Cobalt is a hard, grey metal which is ferromagnetic.
Chemical formula for Carbon Monoxide.
Chemical formula for Carbon Dioxide.
CO2 Equivalent
The amount of carbon dioxide that would cause the same integrated radiative emission as the emitted amount of greenhouse gases.
CO2 Laser
Abbreviation of Carbon Dioxide Laser.
Chemical formula for Cobalt III Oxide.
Coach Bolt
A small rounded head with a square section under the head designed to stop the bolt rotating.
The vehicle body - especially the comfort and luxury appointments as distinguished from the operational chassis.
A fossil fuel which is made mostly of carbon. It is formed from plants that grew around 150 million years ago.

Coal Gas
Obtained when coal is heated in the absence of air at about 1300°C in either gas ovens or gas-making retorts. A colourless gas with a characteristic odour. It is lighter than air and burns with a long smoky flame.

Coal Tar
A dark brown to black cementitious material produced by the destructive distillation of bituminous coal.

Coanda Effect
The effect that indicates that a fluid tends to flow along a surface, rather than flow through free space.
Coarse Pearlite
Pearlite for which the alternating ferrite and cementite layers are relatively thick.
Coaxial Cable
A round cable with a central conductor and screening around with a insulating medium between.
Coaxial Line
A type of transmission line that contains two concentric conductors.
A hard, grey metal which is ferromagnetic.
Cobalt Dichloride
Alternative name for Cobalt II Chloride.
Cobalt II Bromide


Green crystals, used as a catalyst in the oxidation of some organic compounds.

Cobalt II Chloride


Used as an indicator for water as there is a dramatic colour change from CoCl2 which is blue to CoCl2·6H2O which is a deep rose colour.

Cobalt II Nitrate


A red crystalline solid with high solubility of cobalt nitrate makes it a common source of cobalt in metal-organic frameworks and polymers. Deliquescent in moist air.

Cobalt II Oxide


Olive green to red crystals or greyish or black powder used in ceramics to create blue coloured glazes.

Cobalt III Oxide


A black substance obtained by adding cobalt II nitrate to an aqueous solution of sodium hypochlorite.

