Li

Li
Lithium is a soft, silver metal, and is the first member of the alkali group of metals.
Li2NH
Chemical formula for Lithium Imide.
Li2
Chemical formula for Lithium I Oxide.
Li2O2
Chemical formula for Lithium I Peroxide.
Li3N
Chemical formula for Lithium I Nitride.
LiBr
Chemical formula for Lithium I Bromide.
Libration
The apparant rocking motion of an orbiting body.
Lickey, Sir Robert
Scottish engineer who designed the WW2 fighter Hawker Hurricane and the first Harrier vertical take-off jet.
LiCl
Chemical formula for Lithium I Chloride.
LiF
Chemical formula for Lithium I Fluoride.
Life Cycle Analysis
The investigation and evaluation of the environmental impacts of a given product or service caused or necessitated by its existence.
Lifetime Cancer Risk
The probability of contracting cancer over the course of a lifetime.
Lift
The lifting force on a flying object.
Lift Bridge
The deck is raised vertically like a massive elevator.
Lift Coefficient
A dimensionless value that allows the comparison of lift incurred by different sized and different shaped bodies. A positive lift coefficient represents lift, whilst a negative lift coefficient represents downforce.
Lifting Body
An aircraft that uses the shape of its body to generate lift instead of using wings.
Ligand
A molecule or ion that binds to a metal cation to form a complex.
Light
Electromagnetic radiation that is visible to the unaided human eye.
Light Beam
A collection of rays that may be parallel, convergent, or divergent.
Light Bulb
A device that takes an electric supply and generates light.
Light Dependent Resistor
A layer of Cadmium Sulphide material that changes resistance according to the amount of light falling on it.
Light Duty Engine
An engine that is designed to be normally operated at substantially less than its peak output.
Light Emitting Diode
A diode that emits light when current is passed through it.
Light Loss Factor
Used to calculate illuminance loss after a given period of time and under given conditions, like dirt accumulation and heat buildup in the fixture.
Light Metal
One of the low-density metals, such as aluminum, magnesium, titanium, beryllium, or their alloys.
Light Ray
A line that represents the path of light in a given direction.
Light Reflectance
The measure of light reflectance is that fraction of the specified incident light is reflected by the surface.
Light Scattering
When light passes through a medium that is not perfectly homogeneous, the irregularities in the medium scatter some of the light in all directions.
Light Year
The light year is defined as the distance travelled by electromagnetic radiation in one tropical year.
Lighthouse Tube
An electron tube shaped like a lighthouse that is designed to handle large amounts of power at uhf frequencies.
Lightning
An atmospheric discharge of electricity usually accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms.
Lignite
A type of coal with lowest carbon content (25% to 35%) and a low heat value called "brown coal", used mainly for electric power generation.

