Al

Al
Aluminium is the basis for a number of alloys.
Al2Br6
Chemical formula for Aluminium Bromide.
Al2I6
Chemical formula for Aluminium Iodide.
Al2O3
Chemical formula for aluminium oxide.
Al2O32H2O
Chemical formula for Bauxite.
Al2S3
Chemical formula for Aluminium Sulphide.
Al5Lu3O12
Chemical formula for Lutetium Aluminium Garnet.
Alabamine
The name originally proposed for Astatine.
Alanine

C3H7NO2

An a-amino acid. It plays a key role in glucose-alanine cycle between tissues and liver.

Albedo
The ratio of the amount of radiation reflected from an object's surface compared to the amount that strikes it.
Albedometer
An instrument used for the measurement of the reflecting power, the albedo, of a surface.
Alcian Blue

C56H68Cl4CuN16S4

A phthalocyanine dye that contains copper.

AlCl3
Chemical formula for Aluminium Chloride.
Alclad
Alclad is a trademark of Alcoa used as a generic term to describe corrosion resistant aluminium sheet formed from high-purity aluminium surface layers metallurgically bonded to high strength aluminium alloy core material.
Alcohol
An alcohol is an organic compound with a carbon bound to a hydroxyl group.
Alcohol Brine
A water and alcohol solution, which remains as a liquid below 0°C.
Alcohol by Volume
A standard measure of how much alcohol is contained in an alcoholic beverage, expressed as a percentage of total volume.
Alcohol by Weight
A measure of how much alcohol is in a beverage, expressed as a percentage of the total beverage weight.
Alcohol Fermentation
The anaerobic conversion of glucose to ethanol via anaerobic glycolysis.
Alcohol Thermometer
A liquid-in-glass thermometer containing an alcohol liquid, such as ethanol.
ALCONS
The measured percentage of Articulation Loss of Consonants by a listener.
Aldehyde
Prepared by the oxidation of primary alcohols so that the OH group loses its hydrogen to give an oxygen joined by a double bond to a carbon atom.
Alder
This wood is very durable in water and not so durable in dry conditions. Historically it was used a lot in pumps, piles and sluices.
Aldose
A simple sugar in which the carbonyl carbon atom is an aldehyde.
Aldosterone

C21H28O5

A hormone that causes the tubules of the kidneys to retain sodium and water.

