text stringlengths 11 320k | source stringlengths 26 161 |
|---|---|
Uranyl fluoride is the inorganic compound with the formula UO 2 F 2 . It is most notable as a contaminant in the production of uranium tetrafluoride . [ 2 ]
As shown by X-ray crystallography , the uranyl centers UO 2+ 2 are surrounded by six fluoride ligands F − . [ 3 ]
This salt is very soluble in water as well as h... | https://en.wikipedia.org/wiki/UF2O2 |
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/UF4 |
Uranium pentafluoride is the inorganic compound with the chemical formula UF 5 . It is a pale yellow paramagnetic solid. The compound has attracted interest because it is related to uranium hexafluoride , which is widely used to produce uranium fuel. It crystallizes in two polymorphs , called α- and β-UF 5 .
Uranium... | https://en.wikipedia.org/wiki/UF5 |
Uranium hexafluoride , sometimes called hex , is the inorganic compound with the formula U F 6 . Uranium hexafluoride is a volatile, white solid that is used in enriching uranium for nuclear reactors and nuclear weapons . [ 4 ]
Uranium dioxide is converted with hydrofluoric acid (HF) to uranium tetrafluoride : [ 4 ]
... | https://en.wikipedia.org/wiki/UF6 |
Some conspiracy theories argue that various governments and politicians globally, in particular the United States government , are suppressing evidence that unidentified flying objects (UFO) are controlled by an extraterrestrial or "non-human" intelligence, or built using alien technology. [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ]... | https://en.wikipedia.org/wiki/UFO_conspiracy_theories |
Uranium hydride may refer to the following chemical compounds: | https://en.wikipedia.org/wiki/UH3 |
Uranium(IV) hydride is a chemical compound with the chemical formula U H 4 , a metal hydride .
In 1997, Souter et al. reported the production of UH 4 reacting laser ablated uranium atoms with di hydrogen and capturing the product on solid argon. The assignment of the structure was made using infrared spectroscopic evi... | https://en.wikipedia.org/wiki/UH4 |
Uranium triiodide is an inorganic compound with the chemical formula UI 3 . It is a black solid that is soluble in water.
Uranium triiodide can be obtained from the direct reaction of its constituent elements: [ 3 ]
When the reaction is conducted in tetrahydrofuran (THF), the product is the blue complex UI 3 (THF) 4... | https://en.wikipedia.org/wiki/UI3 |
Uranium(IV) iodide , also known as uranium tetraiodide , is an inorganic chemical compound . It is a salt of uranium in oxidation state +4 and iodine.
Uranium tetraiodide can be prepared from the reaction between uranium and an excess of iodine. [ 2 ]
Uranium tetraiodide is a black solid and forms needle-like crystal... | https://en.wikipedia.org/wiki/UI4 |
A UIMID (user identity module identifier) is a 32-bit Electronic Serial Number (ESN) stored in a R-UIM or CSIM ('smart card') used for TDMA or CDMA2000 phones (mainly the latter). It is given a different name to avoid confusion with the hardware ESN stored in the phone. In all known systems the UIMID displaces the ESN ... | https://en.wikipedia.org/wiki/UIMID |
The UKM Medical Molecular Biology Institute , usually referred to as UMBI, is a biomedicine and cancer research institute located in Bandar Tun Razak , Kuala Lumpur , Malaysia . The institute is one of research institute in National University of Malaysia (UKM). UMBI was established in 2003. [ 1 ] The institute has bee... | https://en.wikipedia.org/wiki/UKM_Medical_Molecular_Biology_Institute |
UKS 2323-326 is a very low mass and faint dwarf irregular galaxy located in the local group at a distance of 1.3 mpc from Earth . [ 2 ] The galaxy is a member of the Sculptor group . [ 3 ] The galaxy has a young stellar population that recently (~100 mya [ 3 ] ) formed defined red giant branch (RGB) stars but no signif... | https://en.wikipedia.org/wiki/UKS_2323-326 |
The UK Academy for Information Systems ( UKAIS ) is an active combination of a traditional learned society , communications channel and pressure group . It is a conduit for communication between industry and academia to ensure that relevant courses can be designed and research initiatives established throughout the UK ... | https://en.wikipedia.org/wiki/UK_Academy_for_Information_Systems |
