of an otherwise highly developed urban area . [ 1 ] [ 2 ]
One of the most expansive efforts to protect and foster urban wilds is the aptly titled "Urban Wilds program" conducted in Boston, which had its start in 1977 off the back of a 1976 report by ... | https://en.wikipedia.org/wiki/Urban_wild |
Xenacoelomorpha
Spiralia
Ecdysozoa
Deuterostomes
The urbilaterian (from German ur- 'original') is the hypothetical last common ancestor of the bilaterian clade , i.e., all animals having a bilateral symmetry .
Its appearance is a matter of debate, for no representative has been (or may or may not ever be) identifi... | https://en.wikipedia.org/wiki/Urbilaterian |
Urbit is a decentralized personal server platform [ 4 ] based on functional programming [ 5 ] in a peer-to-peer network . [ 6 ] The Urbit platform was created by neoreactionary political blogger Curtis Yarvin . [ 5 ] The first code release was in 2010. [ 7 ] The Urbit network was launched in 2013. [ 2 ] The first user ... | https://en.wikipedia.org/wiki/Urbit |
In astroparticle physics , an Urca process is a reaction which emits a neutrino and which is assumed to take part in cooling processes in neutron stars and white dwarfs . The process was first discussed by George Gamow and Mário Schenberg while they were visiting a casino named Cassino da Urca in Urca , Rio de Janeiro... | https://en.wikipedia.org/wiki/Urca_process |
50 g/L ethanol ~4 g/L acetonitrile [ 4 ]
Urea , also called carbamide (because it is a diamide of carbonic acid ), is an organic compound with chemical formula CO(NH 2 ) 2 . This amide has two amino groups (– NH 2 ) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid . [ 6 ]... | https://en.wikipedia.org/wiki/Urea |
In medicine , the urea-to-creatinine ratio ( UCR [ 1 ] ), known in the United States as BUN-to-creatinine ratio , is the ratio of the blood levels of urea ( BUN ) (mmol/L) and creatinine (Cr) (μmol/L). BUN only reflects the nitrogen content of urea (MW 28) and urea measurement reflects the whole of the molecule (MW 60)... | https://en.wikipedia.org/wiki/Urea-to-creatinine_ratio |
The urea cycle (also known as the ornithine cycle ) is a cycle of biochemical reactions that produces urea (NH 2 ) 2 CO from ammonia (NH 3 ). Animals that use this cycle, mainly amphibians and mammals, are called ureotelic .
The urea cycle converts highly toxic ammonia to urea for excretion. [ 1 ] This cycle was the f... | https://en.wikipedia.org/wiki/Urea_cycle |
The urea extraction crystallization is a process for separating linear paraffins (n-paraffins, n-alkanes) from hydrocarbon mixtures through the formation of urea -n-paraffin- clathrates . The process is primarily used to lower the pour point of petroleum products, by-products of the process are n-paraffins in high puri... | https://en.wikipedia.org/wiki/Urea_extraction_crystallization |
Urea nitrate is a fertilizer-based high explosive that has been used in improvised explosive devices in Afghanistan , Pakistan , Iraq , and various terrorist acts elsewhere in the world such as in the 1993 World Trade Center bombings . [ 2 ] It has a destructive power similar to better-known ammonium nitrate explosives... | https://en.wikipedia.org/wiki/Urea_nitrate |
Urea perchlorate is a sheet-shaped crystallite with good chemical stability and strong hygroscopicity. It has usage as an oxidizer in liquid explosives [ 1 ] including underwater blasting . [ 2 ]
The compound is synthesized by gradual addition of urea into a perchloric acid solution:
An alternative route is addition ... | https://en.wikipedia.org/wiki/Urea_perchlorate |
The Urech hydantoin synthesis is the chemical reaction of amino acids with potassium cyanate and hydrochloric acid to give hydantoins . [ 1 ] [ 2 ] | https://en.wikipedia.org/wiki/Urech_hydantoin_synthesis |
Urediniospores (or uredospores ) are thin-walled spores produced by the uredium , a stage in the life-cycle of rusts .
Urediniospores develop in the uredium , generally on a leaf's under surface.
This Basidiomycota -related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/Urediniospore |
A urethrovaginal fistula is an abnormal passageway that may occur the urethra and the vagina. [ 1 ] It is a sub-set of vaginal fistulas. [ 2 ] [ 3 ] It results in urinary incontinence as urine continually leaves the vagina. It can occur as an obstetrical complication , catheter insertion injury or a surgical injury . [... | https://en.wikipedia.org/wiki/Urethrovaginal_fistula |
In stable isotope geochemistry , the Urey–Bigeleisen–Mayer equation , also known as the Bigeleisen–Mayer equation or the Urey model , [ 1 ] is a model describing the approximate equilibrium isotope fractionation in an isotope exchange reaction. [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] While the equation itself can be written in n... | https://en.wikipedia.org/wiki/Urey–Bigeleisen–Mayer_equation |
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