Ex

exa
Prefix representing a multiplication of 1018
exbibyte
Equal to two to the power of sixty bytes.
Excentre
The centre of an excircle.
Excircle
An escribed circle of a triangle.
Excitation
Excitation is an external force or motion (or other input) applied to a system that causes the system to respond in some way.
Excitation Voltage
The supply voltage required to activate a circuit.
Excited State
Atom with an electron in a higher energy level than it normally occupies.
Excitotoxin
An excitotoxin is a toxic molecule that stimulates nerve cells so much that they are damaged or killed.
Exclusion Principle
No two electrons can have the same set of quantum numbers. This statement also applies to protons, neutrons, and other baryons.
Exclusive Or
One or the other, but not both.
Exclusive Or Gate
Logic element that features two inputs. The output will be 1 only when one or the other (but not both) is logic 1. In all other cases the output is 0.
Excretion
The removal of waste substances from living things.
Exergonic
Refers to a reaction for which the free energy of the system decreases.
Exhaust
An exhaust system of an internal combustion engine performs a number of functions.
Exhaust Cam
The cam that controls the operation of the exhaust valve.
Exhaust Catalyst
A catalytic converter is known to have two distinct acoustic effects: Reactive Effect and Resistive Effect.
Exhaust Catalyst Thermal Management
An exhaust catalyst runs at a high temperature internally and has a high surface temperature that also needs to be accounted for when packaging.
Exhaust Downpipe
The pipe used to route the exhaust flow from the manifold or turbo to the underbody of the vehicle.
Exhaust Gas Oxygen
The concentration of oxygen in the exhaust of an engine is used in closed-loop fuel control systems to indicate rich or lean air fuel ratios.
Exhaust Gas Recirculation
A portion of exhaust is introduced into the intake of an engine primarily for NOx reduction.
Exhaust Gases
Products of combustion which are discharged from the cylinder after doing work on the piston.
Exhaust Injector
A feedwater injector that economizes on steam consumption by using waste steam, such as engine exhaust.
Exhaust Manifold
The pipe that collects the burnt gases as they are expelled from the cylinders.
Exhaust Noise
The exhaust system of an internal combustion engine has a number of functions, one of which is to reduce the noise of the waste gases as they are expelled from the engine to the atmosphere.
Exhaust Pipe
Piping through which exhaust gases from an engine pass out to the atmosphere.
Exhaust Silencer
Acoustic filter elements used to reduce sound pressure levels in an exhaust system.
Exhaust System
A collection of pipes, silencers, sensors and catalysts or filters that make a system to channel the waste exhaust gases away from an internal combustion engine.
Exhaust Tailpipe
The final pipe that the exhaust gas passes through before mixing with the atmosphere.
Exhaust Valve
The valve through which the burnt gases are allowed to pass out to the exhaust manifold.
Exobiology
The study of biological processes that have or could have evolved away from the Earth.
Exocytosis
The fusion of an intracellular vesicle with the plasma membrane, releasing the vesicle contents to the extracellular space.
Exon
The segment of a eukaryotic gene that is transcribed into a protein or incorporated into the structure of an RNA.
Exonuclease
An enzyme that hydrolyzes phosphodiester bonds that are in the terminal positions of a nucleic acid.
Exosphere
This region is considered the very outer limits of the earth's atmosphere.
Exothermic
Reaction that gives off heat to the environment.
Expansion
An increase in size.
Expansion Chamber
The expansion chamber can be considered as a simple low pass filter.
Expansion Period
The portion of the power stroke during which the combustion gases expand from the movement of the piston and thus do work.
Expansion Tube Tunnel
A wind tunnel for conducting tests at hypervelocity.
Experiment
A process or study that results in the collection of data, the outcome of which is unknown.
Experimental Probability
The chances of something happening, based on repeated testing and observing results.
Experimental Yield
The measured amount of product produced in a chemical reaction.