Cobalt Monoxide
Alternative name for Cobalt II Oxide.
Cobalt Sesquioxide
Alternative name for Cobalt III Oxide.
Cobalt Trioxide
Alternative name for Cobalt III Oxide.
Cobaltic Oxide
Alternative name for Cobalt III Oxide.
Cobaltous Chloride
Alternative name for Cobalt II Chloride.
Cobaltous Monoxide
Alternative name for Cobalt II Oxide.
Cobaltous Nitrate
Alternative name for Cobalt II Nitrate.
Cobaltous Oxide
Alternative name for Cobalt II Oxide.
COmmon Business Oriented Language - A coding system designed to facilitate the digital programming of business-oriented problems.
Chemical formula for Cobalt II Bromide.
Occupying the same portion of the frequency spectrum.
A snail shaped mechanism in the inner ear that contain hair cells of basilar membrane that vibrate to aid in frequency recognition.
Enclosed or semi enclosed area for the pilot and co-pilot of an aeroplane.
Cocktail Party Effect
This is the ability of the human hearing system to effectively reject spurious noises and allow the hearing to "home in" on the sound that is arriving from a particular direction.
Chemical formula for Cobalt II Chloride.
Cured and simultaneously bonded to another prepared surface.
When used as a verb, code means to write a program. As a noun, code refers to the binary instructions of a program.
Acronym for compressor/decompressor.
Organic bases in sets of three that form the genetic code.
A coefficient is a constant multiplicative factor of a certain object.
Coefficient of Coupling
An expression of the extent to which two inductors are coupled by magnetic lines of force.
Coefficient of Elasticity
An alternate term for modulus of elasticity or Young′s Modulus.
Coefficient of Friction
The number obtained by dividing the friction force resisting motion between two bodies by the normal force pressing the bodies together.
Coefficient of Performance
The ratio of cooling or heating to energy consumption.
Coefficient of Thermal Expansion
The constant value or factor of expansion of a material for a given increase in temperature, divided by the length of the material. This is different for each material.
An organic cofactor required for the action of certain enzymes.
Coercive Force
Magnetizing force needed to reduce residual magnetism in a material to zero.
An inorganic ion or a coenzyme required for enzyme activity.
A sunken panel in a ceiling.
A temporary dam built to divert a river around a construction site so the dam can be built on dry ground.
A tooth in the rim of a wheel or a gear tooth in a gear wheel.
A term used to describe the combination of different thermodynamic cycles for the purpose of increasing all-over cycle efficiency.
Non-uniform angular velocity.
The processes of human or animal thought. The acquisition, understanding, representation and manipulation of knowledge.
Cognitive Science
The study of thought processes in animals and machines.
This gives a measure of the linear dependence between signal A and B.
A property of two or more sources of waves that have the same wavelength and maintain constant phase differences.
Coherent Anti-Stokes Raman Scattering
A phenomenon observed in the scattering of light as it passes through a transparent medium. The light undergoes a change in frequency and a random alteration in phase due to a change in rotational or vibrational energy of the scattering molecules.
Attraction between like molecules.
Cohesive Force
The attractive force exerted on a liquid molecule by the neighbouring liquid molecules.
Cohesive Strength
Theoretical stress that causes fracture in tensile test if material exhibits no plastic deformation.
An inductive device made by looping turns of wire around a core.
Coil Over Shock
Standard assembly of spring and damper, where spring perches are at each end of damper.
Coil Spring
A steel spiral spring used to isolate a vehicle from the road.
Coin Cell
A miniature non-rechargeable battery, in the shape and size of a small coin used to power small electronic devices.
The sound radiation efficiency of a plate is dependant upon the coupling of sound waves in the air and flexural waves (vibration) in the plate. Optimum efficiency (maximum energy transfer from vibration to sound or visa versa) is achieved when the plate is vibrated such that the wavelength of flexural waves in the plate is equal to the wavelength of acoustic waves in the air.
A hard, dry substance containing carbon that is produced by heating bituminous coal to a very high temperature in the absence of air.