The UK Battery Industrialisation Centre (UK BIC) is a research centre in the United Kingdom, to develop new electrical batteries , for the British automotive industry . UKBIC provides over £60 million worth of specialized manufacturing equipment, supporting manufacturers, entrepreneurs, researchers, and educators in ba... | https://en.wikipedia.org/wiki/UK_Battery_Industrialisation_Centre |
The UK Centre for Astrobiology was set up at the University of Edinburgh in 2011 [ 1 ] [ 2 ] by Charles Cockell . It was set up as a UK node, formally affiliated as an international partner with the NASA Astrobiology Institute (NAI) alongside other national nodes until the NAI's dissolution in 2019. It was established ... | https://en.wikipedia.org/wiki/UK_Centre_for_Astrobiology |
The UK Centre for Materials Education (UKCME) was one of 24 subject centres within the Higher Education Academy (HEA). It supported teaching and learning in Materials Science and related disciplines. The Centre was established in 2000 as part of the Learning and Teaching Support Network (LTSN), later subsumed within t... | https://en.wikipedia.org/wiki/UK_Centre_for_Materials_Education |
The UK Molecular R-Matrix codes are a set of software routines used to calculate the effects of collision of electrons with atoms and molecules. The R-matrix method is used in computational quantum mechanics to study scattering of positrons and electrons by atomic and molecular targets. The fundamental idea was origina... | https://en.wikipedia.org/wiki/UK_Molecular_R-matrix_Codes |
The UK Museum of Ordure ( UKMO ) was an online arts project initiated with the intention to explore the curatorial value of ordure , or human waste . It consisted of a website [ 1 ] which initially collected public submissions of ordure, as well as documenting various installations undertaken by the museum. It has sinc... | https://en.wikipedia.org/wiki/UK_Museum_of_Ordure |
The UK National Quantum Technologies Programme ( UKNQTP ) is a programme set up by the UK government [ 1 ] to translate academic work on quantum mechanics , and the effects of quantum superposition and quantum entanglement into new products and services. It brings UK physicists and engineers together with companies and... | https://en.wikipedia.org/wiki/UK_National_Quantum_Technologies_Programme |
In computing , UMA Acceleration Architecture (UXA) is the reimplementation of the EXA graphics acceleration architecture of the X.Org Server developed by Intel . Its major difference with EXA is the use of GEM , replacing Translation Table Maps . [ 1 ] In February 2009 it became clear that UXA would not be merged back ... | https://en.wikipedia.org/wiki/UMA_Acceleration_Architecture |
UMS/UHD/UHX is a forklift truck in the Tergo series from the Swedish manufacturer Atlet AB . It differs from traditional forklift truck design philosophy in that it is entirely designed around the operator. By letting the forklift truck adjust to the operator's skills and body structure the UMS/UHD/UHX is an example of... | https://en.wikipedia.org/wiki/UMS/UHD/UHX |
The UNECE Environmental Performance Review ( EPR ) (French: Examen des performances environnementales – EPE) is an assessment process to evaluate the progress made by individual countries in improving their environmental policies. The EPRs are carried out under the auspices of the Committee on Environmental Policy of t... | https://en.wikipedia.org/wiki/UNECE_Environmental_Performance_Reviews |
The UNESCO Science Prize is a biennial scientific prize awarded by the United Nations Educational, Scientific and Cultural Organization (UNESCO) to "a person or group of persons for an outstanding contribution they have made to the technological development of a developing member state or region through the application... | https://en.wikipedia.org/wiki/UNESCO_Science_Prize |
uNETix is an early implementation of UNIX for IBM PC systems. It was not a "true" UNIX , but was written from scratch for the PC without using any code from System V .