AlF3
Chemical formula for Aluminium Fluoride.
Alfven, Hannes
Swedish plasma physicist who won the 1970 Nobel Prize in Physics for his work developing the theory of magnetohydrodynamics.
Alfven, Hannes Olof Gosta
Won the 1970 Nobel Prize in Physics for fundamental work and discoveries in magneto-hydrodynamics with applications in different parts of plasma physics.
Alfven Waves
Waves moving perpendicularly through a magnetic field.
Algae
A large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms.
Algaecide
A chemical that when added to a solution prevents the growth of fungus and algae.
Algal Bloom
Sudden spurts of algae growth, which can affect water quality adversely and indicate potentially hazardous changes in local water chemistry.
Algebra
First major treatise written by Al-Khawarizmi in AD 810.
Algebra Books
Lists all Algebra Books in the Encyclopaedia
Algebra Calculations
Lists all Algebra Calculations in the Encyclopaedia
Algebra Conversions
Lists all Algebra Conversions in the Encyclopaedia
Algebra Weblinks
Lists all Algebra Weblinks in the Encyclopaedia
Algebraic
Defined by the basic algebra operations of addition, subtraction, multiplication (including powers), and division.
Algebraic Equation
An equation of the form f(x)=0 where f is a polynomial.
Algebraic Multiplicity of an Eigenvalue
The algebraic multiplicity of an eigenvalue c of a matrix A is the number of times the factor (t-c) occurs in the characteristic polynomial of A.
Algebraic Number
A number that is the root of an algebraic polynomial.
Algol
A high-level programming language developed in the 1950s.
Algorithm
A logical sequence of instructions that explain how to accomplish a task. It must explain exactly how to go from one step to the next and have a finite amount of steps.
AlH3
Chemical formula for Aluminium Hydride.
Alias
A false lower frequency component that appears in sampled data acquired at too low a sampling rate.
Aliasing
The erroneous interpretation of high-frequency signals as lower-frequency signals.
Alidade
That part of an optical measuring instrument comprising the optical system, indicator, vernier, etc.
Align
To adjust or set to a line or centre.
Aligning Punch
A tool shaped like a thin rod used to make sure holes line up when assembling two or more components.
Alignment
A condition whereby the axes of machine components are either coincident, parallel or perpendicular, according to design requirements, during operation.
Alignment Pin
A pin or stud used to align one part with another.
Alimentary Canal
A long tube in the body through which food passes along so that it can be digested.
Aliphatic
An organic compound that does not contain ring structures.
Aliquot
A sample of precisely determined amount taken from a material.
Alkali
A substance that dissolves in water to give a solution of aqueous hydroxide ions that is capable of turning red litmus blue.
Alkali Fuel Cell
Operate on compressed hydrogen and oxygen and generally use a solution of potassium hydroxide in water as their electrolyte. Operating temperatures inside alkali cells are around 150 to 200°C.
Alkali Metal
A metal in group IA of the periodic table that form strongly alkaline hydroxides.
Alkaline
Having a pH greater than 7.
Alkaline Air
An old name for ammonia gas.
Alkaline Battery
A storage battery which uses an alkaline electrolyte.
Alkaline Earth
An oxide of an alkaline earth metal, which produces an alkaline solution in reaction with water.
Alkaline Earth Metal
A metal in group IIA of the periodic table.
Alkaline Error
A systematic error that occurs when glass electrodes are used to read the pH of an extremely alkaline solution.
Alkaline Water Electrolysis
A solution of 2040% sodium hydroxide or potassium hydroxide aqueous solution is used for electrolyte instead of pure water, since pure water is highly resistive to electricity.
Alkalinity
A measure of a material's ability to neutralize acids.
Alkaloid
A class of bitter-tasting, basic organic compounds with nitrogen-containing rings.
Alkalosis
A metabolic condition in which blood pH decreases, usually the result of a metabolic condition or vomiting.
Alkane
A series of organic compounds with general formula CnH2n+2.
Alkene
A compound that consists of only carbon and hydrogen, that contains at least one carbon-carbon double bond.
Alkoxide
An ionic compound formed by removal of hydrogen ions from the hydroxyl group in an alcohol using reactive metals.
Alkyl
A molecular fragment derived from an alkane by dropping a hydrogen atom from the formula -CnH2n+1.
Alkyl Halide
An alkyl group attached to a halogen atom.
Alkylphenol
A family of organic compounds obtained by the alkylation of phenols.
Alkyne
A compound that consists of only carbon and hydrogen, that contains at least one carbon-carbon triple bond.
All Electric Range
The distance over a given drive cycle that a hybrid vehicle can travel on electric power only.
All Terrain Vehicle
A vehicle used in rough surface conditions.
Allen Key
A hexagonal shaped tool in cross section that is used to turn allen screws.
Allen Type Bolt
A bolt with a recessed hex shaped head.
Allergen
A substance that causes an allergic reaction in individuals sensitive to it.
Allo-
A prefix that designates the more stable of a pair of geometric isomers.
Allobar
A form of an element that has isotopic abundances that are different from the naturally occuring form.
Allomer
Substances with different chemical composition but the same crystalline form.
Allosteric Activator
Any molecule which positively modulates the activity of an allosteric enzyme.
Allosteric Effect
A change in the behaviour of one part of a molecule caused by a change in another part of the molecule.
Allosteric Enzyme
A regulatory enzyme, with catalytic activity modulated by the noncovalent binding of a specific molecule at a site other than the active site.
Allosteric Site
The specific site on the surface of an allosteric enzyme molecule, distinct from the active site, to which a modulator molecule binds.
Allotriomorphic Crystal
A crystal having a normal lattice structure, but with an imperfect outward shape due to the influence of its surroundings.
Allotropy
The reversible phenomenon by which certain metals may exist in more than one crystal structure.
Allowance
The prescribed difference in dimensions of mating parts to provide a certain class of fit.
Alloy
A metal produced by mixing other metals.
Alloy Wheel
A generic term used to describe any non-steel road wheel. The usual alloys are either aluminum or magnesium.
Alloying Elements
Chemical elements added for improving the properties of the finished materials.
Allusive Listening
Allusive listening is a presumed listening mode that may be said to occur where a listener relates moments or features of the music to similar moments or features in other musical works.
Alluvial
Relating to and/or sand deposited by flowing water.
Allyl
A molecular fragment derived by removing a methyl hydrogen from propene.
Allyl Alcohol
Used in the manufacture of resins and many pharmaceuticals this is a colourless pungent liquid.
Allyl Aldehyde
Alternative name for Acrolein.
Almond Artificial Essential Oil
Alternative name for Benzaldehyde.
AlN
Chemical formula for Aluminium Nitride.
Alnico Magnet
A magnet using aluminum, nickel, and cobalt in its construction.
Alpakka
A nickel silver made from 65% copper, 22% zinc, 13% nickel.