The undesirable accumulation of carbon deposits in the internal combustion engine or in a refinery plant.
Cold Air Funnel
Funnel clouds, usually short-lived, that develop from relatively small showers or thunderstorms when the air aloft is very in cold.
Cold Alignment
The machine condition in which alignment procedures are normally performed, ie cold.
Cold Cathode Tube
A gas-filled electron tube that conducts without the use of filaments.
Cold Chisel
Tool made of tempered steel used for cutting ′cold′ metals.
Cold Core Thunderstorms
Thunderstorms formed primarily due to steep lapse rates, especially when very cold air aloft overlies warmer surface air.
Cold Cranking Amps
The current required by the starter motor to crank an engine in cold weather.
Cold Drawing
This is a process for finishing a hot rolled rod or bar at room temperature by pulling it through the hole of a die of the same shape but smaller in size.
Cold Filter Plugging Point
A measure of the ability of a diesel fuel to operate under cold weather conditions and is defined as the lowest temperature at which diesel fuel will pass through a fine wire mesh screen of the test apparatus.
Cold Junction
The reference junction of a thermocouple which is kept at a constant temperature.
Cold Junction Compensation
The means to compensate for the ambient temperature in a thermocouple measurement circuit.
Cold Metal Spraying
Involves injecting microscopic powdered particles of metal or other solids into a supersonic jet of rapidly expanding gas and shooting them at the surface.
Cold Plasma Model
A model of a plasma in which the temperature is neglected.
Cold Rolled Steel
Steel that has been rolled to accurate size and smooth finish when made. In contrast, hot-rolled steel may have a rough, pitted surface and slag inclusion.
Cold Rolling
The cold working of hot rolled material by passing it between power driven rolls.
Cold Stuck Piston Ring
A piston ring that is stuck when the piston and ring are at room temperature, but inspection shows that it was free during engine operation.
Cold Treatment
A heat treat process which converts unstable retained Austenite into stable untempered Martensite.
Cold Working
The plastic deformation of a metal at a temperature below that at which it re-crystallizes.
Colebrook Equation
Used to calculate the friction coefficients in different kinds of fluid flows - air ventilation ducts, pipes and tubes with water or oil, compressed air and much more.
In the same line.
Colinear Array
An array with all the elements in a straight line. Maximum radiation is perpendicular to the axis of the elements.
The most abundant protein in mammals.
Collapsible Core
A metal insert made in two or more pieces to permit withdrawal from an undercut mould surface.
Collateral Points
North-East, North-West, South-East and South-West are known as the Collateral Points.
Collective Pitch Control
Used to change simultaneously the pitch of all of a helicopter rotor′s blades to permit ascent or descent.
One terminal of a transistor.
Collector Injection Modulator
The transistor equivalent of a plate modulator.
A precision work holding chuck which centres finished round stock automatically when tightened.
An accelerator in which two beams traveling in opposite directions are steered together
Colligative Properties
Properties of a solution that depend only on the number of particles dissolved in it, not the properties of the particles themselves.
Collimated Light
Light rays that are parallel.
The alignment of the direction of the photons, so the beam of radiation can be directed at a well-defined part of a target material.
A mechanical device installed along the trajectory of a beam to reduce the size of the beam.
Points are said to be collinear if they all lie on the same line.
An encounter between two ojects that changes their existing momentum and energy conditions.
Collision Density
The rate at which collisions are occurring per unit volume per unit time.
Collision Diameter
The distance between the centres of two colliding molecules when at their closest point of approach.
Collision Frequency
The average number of collisions that a molecule undergoes each second.
Collision Theory
A theory that explains reaction rates in terms of collisions between reactant molecules.
A heterogeneous mixture composed of tiny particles suspended in another material.
The main part of the large intestine. It absorbs water from food.
A row of columns, usually equidistant.
A quality of light, depending on its wavelength. Spectral colour of an emission of light is its place in the rainbow spectrum.
Colour Charge