uNETix only supported a single user. However, it maintained closer compatibility with standard versions of UNIX than early versions of QNX . uNETix' mu... | https://en.wikipedia.org/wiki/UNETix |
The UNIVAC 9000 series (9200, 9300, 9400, 9700) is a discontinued line of computers introduced by Sperry Rand in the mid-1960s to compete with the low end of the IBM System/360 series. The 9200 and 9300 (which differ only in CPU speed) implement the same restricted 16-bit subset of the System/360 instruction set as th... | https://en.wikipedia.org/wiki/UNIVAC_9000_series |
An explosive (or explosive material ) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light , heat , sound , and pressure . An explosive charge is a measured quantity of explosive material, which may ei... | https://en.wikipedia.org/wiki/UNO_Hazard_Class_and_Division |
The UN Recommendations on the Transport of Dangerous Goods are contained in the UN Model Regulations prepared by the Subcommittee of Experts on the Transport of Dangerous Goods of the United Nations Economic and Social Council (ECOSOC). They cover the transport of dangerous goods by all modes of transport except by bul... | https://en.wikipedia.org/wiki/UN_Recommendations_on_the_Transport_of_Dangerous_Goods |
The Report on the Alleged Use of Chemical Weapons in the Ghouta Area of Damascus on 21 August 2013 was a 2013 report produced by a team appointed by United Nations Secretary-General (UNSG) Ban Ki-moon to investigate alleged chemical weapon attacks during the Syrian civil war . [ 1 ] The report published on 16 September... | https://en.wikipedia.org/wiki/UN_investigation_of_chemical_weapons_use_in_Ghouta |
A UN number ( United Nations number) is a four-digit number that identifies hazardous materials , and articles (such as explosives , flammable liquids , oxidizers , toxic liquids, etc.) in the framework of international trade and transport . Some hazardous substances have their own UN numbers (e.g. acrylamide has UN 20... | https://en.wikipedia.org/wiki/UN_number |
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/UO2 |
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/UO2(NO3)2 |
Uranyl hydroxide is a hydroxide of uranium with the chemical formula UO 2 (OH) 2 in the monomeric form and [(UO 2 ) 2 (OH) 4 ] 2- in the dimeric; both forms may exist in normal aqueous media. In aerobic conditions, up to 5 hydroxides can bind to uranyl ([(UO 2 ) 2 (OH) 5 ] 3- ). Uranyl hydroxide hydrate is precipitate... | https://en.wikipedia.org/wiki/UO2(OH)2 |
Uranyl carbonate refers to the inorganic compound with the formula UO 2 CO 3 . Also known by its mineral name rutherfordine , this material consists of uranyl (UO 2 2+ ) and carbonate (CO 3 2- ). Like most uranyl salts, the compound is a polymeric, each uranium(VI) center being bonded to eight O atoms. [ 1 ] Hydrolysis... | https://en.wikipedia.org/wiki/UO2CO3 |
Uranyl chloride is a chemical compound with the chemical formula U O 2 Cl 2 . It consists of uranyl cations UO 2+ 2 and chloride anions Cl − . It is fluorescent . [ 1 ] Uranyl chloride also refers to inorganic compounds with the formula UO 2 Cl 2 (H 2 O) n where n = 0, 1, 2, or 3. These are yellow salts.
The hydrates ... | https://en.wikipedia.org/wiki/UO2Cl2 |
Uranyl fluoride is the inorganic compound with the formula UO 2 F 2 . It is most notable as a contaminant in the production of uranium tetrafluoride . [ 2 ]
As shown by X-ray crystallography , the uranyl centers UO 2+ 2 are surrounded by six fluoride ligands F − . [ 3 ]
This salt is very soluble in water as well as h... | https://en.wikipedia.org/wiki/UO2F2 |
Uranyl sulfate describes a family of inorganic compounds with the formula UO 2 SO 4 (H 2 O) n . These salts consist of sulfate , the uranyl ion , and water. They are lemon-yellow solids. Uranyl sulfates are intermediates in some extraction methods used for uranium ores. [ 1 ] These compounds can also take the form of a... | https://en.wikipedia.org/wiki/UO2SO4 |
Uranium trioxide (UO 3 ) , also called uranyl oxide , uranium(VI) oxide , and uranic oxide , is the hexavalent oxide of uranium . The solid may be obtained by heating uranyl nitrate to 400 °C. Its most commonly encountered polymorph is amorphous UO 3 .
There are three methods to generate uranium trioxide. As noted bel... | https://en.wikipedia.org/wiki/UO3 |
The UPRM College of Engineering is one of four colleges of the University of Puerto Rico at Mayaguez . This school is also the largest of its kind in Puerto Rico , with an enrollment of about 5,000 undergraduate students and about 400 graduates. It is the main producer of Hispanic engineers in the United States of Amer... | https://en.wikipedia.org/wiki/UPRM_College_of_Engineering |
The Department of Chemical Engineering (DChE) is an academic department operating under the College of Engineering of the University of the Philippines Diliman .