Expert System
Encapsulates the specialist knowledge gained from a human expert and applies that knowledge automatically to make decisions.
Explosion
The sudden production of a large quantity of gas, usually hot, from a much smaller amount of a gas, liquid, or solid.
Explosion Proof Enclosure
A totally enclosed enclosure, which is constructed to withstand an explosion of a specified gas, vapor or dust which, may occur within it.
Explosive Decompression
A very rapid reduction of air pressure inside a cabin, coming to a new static condition of balance with the external pressure.
Exponent
In the expression am, m is the exponent and a is the base. am is the mth power of a. If this is set equal to y (y=am) then this is called an exponential function.
Exponential Constant
The base of natural (Napierian) logarithms e = 2.718281...
Exponential Form of Complex Numbers
Exponential expression of complex numbers.
Exponential Function
The function f(x)=ex.
Exponential Function to Base a
The function f(x)=ax.
Exponential Smoothing
A statistical technique commonly used to forecast time series data or to smooth the values on a control chart.
Exponential Window
A special windowing function for minimizing leakage in lightly damped structures that is used in impact testing.
Exposed Concrete Aggregate
A concrete surface with the aggregate exposed, formed by applying a retarder to the surface before the concrete has set, and subsequently removing the cement paste to the desired depth.
Exposed Hinge
Hinges that show on the outside when the door is closed.
Expression
A validated series of variables, constants, and functions that can be connected by operating symbols to describe a desired computation.
Expulsion Fuse
A vented fuse or fuse unit in which the expulsion effect of gases produced by the arc and the lining of the fuse holder, either alone or aided by a spring, extinguishes the arc.
Exradius
The radius of an escribed circle.
Extended Source
An extended source of radiation can be resolved into a geometrical image in contrast with a point source of radiation, which cannot be resolved into a geometrical image.
Extensible Markup Language
Better known in the abbreviated form as XML. XML is a markup language much like HTML.
Extensive Properties
Properties which are dependent on the amount of the substance.
Extensometer
A test apparatus for indicating the deformation of metal while it is subjected to stress.
Exterior Noise
Noise produced by a vehicle and radiating to its surroundings.
External Combustion Engine
An engine that burns the fuel outside of the engine, such as a steam engine or stirling engine.
External Force
A surface force or body force acting on an object.
External Meatus
The ear canal terminated by the eardrum.
External Thread
A screw thread which is formed on an external cylinder,e.g. bolts, screws, studs.
External Trigger
A voltage pulse from an external source that triggers an event such as A/D conversion.
Externally Excited Meter
A term used to describe meters that get their power from the circuit to which they are connected.
Externally Sychronized Radar
A radar system in which timing pulses are generated by a master oscillator external to the transmitter.
Extinct Volcano
A volcano that is not presently erupting and is not likely to do so for a very long time in the future.
Extinction
The attenuation of light as it passes through a medium.
Extinction Potential
The potential at which ionization of the gas within a gas-filled tube ceases and conduction stops.
Extragalactic
Outside the Milky Way.
Extraterrestrial
A term used to describe anything which does not originate on the Earth.
Extreme Pressure Additive
Lubricant additive that prevents sliding metal surfaces from seizing under conditions of extreme pressure.
Extreme Pressure Lubricants
Lubricants that impart to rubbing surfaces the ability to carry appreciably greater loads than would be possible with ordinary lubricants without excessive wear or damage.
Extreme Ultraviolet
A portion of the electromagnetic spectrum from approximately 100 to 1000 angstroms.
Extremely High Frequency
The portion of the electromagnetic spectrum between 30 GHz and 300 GHz.
Extremely Low Frequency
That portion of the radio frequency spectrum from 30 to 3000 hertz.
Extrinsic Semiconductor
A semi-conducting material for hich the electrical behavior is determined by impurities.
Extruded
A material that has been shaped by forcing through a die.
Extrusion
A forming technique whereby a material is forced, by compression, through a die orifice.