The charge associated with strong interactions.
Colour Temperature
The colour of a piece of steel may be used as a guide to it's temperature. These are particulalrly useful when hardening or tempering steel.
Property of quarks associated with their binding with gluons.
A listening term. A visual analog. A "coloured" sound characteristic adds something not in the original sound. The colouration may be euphonically pleasant, but it is not as accurate as the original signal.
A method for chemical analysis that relates colour intensity to the concentration of analyte.
This is a method of plotting noise or vibration versus engine speed and frequency simultaneously.
A name sometimes given to Niobium, a platinum-gray, ductile metal with brilliant luster that is used in alloys, especially stainless steels.
A pillar, usually of round cross-section but sometimes square or octagonal, used to support the roof of a building, porch, or portico.
Column Chromatography
A method for separating mixtures.
Column Space of a Matrix
The subspace spanned by the columns of the matrix considered as a set of vectors.
Columnar Structure
Coarse structure of parallel columns of grains.
A spherical cloud of material surrounding the head of a comet.
Comb Filter
A distortion produced by combining an electrical or acoustical signal with a delayed replica of itself.
Combination Array
An array system that uses the characteristics of more than one array.
Combination Electrode
An assembly that combines an ion-selective electrode and a reference electrode in one physical structure.
Combination Reaction
A reaction in which two or more substances are chemically bonded together to produce a product.
Combination Spanner
A flat wrench with a hex ring at one end and an open end at the other.
Combination Square
A drafting and layout tool combining a square, level, protractor, and centre head.
Combinational Logic
Logic circuits whose outputs depend only on the present logic inputs.
A combination is the set itself without reference to order.
Combined Cooling Heat and Power
Utilises the waste heat from a fuel cell or engine with absorption chillers to provide air conditioning and hot or cold water alongside electricity.
Combined Cycle Gas Turbine
A unit whereby electricity is generated by a gas powered turbine and also a second turbine.
Combined Heat and Power
Electrical power generator set where the waste heat is used to heat water for building heat supply or for industrial processes.
Combined Steam Gas Plant
A gas turbine combined with a steam plant in order to utilize the waste heat and so improve overall efficiency.
Combined Water and Power
Similar to CHP, but in this instance the waste heat is used to produce potable water.
Combined-Cycle Engine
Engine concepts using some combination of air-breathing and rocket components which are integrated into a single propulsion system.
Substance that can easily be set on fire and that will burn readily or quickly. Flammable.
A chemical reaction between a fuel and an oxidizing agent that produces heat.
Combustion Chamber
The space above the piston in which the fuel-air mixture starts to burn in an internal combustion engine.
Combustion Chamber Recess
The area where combustion occurs in a Wankel Engine.
Combustion Engine
An engine that uses the heat from the combustion of a fuel to operate, fundamentally split into Internal and External combustion engines.
Combustion Pressure
The pressure created during the combustion of the air fuel mixture in the cylinder.
Combustion Reaction
The vigorous and exothermic reaction that takes place between certain substances, particularly organic compounds, and oxygen.
Combustion Residue
Carbon and other deposits resulting from combustion.
A chunk of frozen gasses, ice, and rocky debris that orbits the Sun.
Comma Cloud
A feature seen on satellite images with a distinctive comma-shape.
Common Base Connection
Same as ground base connection. A mode of operation of a transistor in which the base is common to both the input and output circuits and is usually earthed.
Common Collector Connection
A mode of operation of a transistor in which the collector is common to both the input and the output circuits and is usually connected to one of the power rails.
Common Denominator
A multiple shared by the denominators of two or more fractions.
Common Emitter Connection
A mode of operation for a transistor in which the emitter is common to the input and output circuits. The base is the input terminal and the collector is the output terminal.
Common Era
Replaces AD especially in countries where Christianity is not a dominant religion.