The department was established in 1956 and has an overall 90% passing rate in the licensure examinations held in the Philippines. It also contributes about 1... | https://en.wikipedia.org/wiki/UP_Diliman_Department_of_Chemical_Engineering |
UPd 2 Al 3 is a heavy-fermion superconductor with a hexagonal crystal structure and critical temperature T c =2.0K that was discovered in 1991. [ 1 ] Furthermore, UPd 2 Al 3 orders antiferromagnetically at T N =14K, and UPd 2 Al 3 thus features the unusual behavior that this material, at temperatures below 2K, is simul... | https://en.wikipedia.org/wiki/UPd2Al3 |
UPt 3 is an inorganic binary intermetallic crystalline compound of platinum and uranium . [ 1 ]
It can be synthesised in the following ways: [ 3 ]
UPt 3 forms crystals of hexagonal symmetry (some studies hypothesize a trigonal structure instead [ 4 ] ), space group P6 3 /mmc, [ 5 ] cell parameters a = 0.5766 nm and c... | https://en.wikipedia.org/wiki/UPt3 |
The U.S. Bureau of Mines (USBM) , developed by Donaldson et al. in 1969, is a method to measure wettability of petroleum reservoir rocks. In this method, the areas under the forced displacement Capillary pressure curves of oil and water drive processes are denoted as A 1 {\displaystyle A1} and A 2 {\displaystyle A2} t... | https://en.wikipedia.org/wiki/USBM_wettability_index |
A USB image — is bootable image of Operating system (OS) or other software where the boot loader is located on a USB flash drive , or another USB device (with memory storage) instead of conventional CD or DVD discs. The operating system loads from the USB device either to load it much like a Live CD that runs OS or any... | https://en.wikipedia.org/wiki/USB_image |
USP26 is a peptidase enzyme. The USP26 gene is an X-linked gene exclusively expressed in the testis and it codes for the ubiquitin-specific protease 26. [ 1 ] The USP26 gene is found at Xq26.2 on the X-chromosome as a single exon. The enzyme that this gene encodes comprises 913 amino acid residues and it is 104 kilodal... | https://en.wikipedia.org/wiki/USP26 |
The USP Controlled Room Temperature is a series of United States Pharmacopeia guidelines for the storage of pharmaceuticals; [ 1 ] the relevant omnibus standard is USP 797. [ 2 ] [ 3 ] Although 100% compliance remains challenging for any given facility, [ 4 ] the larger protocol may be regarded as constituting a form o... | https://en.wikipedia.org/wiki/USP_Controlled_Room_Temperature |
US Fleet Tracking is a privately owned company that specializes in manufacturing and distributing GPS Tracking products and accessories designed to enable businesses and individuals to monitor their mobile assets and vehicle fleets, tracking those vehicles live, in realtime, as they move.
The company manufactures a va... | https://en.wikipedia.org/wiki/US_Fleet_Tracking |
UTRdb 2.0 is an updated version of the specialized database UTRdb , which focuses on the 5' and 3' untranslated regions (UTRs) of eukaryotic mRNAs . These UTRs play essential roles in the post-transcriptional regulation of gene expression by influencing various processes, including nucleo-cytoplasmic mRNA transport, tr... | https://en.wikipedia.org/wiki/UTRdb |
UTRome is a database of three-prime untranslated regions in C. elegans [ 1 ] developed by Marco Mangone
This Biological database -related article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/UTRome |
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/UTe2 |
UV-328 ( 2-(2 H -benzotriazol-2-yl)-4,6-di- tert -pentylphenol ) is a chemical compound that belongs to the phenolic benzotriazoles . It is a UV filter that is used as an UV-absorber for plastics. [ 3 ]
UV-328 has a melting point of 80-86 °C, a vapor pressure of 4,6·10 −5 Pa (20 °C) and a water solubility of 0,17±0,07... | https://en.wikipedia.org/wiki/UV-328 |
Ultraviolet-visible (UV-Vis) absorption spectroelectrochemistry (SEC) is a multiresponse technique that analyzes the evolution of the absorption spectra in UV-Vis regions during an electrode process. [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] This technique provides information from an electrochemical and spectroscopic point ... | https://en.wikipedia.org/wiki/UV-Vis_absorption_spectroelectrochemistry |
