Germanium is a silvery white brittle metalloid member of the carbon group of elements. Its physical properties being similar to those of silicon.
Gear Cutter
Rotating cutting tool used in a mill to cut the teeth of a gear.
Gear Design
Fundamental parameters used in describing gears.
Gear Mesh Frequency
A potential vibration frequency on any machine that contains gears; equal to the number of teeth multiplied by the rotational frequency of the gear.
Gear Noise
Gear noise such as whine are generated by meshing gears due to the vibration caused by failure of the rolling action between the mating teeth.
Gear Oil
A high-quality oil with good oxidation stability, load-carrying capacity, rust protection, and resistance to foaming.
Gear Pump
Uses the meshing of gears to pump fluid by displacement.
A mechanical device that provides a torque-speed conversion between an input and output shaft.
Wheels with teeth around the circumference that mesh to transfer rotation between the two at the ratio of the radius of the pitch circle.
Chemical formula for Germanium II Chloride.
Chemical formula for Germanium IV Chloride.
Chemical formula for Germane.
Geiger Counter
A radiation detector consisting of two electrodes with a low-pressure gas in between.
Geiger, Johannes
Helped to develop first successful counter of alpha particles.
A sol in which the solid particles fuse or entangle to produce a rigid or semirigid mixture.
Gel Cell
A technique for sealed lead-acid batteries. The electrolyte solution is in a gel form, usually silica gel, instead of plain liquid.
Gel Filtration
A chromatographic procedure for the separation of a mixture of molecules on the basis of size.
Part of a chromosome found inside the cells of living organisms.
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General Circulation
The large scale motions of the atmosphere and the ocean as a consequence of differential heating on a rotating Earth, aiming to restore the energy balance of the system through transport of heat and momentum.
General Conversions
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General Purpose Interface Bus
More commonly abbreviated as GPIB.
General Theory of Relativity
An extension of the special theory of relativity to include the concept of gravity.
General Weblinks
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Generalised Coordinates
The minimum number of independent coordinates necessary to completely describe a systems position constitutes a set of generalized coordinates.
Generating Capacity
The maximum amount of electric power produced by a generator.
A machine that converts mechanical energy to electrical energy by applying the principle of magnetic induction.
Generator Rule
Also known as the Fleming′s Right Hand Rule this is a way of determining the direction of the induced emf of a conductor moving in a magnetic field.
Generator Set
A generating system comprising a combustion engine driving an electrical generator.
The bent line-segment or figure that replaces the initiator at each iteration of a fractal.
Genetic Algorithm
A type of optimization algorithm that uses Darwinian principles to evolve a solution to a mathematical model based on survival of the fittest.
Genetic Code
The set of triplet code words in mRNA or DNA, coding for the amino acids of proteins.
Genetic Engineering
A man-made method of altering the genes to change the characteristics of an organism.
Genetic Information
The hereditary information contained in a sequence of nucleotide bases.
Genetic Map
A diagram showing the position of specific genes along a chromosome relative to markers.
The complete set of genetic information of an organism.
Genomic Library
A random collection of cloned DNA fragments designed to include all or most of the genome of a given organism.
The genetic information of an organism, as distinct from its physical expression (phenotype).
Abbreviation of Generator Set.
Gent′s Saw
A smaller version of a dovetail saw with a straight round handle.
Chemical formula for Germanium Monoxide.
Chemical formula for Germanium IV Oxide.
A flat board into which nails have been driven in a regular rectangular pattern.
Geocentric Model
A model of the Universe with the Earth at its center.
The study of materials and chemical reactions in rocks, minerals, magma, seawater, and soil.
The outermost layer of the Earth′s neutral atmosphere.
The arc on a surface of shortest length joining two given points.
Geodesic Dome
A dome composed of short, straight pieces joined to form triangles; invented by Buckminster Fuller.
The study of the shape of the Earth, e.g. its deviations from an exact sphere.
Geodetic Coordinates
A system of geographic position referencing. Angular measurements of latitude and longitude are projected onto a well-defined reference ellipsoid that approximates the earth′s irregular shape.
Geographical Mile
The length of 1 minute of arc of the equator.
Geological Timescale
The ages of the history of planet earth from the Pleistocene to the Precambrian era.
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Geomagnetic Field
The magnetic field observed in and around the Earth.
Geometric Electrode Area
The surface area of an electrode calculated from its geometrical dimensions.
Geometric Isomer
Molecules that have the same molecular formula and bond connections, but distinctly different shapes.
Geometric Mean
A statistic calculated by multiplying n data values together and taking the n-th root of the result.
Geometric Multiplicity of an Eigenvalue
For an eigenvalue c of a matrix A this is the dimension of the eigenspace of c.
Geometric Optics
That branch of optics dealing with the tracing of ray paths through optical systems.
Geometric Position
True position.
Geometric Progression
A sequence in which the ratio of each term to the preceding term is a given constant.
Geometric Scattering
Acoustic scattering in which the wavelength of the sound used is much smaller than the size of object causing the scattering.
Geometric Sequence
A set where each element is a multiple of the previous element.
Geometric Series
A series in which the ratio of each term to the preceding term is a given constant.
Geometric Solid
The bounding surface of a 3-dimensional portion of space.
Geometric Volume
The volumes of a material calculated from measurements of its physical dimensions.
Geometrized Units
A system of units whereby certain fundamental constants are set to unity.
The branch of mathematics that deals with the nature of space and the size, shape, and other properties of figures as well as the transformations that preserve these properties.
Geometry Books
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Geometry Calculations
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Geometry Conversions
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Geometry Weblinks
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Prevailing style of English architecture during the reigns of George I, II, and III 1714 to 1820.
A satellite orbit traveling from west to east at speeds that allow it to remain fixed over a given place on the earth′s equator at approximately 22,300 miles in altitude. A geostationary satellite makes one revolution in 24 hours, synchronous with the earth′s rotation.
Geotechnical Engineer
An engineer who evaluates and stabilizes foundations for buildings, roads, and other structures.
Geothermal Energy
Energy made by using underground steam; the steam produces electricity.
Geothermal Gradient
The rate at which temperature increases with depth below the surface.
Movement of a plant in response to gravity.