Common Fraction
A fraction whose numerator is an integer of smaller value than its denominator.
Common Logarithm
Logarithm in which the base is 10.
Common Mode Failure Analysis
CMFA evaluates the impact of coincidental failure in different parts of a complete system.
Common Rail
A pipe or header from which branch lines lead to each of the fuel valves in the different cylinder heads of a diesel engine.
Common Return
return conductor common to two or more circuits.
Common Salt
Sodium Chloride.
Common-Mode Range
The input range over which a circuit can handle a common-mode signal.
Common-Mode Rejection Ratio
The ability of the differential amplifier to obtain the difference between the + and - inputs whilst rejecting the signal common to both.
Common-Mode Signal
A signal applied simultaneously to both inputs of a differential amplifier.
Community Noise Criteria
There are a number of different noise criteria measurements used by local authorities to determine noise levels in the community.
Community Noise Equivalent Level
There are a number of different noise criteria measurements used by local authorities to determine noise levels in the community.
Describes an operator that gives the same result irrespective of the order of arguments.
An electrical switch that periodically reverses the current direction in an electric motor or electrical generator.
Compact Disc
An optical disc designed to store digitally 74 minutes of stereo audio data.
A combination of a compressor at one point in a communication path for reducing the volume range of signals, followed by an expander at another point for restoring the original volume range.
A combination of a compressor at one point in a communication path for reducing the volume range of signals, followed by an expander at another point for restoring the original volume range.
The earliest-known compass dates from China, during the Han Dynasty (2nd century BC - 2nd century AD).
Compass Saw
A handsaw with a thin blade designed for cutting holes in boards with a drilled hole as a starting point.
Compensation Windings
Windings embedded in slots in pole pieces, connected in series with the armature, whose magnetic field opposes the armature field and cancels armature reaction.
A computer program that translates high-level language statements to machine language.
The complement of a subset of a given set is the collection of all elements of the set that are not elements of the subset.
Complementarity Principle
The principle that a given system cannot exhibit both wave-like behavior and particle-like behavior at the same time.
Complementary Angles
Two angles whose sum is 90°.
Complementary Colours
For lights, two colours that combine to form white.
Complementary DNA
A DNA, usually made by reverse transcriptase, which is complementary to given mRNA and used in cloning.
Complementary Probability
Considering probabilites in decimal form, the sum of two probabilites equal to one.
Complementary Rules
Rules in Boolean Algebra derived from the combination of a single variable with the inverse of itself.
Complementary Slackness
Condition that two non-negative vectors are orthogonal.
Complementary Transistor
A PNP and NPN pair used in a push-pull circuit.
Complete Combustion
A combustion reaction that converts all of the fuel′s carbon, hydrogen, sulphur, and nitrogen into carbon dioxide, water, sulphur dioxide, and N2 respectively.
Complete Ionic Equation
A balanced equation that describes a reaction occurring in solution, in which all strong electrolytes are written as dissociated ions.
An object is complete if nothing needs to be added to it.
Completion Resistor
A resistor, typically a precision resistor, that completes a bridge measurement system and across which a voltage drop is measured.
Complex Compound
Compound contains two or more simpler compounds that can be packed in a definite ratio into a crystal.
Complex Conjugate
A complex number whose imaginary part is the negative of that of a given complex number, their real parts being equal.
Complex Ion
An ion formed by combination of simpler ions or molecules.
Complex Modes
The points on a structure have varying phase relationships between them at a natural frequency. This is unlike a real mode where the phase between points is either 0° or 180°.
Complex Modulus
Measure of dynamic mechanical properties of a material, taking into account energy dissipated as heat during deformation and recovery.
Complex Numbers
A complex number consists of a real and imaginary part.
Complex Numbers, Exponential Form
Exponential expression of complex numbers.
Complex Numbers, Logarithms of