UV-sensitive syndrome is a cutaneous condition inherited in an autosomal recessive fashion, characterized by photosensitivity and solar lentigines . [ 1 ] Recent research identified that mutations of the KIAA1530 (UVSSA) gene as cause for the development of UV-sensitive syndrome. [ 2 ] Furthermore, this protein was ide... | https://en.wikipedia.org/wiki/UV-sensitive_syndrome |
The Ultraviolet Explorer ( UVEX ) is an upcoming wide-field ultraviolet space telescope from NASA scheduled to launch in 2030. [ 1 ] UVEX will build off of previous ultraviolet space telescopes, specifically GALEX , conducting surveys of the entire sky in both near- and far-ultraviolet light. UVEX will study the evolut... | https://en.wikipedia.org/wiki/UVEX |
A UV coating (or more generally a radiation cured coating) is a surface treatment which either is cured by ultraviolet radiation, or which protects the underlying material from such radiation's harmful effects. [ 1 ] They have come to the fore because they are considered environmentally friendly and do not use solvents... | https://en.wikipedia.org/wiki/UV_coating |
UV curing ( ultraviolet curing ) is the process by which ultraviolet light initiates a photochemical reaction that generates a crosslinked network of polymers through radical polymerization or cationic polymerization . [ 1 ] UV curing is adaptable to printing , coating , decorating, stereolithography , and in the asse... | https://en.wikipedia.org/wiki/UV_curing |
An ultraviolet detector (also known as UV detector or UV-Vis detector ) [ 1 ] [ 2 ] is a type of non-destructive chromatography detector which measures the amount of ultraviolet or visible light absorbed by components of the mixture being eluted off the chromatography column. They are often used as detectors for high-p... | https://en.wikipedia.org/wiki/UV_detectors |
UV pinning is the process of applying a dose of low intensity ultraviolet (UV) light to a UV curable ink (UV ink). The light's wavelengths must be correctly matched to the ink's photochemical properties. As a result, the ink droplets move to a higher viscosity state, but stop short of full cure . This is also referr... | https://en.wikipedia.org/wiki/UV_pinning |
The UWA telerobot is a teleoperable robot belonging to the school of mechanical and civil engineering at the University of Western Australia .
The UWA telerobot is a historic landmark for the Internet and The University of Western Australia. It was the first telerobot device made available for general use on the Inter... | https://en.wikipedia.org/wiki/UWA_Telerobot |
Ubiquitin-AMC is a fluorogenic substrate for a wide range of deubiquitinating enzymes (DUBs), including ubiquitin C-terminal hydrolases (UCHs) and ubiquitin specific proteases (USPs). It is a particularly useful reagent for the study of deubiquitinating activity where detection sensitivity or continuous monitoring of a... | https://en.wikipedia.org/wiki/Ub-AMC |
An Ubbelohde type viscometer or suspended-level viscometer is a measuring instrument which uses a capillary based method of measuring viscosity . [ 2 ] [ 3 ] It is recommended for higher viscosity cellulosic polymer solutions. The advantage of this instrument is that the values obtained are independent of the total vol... | https://en.wikipedia.org/wiki/Ubbelohde_viscometer |
Ubenimex ( INN ), also known more commonly as bestatin , is a competitive, reversible protease inhibitor . It is an inhibitor of arginyl aminopeptidase (aminopeptidase B), [ 3 ] leukotriene A 4 hydrolase (a zinc metalloprotease that displays both epoxide hydrolase and aminopeptidase activities), [ 4 ] alanyl aminopepti... | https://en.wikipedia.org/wiki/Ubenimex |
The Ubersketch is a moniker for a collection of sketches created in The Geometer's Sketchpad by the PRISM-NEO project which mimic ( virtual ) manipulatives , such as the ones found at The National Library of Virtual Manipulatives. The editor of the collection is Greg Clarke of the Simcoe-Muskoka Catholic District Schoo... | https://en.wikipedia.org/wiki/Ubersketch |
Ubique was an Israeli software company that produced social-networking and messaging software. Founded in 1994, Ubique is notable for launching the first social-networking software, which included features such as instant messaging, voice over IP ( VoIP ), chat rooms, web-based events, and collaborative browsing.
