La

La
Lanthanum is a soft, ductile, white metallic element which oxidises rapidly in air.
La2O3
Chemical formula for Lanthanum III Oxide.
LaB6
Chemical formula for Lanthanum Hexaboride.
LaBr3
Chemical formula for Lanthanum III Bromide.
LaC2
Chemical formula for Lanthanum Carbide.
LaCl3
Chemical formula for Lanthanum III Chloride.
Lacquer
A fast-drying usually clear coating that is highly flammable and dries by solvent evaporation only.
Lactic Acid

C3H6O3

Plays a role in various biochemical processes.

LAE
Abbreviation for sound exposure level.
LAeqT
There are a number of different noise criteria measurements used by local authorities to determine noise levels in the community.
Lag
The amount one wave is behind another in time.
Lagrangian Points
In a system of two large bodies (Sun-Earth or Earth-Moon), these are the points where a small third body will keep a fixed position relative to the other two.
lambda
A letter of the Greek alphabet.
Lambda
The lightest strange baryon, consisting of one up, one down, and one strange quark.
Lamberts Laws
The illuminance on a surface illuminated by light falling on it perpendicularly from a point source is proportional to the inverse square of the distance between the surface and the source.
Laminar Flow
Smooth flow in which no crossflow of fluid particles occur between adjacent streamlines, a flow conceived as made up of layers.
Laminate Ply
One layer of a laminated product.
Laminated
Made of thin layers.
Laminated Core
A core built up from thin sheets of metal insulated from each other.
Laminated Shim
A Shim made up of thin metal sheets soldered together but so that each layer can be easily peeled off.
LAN
Abbreviation of Local Area Network.
Lance-Wood
An elastic wood suitable where some degree of bending is required.
Land
That surface on the periphery of a rotary cutting tool, such as a milling cutter, drill, tap, or reamer, which joins the face of the flute or tooth to make up the basic cutting edge.
Landau Damping
The damping of a space charge wave by electrons which move at the phase velocity of the wave and gain energy transferred from the wave.
Landauer′s Principle
A principle which states that it doesn′t explicitly take energy to compute data.
Landfill Site
A carefully designed structure built into or on top of the ground in which rubbish is isolated from the surrounding environment.
Landing Weight
Normal maximum weight at which an aircraft is permitted to land.
Langasite
Alternative name for Lanthanum Gallium Silicate.
Langley
A unit of energy per unit area, equal to 1 gram-calorie per square centimeter, commonly employed in radiation theory.
Langmuir Probe
A small metallic conductor or pair of conductors inserted within a plasma in order to sample the plasma current.
Langmuir-Tonks Frequency
Also known as Plasma Frequency.
Lanthana
Alternative name for Lanthanum III Oxide.
Lanthanide
Elements 57-70 are called lanthanides.
Lanthanide Contraction
An effect that causes sixth period elements with filled 4f subshells to be smaller than otherwise expected.
Lanthanum
A soft, ductile, white metallic element which oxidises rapidly in air.
Lanthanum Carbide

LaC2

Used it to study the manufacture of certain types of superconductors and nanotubes.

Lanthanum Carbonate

La2(CO3)3

An ore of lanthanum metal, along with monazite.

Lanthanum Gallium Silicate
A piezoelectric material, with no phase transitions up to its melting point of 1470 C.

Lanthanum Hexaboride

LaB6

Used in hot cathodes, either as a single crystal or as a coating deposited by physical vapor deposition.

Lanthanum III Bromide

LaBr3

A colourless white powder used as a source of lanthanum in chemical synthesis.

Lanthanum III Chloride

LaCl3

Used as a mild Lewis acid to perform chemical reactions that usually require acidic conditions, such as converting aldehydes to acetals, under nearly neutral conditions.

Lanthanum III Oxide

La2O3

Used at a laboratory level to develop ferroelectric and in optical materials.

Lanthanum Sesquioxide
Alternative name for Lanthanum III Oxide.
Lanthanum Strontium Cobalt Ferrite
Being investigated as a material for intermediate temperature solid oxide fuel cell cathodes and as a membrane material for separation of oxygen from air.

Lanthanum Strontium Manganite
Commonly used in as a cathode material in commercially produced solid oxide fuel cells.