A complex number expressed in logarithmic form.
Complex Numbers, Polar Form
Complex numbers written in polar form.
Complex Tone
Sound wave containing simple harmonic components of different frequencies.
Complexing Agent
A ligand that binds to a metal ion to form a complex.
Measure of computer time or space to solve a problem by an algorithm as a function of the problem′s dimensions.
Complexometric Titration
A titration based on a reaction between a ligand and a metal ion to form a complex.
The displacement caused by a unit force applied to a spring or structural component. It is the reciprocal of stiffness (Units m/N).
Compliance Voltage
The output dc voltage of a constant current supply.
Complimentary Metal Oxide Semiconductor
Family of logic devices that uses p-type and n-type channel devices on the same IC. It has the advantage of offering medium speed and very low power requirements.
An element or chemical compound that helps make up a material system.
Component Video
A video system for colour television that stores separate channels of red, green and blue.
A material brought about by combining materials differing in composition or form on a macroscale for the purpose of obtaining specific characteristics and properties.
Composite Acoustic Barriers
Acoustic barriers are generally made from panels of different acoustic performance.
Composite Materials
Structural materials of metals, ceramics, or plastics with built-in strengthening which may be in the form of filaments, foils, powders, or flakes of a different compatible material.
Composite Number
A natural number that is not prime.
Composite Rating of Preference
Combines low frequency sound and spectral balance i.e. modifiers for boom and high frequency.
Composite Video
A video signal combining luminance, chrominance, and synchronization data on a single coax cable using RCA connectors and colour-coded yellow.
Composite Volcano
A steep volcanic cone built by both lava flows and airborne rocks and ash.
Plant remains which are allowed to rot.
A pure substance which contains two or more different elements chemically bonded together in stoichiometric proportions.
Compound Gauge
Instrument for measuring pressures both above and below atmospheric pressure.
Compound Mitre Saw
A powered saw used to accurately cut straight, cross or compound mitres.
Compound Wound Motors and Generators
Machines that have a series field in addition to a shunt field.
Compounded Oil
A petroleum oil to which has been added other chemical substances.
Pressed into less space.
Compressed Air
Air at any pressure greater than atmospheric pressure.
Compressed Air Dryer
A devise that removes moisture from compressed air.
Compressed Hydrogen Gas
Hydrogen gas compressed to a high pressure and stored at ambient temperature.
Compressed Natural Gas
Natural gas compressed to a volume and density that is practical as a portable fuel supply.
The change in volume of a unit volume of a fluid when subjected to a unit change of pressure.
Compressibility and Recovery Test
Method for measuring behaviour of gasket materials under short time compressive loading at room temperature.
Compressible Fluids
Compressible flow requires the integration of the equations of conservation of mass and momentum with that of energy conservation.
A pressing force that squeezes a material together.
Compression Deflection Test
Nondestructive method for determining relationship between compressive load and deflection under load for vulcanized rubber.
Compression Fatigue
Ability of a material to sustain repeated fluctuating compressive loads.
Compression Ignition
Ignition of a fuel charge by the heat of the air in a cylinder, generated by compression of the air, as in the diesel engine.
Compression Moulding
Moulding technique using heat and pressure.
Compression Pressure
The pressure of the air charge at the end of the compression stroke.
Compression Ratio
In an engine, the ratio of the cylinder volume at BDC (Bottom Dead Centre) to cylinder volume at TDC (Top Dead Centre).
Compression Relief
A device to reduce the compression in a cylinder and thus to make cranking easier.
Compression Rings
Piston rings placed in the upper part of a piston to seal against loss of compression pressure and against gas blowing.
Compression Set
The extent to which a material is permanently deformed by a prolonged compressive load.
Compression Shackle
A short arm connecting the rear of the leaf spring to the frame which limits travel by compression.
Compression Stroke
The stroke of the piston during which the air charge in the cylinder is compressed by the piston movement.
Compression Test
