42,772 articles
Engine efficiency
Engine efficiency is the fraction of energy supplied to an engine that is converted into useful work, always below 100% because some heat must be rejected.
Engineered living material for carbon capture
An engineered living material for carbon capture is a construction material containing living microorganisms, typically cyanobacteria, that draw CO2 from the air and store it as biomass or carbonate minerals.
Engineering fit
An engineering fit is the degree of tightness or looseness between two mating mechanical parts, such as a shaft in a hole, classified as clearance, transition, or interference.
Engineering notation
Engineering notation, or ENG notation, is a version of scientific notation in which the exponent of 10 is always a multiple of 3, matching SI prefixes like kilo and milli.
English Longitudinal Study of Ageing
The English Longitudinal Study of Ageing (ELSA) is a panel study following a representative cohort of people in England aged 50 and over, first interviewed in 2002.
English units
English units, also known as the English system of units, are the traditional weights and measures of England, such as the inch, foot, and pound.
Enhanced Fujita scale
The Enhanced Fujita scale (EF scale) rates tornado intensity from EF0 to EF5 based on damage; it has been used by the US National Weather Service since 2007.
Enhanced oil recovery
Enhanced oil recovery (EOR), also called tertiary recovery, injects fluids, gases, chemicals, or heat into an oil reservoir to alter rock or fluid properties and produce more oil.
Enhanced sampling
Enhanced sampling is a family of molecular dynamics algorithms that modify the energy landscape so energy barriers are crossed more often, with reweighting to recover the unbiased ensemble.
Enhanced weathering
Enhanced weathering is a carbon removal method that spreads crushed silicate rock on farmland or coasts, dissolving it to convert atmospheric CO2 into ocean-stored bicarbonate.
Enhancement factor (gas absorption)
The enhancement factor in gas absorption is the ratio of absorption rate with reaction to purely physical absorption; it always exceeds 1 and is central to CO2 capture.
Ennio De Giorgi
Ennio De Giorgi (1928–1996) was an Italian mathematician at the Scuola Normale Superiore in Pisa, known for his regularity theorem for elliptic equations and Γ-convergence.
Enol
An enol, also called an alkenol, is a molecule with a hydroxyl group bonded to a carbon of a carbon–carbon double bond; the name contracts alkene and alcohol.
Enolate
An enolate is an anion formed by removing a proton from the carbon next to a carbonyl group of an aldehyde or ketone, key to forming carbon–carbon bonds.
Enolate and carbanion alkylation
Enolate and carbanion alkylation is the formation of a carbon–carbon bond by SN2 reaction of an enolate with an sp3 electrophile such as an alkyl halide.
Enone
An enone, a contraction of "alkene ketone", is an α,β-unsaturated ketone whose conjugated double bond makes it a single reactive unit, exemplified by cyclohex-2-en-1-one and defined by dual electrophilic sites.
Enone–alkene cycloadditions
Enone–alkene cycloaddition is a photochemical [2+2] cycloaddition in which an excited enone reacts with an alkene to form a cyclobutane, a widely used reaction in organic synthesis.
Enormous Lyman-alpha nebula
An enormous Lyman-alpha nebula (ELAN) is a vast cloud of glowing hydrogen gas, hundreds of kiloparsecs across, seen in Lyman-alpha light around a quasar at redshift z > 2.
Enoxacin
Enoxacin is a synthetic fluoroquinolone antibiotic developed by the Japanese company Dainippon and sold as Penetrex, used mainly for urinary tract infections, gonorrhea, and skin infections before withdrawal.
Enriched category
An enriched category is a category-like structure whose hom-sets are replaced by objects of a monoidal base category, yielding ordinary categories, metric spaces, and 2-categories as instances.
Enriched uranium
Enriched uranium is uranium in which the fissile isotope U-235 is increased above its natural 0.7 percent abundance, allowing fission chain reactions in power reactors, naval propulsion, and nuclear weapons.
Enrico Bombieri
Enrico Bombieri, born 1940 in Milan, is an Italian mathematician and 1974 Fields Medalist known for the Bombieri–Vinogradov theorem, and Professor Emeritus at the Institute for Advanced Study in Princeton.
Enrico Bonatti
Enrico Bonatti is an Italian marine geologist known for work on mantle rocks exposed on the ocean floor and the start of seafloor spreading in the Red Sea.
Enrico Costa (astrophysicist)
Enrico Costa (born 1944) is an Italian astrophysicist known for the 1997 discovery of gamma-ray burst afterglows with the BeppoSAX satellite and for co-inventing the Gas Pixel Detector.
Enrico Fermi
Enrico Fermi (1901–1954) was an Italian-born physicist who created the world's first nuclear reactor, developed Fermi statistics and beta-decay theory, and won the 1938 Nobel Prize in Physics.
Enrico Fermi Award
The Enrico Fermi Award, formally the Enrico Fermi Presidential Award, is a U.S. presidential science award established in 1956 in memory of physicist Enrico Fermi.
Enrico Ramirez-Ruiz
Enrico Ramirez-Ruiz is a Mexican-born theoretical astrophysicist, professor and chair of astronomy at UC Santa Cruz, known for interpreting the 2017 gravitational-wave event GW170817 as a kilonova that forged heavy r-process elements.
Enrique Iglesia
Enrique Iglesia, born in Havana, Cuba, in 1954, is a chemical engineer known for heterogeneous catalysis research, long a professor at UC Berkeley and now at Purdue University.
Enrique Marcatili
Enrique Marcatili was an Argentine-educated physicist at Bell Laboratories whose 1969 and 1973 papers on optical waveguides became standard references cited into the silicon photonics era.
Enrique Schisterman
Enrique Fabian Schisterman is an American reproductive epidemiologist and biostatistician who chairs biostatistics, epidemiology, and informatics at the University of Pennsylvania and led the EAGeR low-dose aspirin trial.