Lanthanum Trichloride
Alternative name for Lanthanum III Chloride.
Lap
A tool made of soft metal and charged with fine abrasives for precision finishing of metal surfaces.
Lap Joint
A joint between two overlapping members.
Lap Winding
An armature winding in which opposite ends of each coil are connected to adjoining segments of the commutator so that the windings overlap.
Laplace Marquis Pierre Simon de
French mathematician and astronomer who formulated the theory of probability.
Laplace Transform
The Laplace transform is used to convert certain types of inital value problems into algebra problems.
Laplacian
The divergence of a gradient.
Lapping
A surface finishing operation used to achieve a fine polish and close tolerances.
Lapping Compound
Light, abrasive material used for finishing a surface.
Lapse Rate
The rate at which temperature decreases with height in the atmosphere.
Larch
An extremely durable wood used for rough work. It warps a lot when dried, but can be polished to a fine finish when dry.
Lard Oil
An oil made from animal fats usually mixed with mineral oils to reduce its cost and improve its qualities. Used in engineering as a cutting oil.

Large Scale Integration
An integrated circuit containing 1,000 to 2,000 logic gates or up to 64,000 bits of memory.
Larmor Radius
The radius of the path of a charged particle moving in a magnetic field and transverse to the field lines.
Laser
An acronym for light amplification by stimulated emission of radiation.
laser Cooling
A technique that uses laser beams to slow down the motion of atoms and cool them to temperatures a few millionths of a degree above absolute zero.
Laser Diode
A laser which uses a forward biased semiconductor junction as the active medium.
Laser Soldering
Method of soldering in which the heat required to reflow a solder interconnection is provided by a laser.
Laser Vibrometer
A sensing system which uses laser beams to measure the motion of a vibrating surface.
Latch
A device that fastens one thing to another, but is subject to ready release so that the things may be separated.
Latent Energy
The internal energy associated with the phase of a system.
Latent Heat
The amount of heat required to melt (or vapourize) 1 kilogram of a substance.
Latent Heat of Evaporation
The amount of heat required to vapourize 1 kilogram of a substance.
Latent Heat of Fusion
The amount of heat required to melt 1 kilogram of a substance.
Latent Vector
Another name for Eigenvector.
Lath
The material used to attach stucco or plaster to the framing of a building.
Lathe
A machine tool which spins a block of material to perform various operations to create an object which has symmetry about an axis of rotation.
Lathe Tool
Cutting tool for lathes and other turning machines.
Latin Square
An n by n array of numbers in which only n numbers appear. No number appears more than once in any row or column.
Latitude
The angular distance of a point on the Earth from the equator.
Latten
Elizabethan term for brass, probably of Dutch origin.
Lattice
An orderly arrangement of atoms in a material.
Lattice Constant
Refers to the constant distance between unit cells in a crystal lattice.
Lattice Parameter
The combination of unit cell edge lengths and interaxial angles that defines the unit cell geometry.
Lattice Point
A point with integer coordinates.
Latus Rectum
A chord of an ellipse passing through a focus and perpendicular to the major axis of the ellipse.
Laue Pattern
The pattern produced on a photographic film when high-frequency electromagnetic waves are fired at a crystalline solid.
Laughing Gas
Nitrous oxide, an anaesthetic.
Lava
Hot liquid rock that flows out of a volcanic vent.
Lavoisier, Antoine Laurent
Often referred to as the father of modern chemistry he was the first to grasp the true explanation of combustion. He contended that fire was the result of rapid union of the burned material with oxygen.
Law of Areas
Kepler′s second law states: Each planet moves in such a way that the imaginary line joining it to the sun sweeps out equal areas in equal times.
Law of Averages
The average of independent observations of random variables that have the same probability distribution is increasingly likely to be close to the expected value of the random variables as the number of observations grows.
Law of Combining Volumes
When gases react, they do so in a definite proportion by volume, if the volumes are measured at the same pressure and temperature.
Law of Conservation of Mass
There is no change in total mass during a chemical change.
Law of Definite Proportions
When two pure substances react to form a compound, they do so in a definite proportion by mass.
Law of Large Numbers
In repeated, independent trials with the same probability p of success in each trial, the percentage of successes is increasingly likely to be close to the chance of success as the number of trials increases.
Law of Magnetism
Like poles repel; unlike poles attract.
Law of Multiple Proportions
When one element can combine with another to form more than one compound, the mass ratios of the elements in the compounds are simple whole-number ratios of each other.
Law of Parsimony
The suggestion that the simpler a theory is, the better it is.
Law of the First Wavefront
The first wavefront falling on the ear determines the perceived direction of the sound.
Lawrencium
The only known isotope has a half life of 8 seconds.
Lawson Criterion
A criterion specifying the product of density and confinement time required to satisfy some power balance condition in a fusion reactor.
Lay
Direction of the predominant surface pattern, which is determined by the production method.
Layup
The placement of layers of reinforcement in a mould.