The ... | https://en.wikipedia.org/wiki/Ubique_(company) |
Ubiquinol oxidases ( EC 1.10.3.11 ) are enzymes in the bacterial electron transport chain that oxidise ubiquinol into ubiquinone and reduce oxygen to water. These enzymes are one set of the many alternative terminal oxidases in the branched prokaryotic electron transport chain. [ 1 ] The overall structure of the E. col... | https://en.wikipedia.org/wiki/Ubiquinol_oxidase |
Ubiquitin-conjugating enzymes , also known as E2 enzymes and more rarely as ubiquitin-carrier enzymes , perform the second step in the ubiquitination reaction that targets a protein for degradation via the proteasome . The ubiquitination process covalently attaches ubiquitin , a short protein of 76 amino acids , to a l... | https://en.wikipedia.org/wiki/Ubiquitin-conjugating_enzyme |
Ubiquitous computing (or " ubicomp ") is a concept in software engineering , hardware engineering and computer science where computing is made to appear seamlessly anytime and everywhere. In contrast to desktop computing , ubiquitous computing implies use on any device, in any location, and in any format. A user intera... | https://en.wikipedia.org/wiki/Ubiquitous_computing |
The Ubuntu Forums is the official forum for the Ubuntu operating system. [ 1 ]
As of May 2022, The Ubuntu Forums has 2.1 million registered members and more than 2.2 million threads. [ 2 ] The Ubuntu Forums currently runs on the forum software vBulletin . [ 3 ]
On July 20, 2013 the site was compromised, with attacker... | https://en.wikipedia.org/wiki/Ubuntu_Forums |
The ucode system (written in lower case " ucode ") is an identification number system that can be used to identify things in the real world uniquely. Digital information can be associated with objects and places, and the associated information can be retrieved by using ucode.
Unique identification system for real worl... | https://en.wikipedia.org/wiki/Ucode_system |
In classical mechanics , the Udwadia–Kalaba formulation is a method for deriving the equations of motion of a constrained mechanical system . [ 1 ] [ 2 ] The method was first described by Anatolii Fedorovich Vereshchagin [ 3 ] [ 4 ] for the particular case of robotic arms , and later generalized to all mechanical syst... | https://en.wikipedia.org/wiki/Udwadia–Kalaba_formulation |
In organic chemistry , the Ugi reaction is a multi-component reaction involving a ketone or aldehyde , an amine , an isocyanide and a carboxylic acid to form a bis- amide . [ 1 ] [ 2 ] [ 3 ] [ 4 ] The reaction is named after Ivar Karl Ugi , who first reported this reaction in 1959.
The Ugi reaction is exothermic and ... | https://en.wikipedia.org/wiki/Ugi_reaction |
The ugly duckling theorem is an argument showing that classification is not really possible without some sort of bias . More particularly, it assumes finitely many properties combinable by logical connectives , and finitely many objects; it asserts that any two different objects share the same number of ( extensional )... | https://en.wikipedia.org/wiki/Ugly_duckling_theorem |
Uhuru was the first satellite launched specifically for the purpose of X-ray astronomy . It was also known as the X-ray Explorer Satellite , SAS-A (for Small Astronomy Satellite A , the first of the three-spacecraft SAS series), SAS 1 , or Explorer 42 . The NASA observatory was launched on 12 December 1970 into an ini... | https://en.wikipedia.org/wiki/Uhuru_(satellite) |
In Section 203(a) of the Central Utah Project Completion Act , the United States Congress authorized a federally authorized and funded replacement project to replace the Uinta and Upalco Units of the Central Utah Project (CUP) which were not constructed. The replacement project is the Uinta Basin Replacement Project (U... | https://en.wikipedia.org/wiki/Uinta_Basin_Replacement_Project |
The Uintah Indian Irrigation Project is the principal Indian irrigation project in the Uintah Basin . The United States Bureau of Indian Affairs designed and constructed this project. The project was authorized in 1906, soon after the US Indian Irrigation Service was established as part of the Bureau of Indian Affairs.... | https://en.wikipedia.org/wiki/Uinta_Indian_Irrigation_Project |
The Ukrainian Engineers' Society of America is an organization of Ukrainian engineers and students based in New York City . The society was founded in New York City on September 18, 1948, by a group of Ukrainian immigrants of the engineering profession. Their first annual meeting was held on November 20, 1948. Their g... | https://en.wikipedia.org/wiki/Ukrainian_Engineers'_Society_of_America |
Ulam's game , or the Rényi–Ulam game , is a mathematical game similar to the popular game of twenty questions . In Ulam's game, a player attempts to guess an unnamed object or number by asking yes–no questions of another, but one of the answers given may be a lie. [ 1 ]
Alfréd Rényi ( 1961 ) introduced the game in a 1... | https://en.wikipedia.org/wiki/Ulam's_game |
Ullmann's Encyclopedia of Industrial Chemistry is a major reference work related to industrial chemistry by chemist Fritz Ullmann , first published in 1914, and exclusively in German as "Enzyklopädie der Technischen Chemie" until 1984.
