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Lake acidification
Lake acidification is the process by which a lake's water becomes more acidic, caused mainly by acid rain and acid mine drainage. It killed fish in Scandinavian and North American lakes in the 1970s and 1980s.
Lake Karachay
Lake Karachay, also called Karachai, was a small lake at the Mayak nuclear site in the southern Urals, Russia, that held liquid radioactive waste from 1951.
Lake sediment coring
Lake sediment coring is the extraction of cylindrical sediment columns from lake beds, using gravity, piston, vibracorer, and drilling systems to recover layered records of past environments for paleolimnology, paleoclimatology, and contamination studies.
Lake stratification
Lake stratification, or thermal stratification, is the layering of a lake's water by density, typically into a warm epilimnion, a cold hypolimnion, and a thermocline between.
Lake Suguta
Lake Suguta was a large Pleistocene and Holocene lake filling the Suguta Valley in the northern Kenya Rift, reaching about 300 m deep during the African Humid Period.
Lake-effect snow
Lake-effect snow is heavy snow produced when cold, dry air passes over a warmer unfrozen lake and forms narrow snow bands over the downwind shore, especially near the Great Lakes.
Lakh (लाख)
Lakh (लाख), also spelled lac, is a unit in the Indian numbering system equal to one hundred thousand, the standard large-number word in South Asian finance and everyday speech.
Laki
Laki, or Lakagígar, is a 27 km volcanic fissure in southern Iceland whose 1783 to 1784 eruption caused famine that killed about a fifth of Iceland's population.
Lakkor Tso Salar lithium project
The Lakkor Tso Salar lithium project (拉果错盐湖锂矿) is a lithium brine mining operation at Lakkor Tso, a salt lake in Xizang, China, owned by Zijin Mining Group.
Lalor Mine
The Lalor Mine is an underground zinc, copper, and gold mine near Snow Lake, Manitoba, operated by Hudbay Minerals on a deposit it discovered in 2007; production began in 2012.
Laman graph
A Laman graph is a graph on n vertices with exactly 2n − 3 edges whose subsets stay sparse, making it minimally rigid in the plane by Laman's 1970 theorem.
Lamb shift
The Lamb shift is the small energy difference between the 2S and 2P levels of hydrogen, measured by Willis Lamb in 1947 and explained through renormalized quantum electrodynamics.
Lamb–Chaplygin dipole
The Lamb–Chaplygin dipole, found independently by Horace Lamb and Sergei Chaplygin around 1900, is an exact solution of the Euler equations: two counter-rotating vortices that translate without changing shape.
Lambda Andromedae
Lambda Andromedae is a chromospherically active giant star in the constellation Andromeda, an RS Canum Venaticorum variable with a rotation period of about 54 days.
Lambda Aurigae
Lambda Aurigae (λ Aurigae, λ Aur) is a Sun-like star in the constellation Auriga, about 41 light-years away, known as a nearby solar analog used to calibrate radial-velocity instruments.
Lambda calculus
The lambda calculus, also written λ-calculus, is a formal system invented by Alonzo Church in the 1930s that expresses computation through function definition and application, computing exactly what Turing machines compute.
Lambda Cephei
Lambda Cephei, abbreviated λ Cep and cataloged as HD 210839, is a hot, luminous O-type supergiant star in Cepheus and one of the brightest runaway O stars.
Lambda cube
The lambda cube is Henk Barendregt's arrangement of eight typed lambda calculi, formed from the simply typed lambda calculus by adding polymorphism, type operators, and dependent types.
Lambda Orionis
Lambda Orionis, also known as Meissa, is a massive triple star system about 1,500 light years away that marks the head of Orion and dominates the Lambda Orionis star-forming region.
Lambda point
The lambda point is the temperature, about 2.1768 K, at which liquid helium-4 transitions into the superfluid phase helium II; it is named for the lambda-shaped peak in the heat capacity curve.
Lambda Scorpii
Lambda Scorpii (λ Scorpii), also known as Shaula, is a bright, naked-eye star at the tip of the Scorpion's tail in Scorpius, actually a triple system.
Lambda Velorum
Lambda Velorum (λ Velorum), officially named Suhail after its traditional Arabic name, is a magnitude 2.2 orange supergiant in the southern constellation Vela, about 545 light-years from Earth.
Lambda-CDM model (ΛCDM)
Lambda-CDM, or ΛCDM, is the standard six-parameter model of cosmology, describing a flat 13.8-billion-year-old universe of cold dark matter and dark energy, though it faces tensions in measurements of the Hubble constant.
Lambek calculus
The Lambek calculus, or syntactic calculus, is a substructural logic introduced by Joachim Lambek in 1958, in which grammatical well-formedness is decided by logical derivability over syntactic types.
Lambert W function
The Lambert W function, also called the omega function, is the multivalued inverse of w e^w, with infinitely many branches, two of which take real values.
Laminar flow
Laminar flow, also called lamellar flow, is a regime of fluid motion in smooth, parallel layers with no mixing, occurring when the Reynolds number is low.
Laminar–turbulent transition
Laminar–turbulent transition, also known as transitional flow, is how smooth laminar flow breaks down into turbulence, typically as the Reynolds number increases past a critical value.
Laminated glass
Laminated glass, also known as laminated safety glass, is two or more glass plies bonded by a polymer interlayer, typically PVB, so fragments stay attached after breakage.
Laminography
Laminography is a tomographic X-ray and neutron imaging method that reconstructs the 3D structure of flat, plate-like objects, such as circuit boards and paintings, from a tilted rotation axis.
Lamivudine
Lamivudine (3TC), sold as Epivir, is a nucleoside reverse transcriptase inhibitor used in combination therapy for HIV-1 and, at a lower dose, for chronic hepatitis B.