Alpha
The first letter of the Greek alphabet.
Alpha Iron
The body-centered cubic (BCC) form of pure iron, stable below 910C.
Alpha Particle
The nucleus of helium consisting of two protons and two neutrons.
Alpha Radiation
A stream of alpha particles. Alpha rays rapidly dissipate their energy as they pass through materials, and are far less penetrating than beta particles and gamma rays.
Alpha Risk
The probability of rejecting a null hypothesis when it is true. It is the probability of making a Type I error.
Alpha Rockwell Hardness
Index of the resistance of a plastic to surface penetration by a specified indenter under specified load applied with a Rockwell hardness tester.
Alpha Stirling Engine
A striling engine that has two separate power pistons, one hot and one cold.
Alphabetics
The science of representing spoken sounds by letters.
Alphametic
A cryptarithm in which the letters, which represent distinct digits, form related words or meaningful phrases.
Alphanumeric
A character set that contains both letters and digits.
Alternate Exterior Angles
Exterior angles on alternate sides of the transversal ie not on the same parallel line.
Alternate Interior Angles
Interior angles on alternate sides of the transversal ie not on the same parallel line.
Alternating Copolymer
A polymer, composed of two different repeating mers, in which the different mer units systematically alternate positions along the molecular chain.
Alternating Current
An electric current whose direction changes direction with a frequency independent of circuit components.
Alternative Energy
Energy derived from non-fossil-fuel sources.
Alternative Fuels
Substitutes for traditional liquid, oil-derived motor vehicle fuels like gasoline and diesel.
Alternator
An electric generator for producing alternating current.
Altimeter
An instrument for measuring height above a reference datum.
Altitude
Height in space of an object or point relative to sea level or ground level.
Altitude Acclimatization
Physiological adaptation to reduced atmospheric and oxygen pressure.
Altitude Chamber
A chamber that can simulate conditions at different altitudes.
Altitude of a Conic Solid
The length of a segment whose endpoints are the vertex and a point on the plane of the base that is perpendicular to the plane of the base.
Altitude of a Cylindric Solid
The distance between the planes of the bases.
Altitude of a Trapezoid
The distance between the bases of a trapeziod.
Altitude of a Triangle
The perpendicular segment from a vertex to the line containing the opposite side of a triangle.
Altitude Sickness
Sickness brought on by exposure to reduced oxygen tension and barometric pressure.
Altitude Wind Tunnel
A wind tunnel in which the air pressure, temperature, and humidity can be varied to simulate conditions at different altitudes.
Altocumulus
Composed of flattened, thick, gray, globular masses, this middle cloud genus is primarily made of water droplets.
Altocumulus Castellanus
A middle cloud with vertical development that forms from altocumulus clouds.
Altostratus
Middle cloud genus is composed of water droplets, and sometimes ice crystals.
Alumel
Trade name for an alloy of nickel with up to 5% aluminium, manganese and silicon, used with chromel in K-type thermocouples.

Aluminium
Basis for a number of alloys.
Aluminium 1000 series
High purity aluminium with excellent corrosion resistance, high thermal conductivity, high electrical conductivity, excellent workability, but the downside is low mechanical properties

Aluminium 1050
Part of the 1000 series. This particular alloy is 99.5% pure aluminium.

Aluminium 1060
Part of the 1000 series. This particular alloy is 99.6% pure aluminium.

Aluminium 1100
Part of the 1000 series. This particular alloy is 99.0% pure aluminium.

Aluminium 1199
Part of the 1000 series. This particular alloy is 99.99% pure aluminium.

Aluminium 2000 series
The principal alloying element is copper and can be heat treated to achieve mechanical properties that can exceed mild steel. The downsides are: solution heat treatment required to get optimum properties, corrosion resistance not as good as other aluminium alloys, tend to be brittle and exhibit poorer corrosion resistance than other alloy series.

Aluminium 2014
Among the strongest available aluminium alloys, as well as having high hardness. Difficult to weld, as it is subject to cracking.

Aluminium 2024
Aluminium alloy, with copper as the primary alloying element.

Aluminium 3000 series
The principal alloying element is manganese - up to 1.5%, moderate strength, higher manganese alloys have good machinability, particularly resistant to pitting corrosion.