Lignum Vitae
A very hard wood.
LiH
Chemical formula for Lithium I Hydride.
LiI
Chemical formula for Lithium I Iodide.
LiIon
Abbreviation of Lithium Ion Battery.
Limescale
Hard, off-white, chalky deposit found in kettles, hot-water boilers and the inside of inadequately maintained hot-water central heating systems.
Limestone
Naturally occuring Calcium Carbonate.
Limit
The number you approach as you plug values into a function, and the values get closer and closer to a given number.
Limit of Resolution
The limit to the performance of a lens imposed by the diffraction pattern resulting from the finite aperture of the optical system.
Limit Switch
A sensor used to determine the end of travel on a linear motion assembly.
Limited Slip Differential
Differential with mechanism to limit the amount of differential speed between the two outputs.
Limiting Reagent
The reactant that will be exhausted first.
Lin Log Amplifier
An amplifier in which the response is linear for weak signals and logarithmic for large signals.
Linac
An abbreviation for linear accelerator.
Line
Line is one of the basic undefined terms in Euclidian geometry, but one intuitive definition is as follows: A straight set of points that continue on to infinity in both directions. Although a line is of infinite length, it has thickness and width of zero.
Line Graph
A diagram showing a system of connections or interrelations between two or more things by using lines.
Line of Action
The line of action of a force is the infinite line defined by extending along the direction of the force from the point where the force acts.
Line of Best Fit
A straight line used as a best approximation of a summary of all the points in a scatter-plot.
Line of Reflection
The line that is reflected over in a reflection.
Line of Sight
A straight line between two points.
Line Plot
A graphical display of a set of data where each separate piece of data is shown as a dot or mark above a number line.
Line Segment
A piece of a line which includes two definite endpoints and all points in between them.
Line Source
A continuous line acoustic source such as a vibrating string.
Line Spectra
Spectra generated by excited substances. Consists of radiation with only specific wavelengths.
Line Symmetry
If a figure is divided by a line and both divisions are mirrors of each other, the figure has line symmetry.
Line Vortex
Idealized vortex in which vorticity is zero everywhere except along a line in space where it is infinite.
Linear
Having an output that varies in direct proportion to the input.
Linear Absorption Coefficient
The fractional decrease in transmitted intensity per unit of absorber thickness.
Linear Accelerator
Particle accelerator in which charged particles are accelerated in a straight line, either by a steady electrical field or by means of radiofrequency electric fields.
Linear Actuator
An actuator that creates motion in a straight line.
Linear Bus
A network topology in which each computer attaches directly to a common cable.
Linear Combination of Vectors
A vector v is a linear combination of the vectors v1, ..., vk if there exist scalars a1, ..., ak such that v = a1v1 + ... + akvk.
Linear Density
Mass per unit length.
Linear Distortion
Magnitude and phase distortion.
Linear Equations
A first order differential equation is linear if it has the form: y′=A(x)B(y)
Linear Foot
Term used loosely to describe a one-foot length of any long, narrow object. Primarily used to distinguish it from a square or cubic foot.
Linear Function
A function of the form y=ax+b.
Linear Impedance
An impedance in which a change in current through a device changes in direct proportion to the voltage applied to the device.
Linear Momentum
A vector quantity equal to the product of an object's mass and its velocity.
Linear Motion
Motion in a straight line.
Linear Motor
A motor consisting of two parts, typically a moving coil and stationary magnet track.
Linear Phase Response
Any system which accurately preserves phase relationships between frequencies
Linear Region
A transistor operating mode where the collector current is proportional to the base current.
Linear Regression
An attempt to model the relationship between two variables by fitting a linear equation to observed data.
Linear Space
A collection of vectors which means that the space is an additive Abelian group and, in addition, its elements can be multiplied by scalars.
Linear System
A system is linear if for every element in the system, the response is proportional to the excitation.
Linear Thermal Expansion
Most substances expand when heated and contract when cooled.
Linear Variable Differential Transformer
An inductance element that produces an electrical output proportional to the displacement of a separate movable core; used to measure position.
Linke Turbidity Factor
A measure of atmospheric turbidity, equal to the ratio of total optical depth to the Rayleigh optical depth.
Links
Links to other Science and Engineering Resources on the Internet
Linseed Oil
Obtained from the seeds flax. Originally used in the production of paints.
Lintel
The horizontal beam placed over an opening.
Linux
An open source PC operating system.
LiO2
Chemical formula for Lithium Superoxide.
Lip of a Drill
The sharp cutting edge on the end of a twist drill.
Lip Seal
An elastomeric or metallic seal that prevents leakage in dynamic and static applications by a scraping or wiping action at a controlled interference between itself and the mating surface.
Lipid
A diverse group of organic molecules that contain long hydrocarbon chains or rings and are hydrophobic.
Lipophilic
Refers to a substance′s solubility in fat.
Lipowitz Alloy
A low melting point alloy used to form shields in radiotherapy.