Ullmann's Encyclopedia of Industrial Chemistry is a major reference work related to... | https://en.wikipedia.org/wiki/Ullmann's_Encyclopedia_of_Industrial_Chemistry |
The Ullmann condensation or Ullmann-type reaction is the copper-promoted conversion of aryl halides to aryl ethers, aryl thioethers, aryl nitriles, and aryl amines. These reactions are examples of cross-coupling reactions . [ 1 ]
Ullmann-type reactions are comparable to Buchwald–Hartwig reactions but usually require h... | https://en.wikipedia.org/wiki/Ullmann_condensation |
The Ullmann reaction or Ullmann coupling , named after Fritz Ullmann , couples two aryl or alkyl groups with the help of copper. The reaction was first reported by Ullmann and his student Bielecki in 1901. It has been later shown that palladium and nickel can also be effectively used. [ 1 ] [ 2 ]
Aryl-Aryl bond format... | https://en.wikipedia.org/wiki/Ullmann_reaction |
Ulrich Hofmann (January 22, 1903 – July 5, 1986) was a German chemist known for his study of clay minerals and the pioneering use of electron microscopes in the study of carbonaceous materials . [ 1 ] [ 2 ] [ 3 ]
Hofmann was born in Munich in 1903 and the son of the German chemist Karl Andreas Hofmann . He studied che... | https://en.wikipedia.org/wiki/Ulrich_Hofmann |
Ulrich Müller (born 6 July 1940 in Bogotá ) is a German chemist who is known for his works on solid-state chemistry and the application of crystallographic group theory to crystal chemistry . [ 1 ] [ 2 ] He is the author of several textbooks on chemistry, solid-state chemistry , and crystallography. [ 1 ] [ 3 ] [ 4 ] [... | https://en.wikipedia.org/wiki/Ulrich_Müller |
Ulrike Diebold (born 12 December 1961, in Kapfenberg, Austria ) [ 1 ] is an Austrian physicist and materials scientist who is a professor of surface science at TU Vienna . [ 2 ] She is known for her groundbreaking research on the atomic scale geometry and electronic structure of metal-oxide surfaces. [ 3 ]
Diebold was... | https://en.wikipedia.org/wiki/Ulrike_Diebold |
In mechanical engineering , ultimate failure describes the breaking of a material. In general there are two types of failure: fracture and buckling . Fracture of a material occurs when either an internal or external crack elongates the width or length of the material. In ultimate failure this will result in one or m... | https://en.wikipedia.org/wiki/Ultimate_failure |
In engineering , the ultimate load [ 1 ] is a statistical figure used in calculations, and should (hopefully) never actually occur.
Strength requirements are specified in terms of limit loads (the maximum loads to be expected in service) and ultimate loads (limit loads multiplied by prescribed factors of safety).
It ... | https://en.wikipedia.org/wiki/Ultimate_load |
Ultimate reality is "the supreme, final, and fundamental power in all reality". [ 1 ] It refers to the most fundamental fact about reality, especially when it is seen as also being the most valuable fact. This may overlap with the concept of the Absolute in certain philosophies.