A clear to pale-yellow oil that is insoluble in water, but soluble in most common organic solvents.

Gergonne Point
In a triangle, the lines from the vertices to the points of contact of the opposite sides with the inscribed circle meet in a point called the Gergonne point.
German Silver
This describes a number of alloys that contain copper (25 to 50%), zinc (10 to 35%) and nickel (5 to 35%) within the limits given.


Used in the semiconductor industry for the epitaxial growth of germanium.

Another name for Germanium IV Oxide.
A silvery white brittle metalloid member of the carbon group of elements. Its physical properties being similar to those of silicon.
Germanium Chloride
Alternative name for Germanium IV Chloride.
Germanium Dichloride
Alternative name for Germanium II Chloride.
Germanium Dioxide
Another name for Germanium IV Oxide.
Germanium Disulphide
Alternative name for Germanium IV Sulphide.
Germanium II Chloride


White-pale yellow solid which on warming gives brown germanium monoxide.

Germanium II Selenide


Black crystalline powder having orthorhombic crystal symmetry.

Germanium IV Chloride


Colourless liquid used as an intermediate in the production of purified germanium metal.

Germanium IV Oxide


Refractive index and optical dispersion properties make it useful as an optical material for wide-angle lenses and in optical microscope objective lenses.

Germanium IV Sulphide


White crystalline solid.

Germanium Monoxide


Prepared as a yellow sublimate at 1000C by reacting GeO2 with Ge metal.

Germanium Selenide
Alternative name for Germanium II Selenide.
Germanium Telluride


Shows semimetallic conduction and ferroelectric behaviour.

Germanium Tetrachloride
Alternative name for Germanium IV Chloride.
Germanium Tetrahydride
Alternative name for Germane.
Alternative name for Germane.
The growth of a new plant from a seed.
Chemical formula for Germanium IV Sulphide.
Chemical formula for Germanium II Selenide.
Gestation Period
The length of gestation, the time from conception to birth. For humans this is 266 days.
Chemical formula for Germanium Telluride.
An alkali metal introduced into a vacuum tube during manufacture.
Abbreviation of Giga electron Volt.
Boiling hot water that is violently ejected from underground when some of the water is converted to steam.