Aluminium 3003
Commercially pure aluminum with the addition of manganese that increases the strength. 3003 has excellent corrosion resistance and workability.

Aluminium 4000 series
The principal alloying element is silicon, in significant amounts it lowers the melting point. Most alloys non-heat treatable and good casting qualities.

Aluminium 5000 series
The principal alloying element is magnesium, alloys with high magnesium and manganese result in high strength but non-heat treatable, good welding characteristics, anodizes well and good resistance to corrosion even in marine environments. The downsides are: limited cold working and lower safe operating temperatures due to magnesium content.

Aluminium 5005
Aluminium alloy with good resistance to atmospheric corrosion.

Aluminium 5052
Aluminium alloy, primarily alloyed with magnesium and chromium.

Aluminium 5083
Aluminium alloy with magnesium and traces of manganese and chromium. It is highly resistant to attack by seawater and industrial chemicals. Alloy 5083 retains exceptional strength after welding. It has the highest strength of the non-heat treatable alloys, but is not recommended for use in temperatures in excess of 65°C.

Aluminium 5086
Primarily alloyed with magnesium. It is strengthened by strain hardening, or cold mechanical working of the material. Since heat treatment doesn′t strongly affect the strength, 5086 can be readily welded and retain most of its mechanical strength.

Aluminium 6000 series
The principal alloys silicon and magnesium. This series is heat treatable, has good formability, good corrosion resistance and medium strength. Relatively easy to roll extrude and forge.

Aluminium 6061
A precipitation hardening aluminium alloy, containing magnesium and silicon as its major alloying elements. Good mechanical properties and exhibits good weldability. It is one of the most common alloys of aluminium for general purpose use.

Aluminium 6063
An aluminium alloy, with magnesium and silicon as the alloying elements. Generally good mechanical properties and is heat treatable and weldable.

Aluminium 6066
An aluminium alloy used in forgings and extrusion for welded structures.

Aluminium 7000 series
The principal alloy is Zinc. The addition of magnesium results in heat-treatable and very high strength and sometimes other elements added such as copper and chromium.

Aluminium 7005
Similar physical properties to 6061 aluminium alloy, except it has a higher density.

Aluminium 7075
An aluminium alloy, with zinc as the primary alloying element. It is strong, with a strength comparable to many steels, and has good fatigue strength and average machinability, but has less resistance to corrosion than many other Al alloys. Its relatively high cost limits its use to applications where cheaper alloys are not suitable.

Aluminium 7079
A high strength aluminium alloy used in the aircraft industry.

Aluminium 8000 series
This series of aluminium is mainly used for lithium alloys. May contain tin, iron or silicon. Can be rolled into thin sheets.

Aluminium Alloys
Aluminum containing specified quantities of alloying elements added to obtain the necessary mechanical and physical properties.
Aluminium Brazing
Aluminium with a thin outer high silicon coating may be brazed.
Aluminium Bromide

Al2Br6

White or very pale yellow crystalline solid.

Aluminium Bronze
A copper-aluminum alloy with high tensile strength and resistance to corrosion.

Aluminium Chloride
A chloride used as a wood preservative or catalyst.

Aluminium Fluoride

AlF3

White crystalline solid.

Aluminium Hexabromide
Alternative name for Aluminium Bromide.
Aluminium Hexachloride
Alternative name for Aluminium Chloride.
Aluminium Hexaiodide
Alternative name for Aluminium Iodide.
Aluminium Hydride

AlH3

White crystalline solid.

Aluminium Hydroxide
White crystalline compound that occurs naturally as the mineral gibbsite.

Aluminium Iodide

Al2I6

White solid.

Aluminium Nitride

AlN

Bluish white crystalline solid.

Aluminium Oxide

Al2O3

Alminium oxide is the most widely used oxide ceramic, either in pure form or as raw material to be mixed with other oxides.

Aluminium Production
Aluminum metal is produced by electrolysis of aluminum oxide dissolved in a high-temperature molten-salt electrolyte.
Aluminium Sulphide

Al2S3

Yellow or yellow grey powder.

Aluminium Temper
The heat treatment and coding as applied to aluminium.
Aluminium Tribromide
Alternative name for Aluminium Bromide.
Aluminium Trichloride
Alternative name for Aluminium Chloride.
Aluminium Triiodide
Alternative name for Aluminium Iodide.
Aluminizing
Formation of an aluminum or aluminum-alloy coating on a metal by hot dipping, hot spraying or diffusion.
Alvarez, Luis Walter
American physicist who produced free protons with a particle accelerator.