Method for determining behaviour of materials under crushing loads.
Compressional Wave
Wave in an elastic medium which causes an element of the medium to change its volume without undergoing rotation.
Compressive Deformation
Extent to which a material deforms under a crushing load.
Compressive Strength
For metals, the compressive strength is the same as the tensile yield strength.
Compressive Stress
Stress on the cross-sectional area of a body normal to the compression force acting on the body
Compressive Yield Strength
Stress which causes a material to exhibit a specified deformation.
A mechanical device that increases the pressure of a gas by reducing its volume.
Compressor Wheel
The wheel on a turbocharge which pulls air and forces into the engine.
Compton Effect
An effect that demonstrates that photons have momentum.
Compton Electron
An orbital electron of an atom which has been ejected from its orbit as a result or an impact by a high-energy quantum of radiation.
Compton Wavelength
The Compton Wavelength is the wavelength associated with the mass of any particle.
Compund Event
Two or more events that happen simultaneously.
Compund Volcano
A volcano that consists of a complex of two or more vents.
Computational Chemistry
A branch of chemistry concerned with the prediction or simulation of chemical properties, structures, or processes using numerical techniques.
Computational Fluid Dynamics
A tool for predicting the aerodynamics and fluid dynamics of air around flight vehicles by solving a set of mathematical equations with a computer.
To solve problems that use numbers.
A data processor that can perform substantial computation, including numerous arithmetic or logic operations, without intervention by a human operator during the run.
Computer Aided Design
Usually applied to that part of CAE which has to do with the drawing or physical layout steps of engineering design.
Computer Aided Engineering
A technique for using computers to help with all phases of engineering design work.
Computer Aided Engineering Books
Lists all Computer Aided Engineering Books in the Encyclopaedia
Computer Aided Engineering Weblinks
Lists all Computer Aided Engineering Weblinks in the Encyclopaedia
Computer Assisted Drug Design
Using computational chemistry to discover, enhance, or study drugs and related biologically active molecules.
Computer Hardware
The physical parts of a computer.
Computer Network
Lists all Computer Network topics in the Encyclopaedia
Computer Network Books
Lists all Computer Network Books in the Encyclopaedia
Computer Network Weblinks
Lists all Computer Network Weblinks in the Encyclopaedia
Computer Noise
Noise and vibration generated by the cooling fans, disc drives and power supplies.
Computer Software
The programs that run on a computer.
Computer Virus
A program that has been deliberately created to cause computer problems.
Lists all the Comuting topics
Computing Conversions
Lists all Computing Conversions in the Encyclopaedia
Computing Efficiency
The percentage of the successful computation time during a defined period to the total time in that period.
Computing Weblinks
Lists all Computing Weblinks in the Encyclopaedia
Chemical formula for Cobalt II Nitrate.
To link together or place end to end.
Curved from the inside.
Concave Lens
Lens thinner in centre than edges; a diverging lens.
Concave Up
A curve is "concave up" when it is a concave shape, meaning curved like the inside of a bowl, with the two ends of the curve pointing up.
Concealed Hinge
Hinge so constructed that no parts are exposed when the door is closed.
To increase the amount of substance present in a unit amount of mixture.
Having a relatively large amount of substance present in a unit amount of mixture.
Concentrated Force
A force considered to act along a single line in space.
Concentrated Solar Power
The sun′s energy is captured with mirrors and concentrated to heat steam that then drives a turbine to produce electricity.
The amount of substance in a specified space.
Concentration Cell
A voltaic cell in which both compartments contain the same components, but at different concentrations.
Having a common centre.
Concentric Circles
Circles that have the same center and varying radii.
Concert Pitch
Established by the International Organisation for Standardisation in 1955, the agreed reference frequency of 440 Hz. for the note called middle A.
A pair of cases for two ordered data variables in which values for the first case are either both higher or both lower than the values of the variables for the second case.
Building material made from cement, sand, stone and water.