Anaximander ( c. 610 – c. 546 BCE ) bel... | https://en.wikipedia.org/wiki/Ultimate_reality |
Ultimate tensile strength (also called UTS , tensile strength , TS , ultimate strength or F tu {\displaystyle F_{\text{tu}}} in notation) [ 1 ] is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials, the ultimate tensile strength is close to the yield p... | https://en.wikipedia.org/wiki/Ultimate_tensile_strength |
The Ultra-Fast Flash Observatory ( UFFO ) Pathfinder is a space observatory measuring prompt emission of gamma-ray bursts (GRB) both in optical/UV and in X-ray range down to sub-second timescales for the first time. [ 1 ] Instead of turning the whole satellite towards GRB location like the Swift Gamma-Ray Burst Mission... | https://en.wikipedia.org/wiki/Ultra-Fast_Flash_Observatory_Pathfinder |
In astroparticle physics , an ultra-high-energy cosmic ray ( UHECR ) is a cosmic ray with an energy greater than 1 EeV (10 18 electronvolts , approximately 0.16 joules ), [ 1 ] far beyond both the rest mass and energies typical of other cosmic ray particles. The origin of these highest energy cosmic rays is not known. ... | https://en.wikipedia.org/wiki/Ultra-high-energy_cosmic_ray |
Ultra-high vacuum (often spelled ultrahigh in American English, UHV ) is the vacuum regime characterised by pressures lower than about 1 × 10 −6 pascals (1.0 × 10 −8 mbar ; 7.5 × 10 −9 Torr ). UHV conditions are created by pumping the gas out of a UHV chamber. At these low pressures the mean free path of a gas molecule... | https://en.wikipedia.org/wiki/Ultra-high_vacuum |
Ultra-large-scale system ( ULSS ) is a term used in fields including Computer Science , Software Engineering and Systems Engineering to refer to software intensive systems with unprecedented amounts of hardware , lines of source code , numbers of users , and volumes of data . The scale of these systems gives rise to ma... | https://en.wikipedia.org/wiki/Ultra-large-scale_systems |
Ultra-low-sulfur diesel ( ULSD ) is diesel fuel with substantially lowered sulfur content. Since 2006, almost all of the petroleum-based diesel fuel available in Europe and North America has been of a ULSD type.
The move to lower sulfur content allows for the application of advanced emissions control technologies that... | https://en.wikipedia.org/wiki/Ultra-low-sulfur_diesel |
Ultra-low particulate air ( ULPA ) is a type of air filter . A ULPA filter can remove from the air at least 99.999% of dust , pollen , mold , bacteria and any airborne particles with a minimum particle penetration size of 120 nanometres (0.12 μm , ultrafine particles ). A ULPA filter can remove—to a large extent but no... | https://en.wikipedia.org/wiki/Ultra-low_particulate_air |
An ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as 1 000 000 g (approx. 9 800 km/s² ). [ 1 ] There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge . Both classes of instruments find important uses in ... | https://en.wikipedia.org/wiki/Ultracentrifugation |
An ultracentrifuge is a centrifuge optimized for spinning a rotor at very high speeds, capable of generating acceleration as high as 1 000 000 g (approx. 9 800 km/s² ). [ 1 ] There are two kinds of ultracentrifuges, the preparative and the analytical ultracentrifuge . Both classes of instruments find important uses in ... | https://en.wikipedia.org/wiki/Ultracentrifuge |
In condensed matter physics , an ultracold atom is an atom with a temperature near absolute zero . At such temperatures, an atom's quantum-mechanical properties become important, especially through what's known as a "superfluid" , such as Superfluid Helium 4 .
To reach such low temperatures, a combination of several t... | https://en.wikipedia.org/wiki/Ultracold_atom |
In chronobiology , an ultradian rhythm is a recurrent period or cycle repeated throughout a 24-hour day. In contrast, circadian rhythms complete one cycle daily, while infradian rhythms such as the menstrual cycle have periods longer than a day. The Oxford English Dictionary 's definition of Ultradian specifies that it... | https://en.wikipedia.org/wiki/Ultradian_rhythm |
In functional analysis , an ultradistribution (also called an ultra-distribution [ 1 ] ) is a generalized function that extends the concept of a distributions by allowing test functions whose Fourier transforms have compact support . [ 2 ] They form an element of the dual space 𝒵′, where 𝒵 is the space of test functi... | https://en.wikipedia.org/wiki/Ultradistribution |
In physics , ultradivided matter is a family of states of matter characterised by a heterogeneous mixture of two or more different materials, where the interaction energy between the suspended phase is larger than kT. The term 'ultradivided matter' encapsulates several types of substance including: soap micelles , emul... | https://en.wikipedia.org/wiki/Ultradivided_matter |
Ultrafast X-rays or ultrashort X-ray pulses are femtosecond x-ray pulses with wavelengths occurring at interatomic distances . This beam uses the X-ray's inherent abilities to interact at the level of atomic nuclei and core electrons . This ability combined with the shorter pulses at 30 femtosecond could capture the ch... | https://en.wikipedia.org/wiki/Ultrafast_X-ray |
An ultrafast molecular process is any technology that relies on properties of molecules that are only extant for a very short period of time (less than 1e-9 seconds). Such processes are very important in areas such as combustion chemistry and in the study of proteins .
This chemical process -related article is a stub ... | https://en.wikipedia.org/wiki/Ultrafast_molecular_process |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.