Liquefaction
The transformation of a gas into a liquid.
Liquefied Hydrogen
Hydrogen in liquid form.
Liquefied Natural Gas
Natural gas that has been refrigerated to cryonic temperatures where the gas condenses into a liquid.
Liquefied Petroleum Gas
A flammable mixture of hydrocarbon gases used as a fuel, primarily mixes of propane, butane or both.
Liquid
Matter with a definite volume that takes the shape of its container.
Liquid Air Cycle Engine
A rocket engine in which the oxidizer is liquid air obtained by liquefaction of the air entering the air-breathing inlet.
Liquid Air Rocket
A rocket engine in which the oxidizer is liquid air obtained by liquefaction of the air entering the air-breathing inlet.
Liquid Crystal Display
A thin and flat display device made up of a number of colour or monochrome pixels arrayed in front of a light source or reflector.
Liquid Crystal Polymer
A type of thermoplastic, melt processible, with high orientation in moulding, improved tensile strength, and high-temperature capability.
Liquid Desiccant
A hygroscopic liquid, such as glycol, used to remove water from other fluids.
Liquid Organic Hydrogen Carriers
These are liquid pumpable, easily rechargeable and have acceptable gravimetric storage densities, similar volumetric storage densities to cryogenic liquid hydrogen.
Liquidus
In a constitution or equilibrium diagram, the locus of points representing the temperatures at which the various compositions in the system begin to freeze on cooling or to finish melting on heating.
LISP
Abbreviation for list processing.
Lissajou′s Figures
The pattern traced out when the displacements of two simple harmonic motions are traced in the x and y direction.
Litharge
Lead monoxide varies in colour from pale yellow to brown, used in the manufacture of glass, paints, varnishes and glazes.
Lithium
A soft, silver metal, and is the first member of the alkali group of metals.
Lithium I Bromide

LiBr

White crystalline solid.

Lithium I Chloride

LiCl

White crystalline solid.

Lithium I Fluoride

LiF

White crystalline solid.

Lithium I Hydride

LiH

White to grey crystalline solid.

Lithium I Iodide

LiI

White crystalline solid.

Lithium I Nitride

Li3N

Purple or red crystalline solid.

Lithium I Oxide

Li2O

White crystalline solid.

Lithium I Peroxide

Li2O2

White crystalline solid.

Lithium Imide

Li2NH

A white solid that turns brick red in sunshine.

Lithium Ion Battery
Lithium ions are added to a carbon electrode instead of using metallic lithium as the anode.
Lithium Iron Sulphide Battery
Lithium alloy anode and an iron sulphide cathode suspended in an electrolyte molten salt solution.
Lithium Metal Anode Battery
Lithium metal is an ideal anode material for rechargeable batteries due to its extremely high theoretical specific capacity.
Lithium Polymer Battery
The battery has a lithium anode that is separated from the cathode by a thin polymer electrolyte.
Lithium Sulphur Battery
A rechargeable battery with a high energy density.
Lithium Superoxide

LiO2

Yellow crystalline solid.

Lithosphere
The upper layer of the solid Earth, both continental and oceanic, which is composed of all crustal rocks and the cold, mainly elastic, part of the uppermost mantle.
Litmus
A mixture of pigments extracted from certain lichens that turns blue in basic solution and red in acidic solution.
Litmus Paper
Paper impregnated with litmus, usually cut in narrow strips.
Litre
A derived SI unit of volume.
Litre Atmosphere
A unit of work or energy used in the study of confined gases.
litres per 100km
Unit of fuel consumption used in the automotive industry.
Little End
The gudgeon pin end, the part of the conrod that fits to the piston.
Little Endian
A byte ordering system where the least-significant byte of a multiple byte number is placed in memory at the lowest address.
Live Centre
A centre that revolves with the work.
Live End Dead End
An acoustical treatment plan for rooms in which one end is highly absorbent and the other end reflective and diffusive.
Live Room
Room characterized by a relatively small amount of sound absorption.
Lixivial Salts
Salts prepared by lixiviations.
Lixiviation
Separation of soluble from unsoluble solid substances by soaking the mixture of solids and removing the resulting solution which contained the soluble material.
Lixivium
A solution produced by lixiviation. Sometimes used as a general synonym for "Solution".