Concrete Aggregate
A mixture of sand, rock, crushed stone, expanded materials, or particles that typically compose 75% of concrete by volume.
Concrete Bullfloat
A large wooden or metal float on a long handle used in leveling and smoothing wet concrete.
Pertaining to the occurrence of two or more events or activities within the same specified interval of time.
Condensable Particulate Matter
Particulate matter, contained almost entirely within the PM2.5 classification, that forms from condensing gases or vapours.
The process by which vapour molecules reform a liquid.
Condensation Coefficient
The ratio of condensation rate to impingement rate.
Condensation Nucleus
A particle, either liquid or solid, upon which condensation of vapour begins.
Condensation Polymerization
The formation of polymers by an intermolecular reaction involving at least two monomer species.
Condensation Rate
The number per square metre per second at which molecules condense on a surface.
Condensation Shock Wave
A sheet of discontinuity associated with a sudden condensation and fog formation in a field of flow.
Condensation Trail
A cloud like streamer or trail often seen behind aircraft flying in clear, cold, humid air.
An old fashioned name for a capacitor.
Condenser Microphone
A type of microphone in which the diaphragm is one plate of a capacitor containing an electrical charge.
Condition Monitoring
The measurement, recording and analysis of machinery parameters (such as acceleration) to determine machinery health. Today′s condition is compared with earlier condition, as when a machine was new.
Conditional Probability
The probability of an event occurring given that another event also occurs.
The electrical conductance of a conductor is the reciprocal of the resistance of the conductor.
Conducting Polymer
A polymeric material having electronic conductivity.
This is the process by which heat flows from the hotter region of a substance to the colder region without there being any net flow of the material itself.
Conduction Band
Lowest empty or partially filled band in a semiconductor.
Having the property or capability of conducting.
Conductive Hearing Loss
Hearing loss due to the impairment of sound transmission before it reaches the inner ear.
The ease with which a substance transmits electricity.
An electroanalytical technique based upon the measurement of the conductivity an electrolyte solution.
A material that allows the passage of electric charge or the easy transfer of thermal energy.
A tubular raceway, usually metal or plastic, for holding wires or cables.
A three-dimensional solid that rises to a single point at the top. A type of light-sensitive cell in the retina.
Cone Clutch
The friction surfaces are on inner and outer cone surfaces.
Cone Pulley
A one-piece stepped pulley having two or more diameters.
Confidence Interval
A range of values which is believed to include, with a preassigned degree of confidence, the true characteristic of the lot or universe a given percentage of the time.
Confidence Level
The degree of desired trust or assurance in a given result.
Confidence Limits
The upper and lower extremes of the confidence interval.
The containment of plasma particles and energy within a container for some extended period of time.
Confocal Imaging
Technique that uses a source point and a confocal point to image an object.
Molecular arrangements that differ only by rotations around single bonds.
Elements belonging to the same group on the periodic table.
Equilateral, equal, exactly the same size and shape.
Congruent Angles
Two angles that are exactly the same.
Congruent Figures
Two geometric figures that are identical in size and shape.
Congruent Transformation
A transformation of one phase to another that does not involve any change in composition.
Conic Section
The cross section of a right circular cone cut by a plane.
Conical Pendulum
The motion of the wire from which the bob hangs describes the surface of a cone.
A statement that may seem to be true, but has yet to be proven.
Conjugate Acid
A substance which can lose a H+ ion to form a base.
Conjugate Base
A substance which can gain a H+ ion to form an acid.
Conjugate Tooth Pairs
Two gear teeth are conjugate if theyproduce uniform motion as they roll together.
Conjugated Protein
A protein containing one or more prosthetic groups.
Conjugated Redox Pair
An electron donor and its corresponding electron acceptor form.
The operation of replacing i by -i in a complex number.
Connected Set
A set that cannot be split into a union of two sets each of which is both open and closed.
Connecting Rod
The part in an internal combustion engine that connects the piston to the crankshaft.
Connecting Rod End
The end of the connecting rod that carries the bearing and connects to the crank and other end that connects to the piston.
A connection restrains degrees of freedom of one member with respect to another.
Abbreviation of connecting rod, the part in an internal combustion engine that connects the piston to the crankshaft.
Consecutive Sides
Sides of a polygon that share an endpoint.
Consecutive Vertices
Endpoints of a single side of a polygon.
Conservation Laws
A law which states that, in a closed system, the total quantity of something will not increase or decrease, but remain exactly the same; that is, its rate of change is zero.
Conservation of Angular Momentum
The total angular momentum of a system is constant unless an external torque acts on it.
Conservation of Charge
In an isolated system the total charge is conserved.
Conservation of Energy
The total energy of an isolated system does not change.
Conservation of Mass
The total mass in a closed system does not change even when physical and chemical changes occur.
Conservation of Momentum
If the net external force on a system is zero, the total linear momentum of the system does not change.
A greenhouse attached to a house.
This term is used in physics to mean that a number associated with a physical property does not change; it is invariant.
Consistent Linear System
A system of linear equations is consistent if it has at least one solution.
An array of controls and indicators for controlling a complex system or sequence of events.
Two or more sounds that, when heard together, sound pleasant.
Constancy Principle
One of the postulates of Einstein′s special theory of relativity, which puts forth that the speed of light in vacuum is measured as the same speed to all observers, regardless of their relative motion.
A quantity that does not change. This quantity may be a number or a variable.
Constant Air Volume
A system designed to provide a constant air flow.
Constant Current Battery Charger
A battery charger with output current that stays relatively constant as the battery state of charge increases.
Constant Functions
Functions that stay the same no matter what the variable does are called constant functions.
Constant Level Balloon
A balloon designed to float at a constant-pressure level.
Constant Linear Velocity
A disc rotating at varying numbers of revolutions per second to maintain a constant relative velocity between pickup and track across the disc radius.
Constant Percentage Bandwidth Filter
A band-pass filter whose bandwidth is a constant percentage of centre frequency. 1/3 octave filters are constant percentage bandwidth.
Constant Pressure Balloon
A balloon designed to float at a constant-pressure level. Also called a Constant Level Balloon.
Constant Pressure Combustion
Combustion of fuel in a cylinder at so slow a rate that there is no rise in cylinder pressure.
Constant Velocity Joint
A special type of shaft coupling that allows the smooth transfer of power from an input shaft to an output shaft at all angles.
Constant Volume Combustion
Combustion in a cylinder so fast that there is no change in volume.
An alloy of 40% nickel and 60% copper, with a high volume resistivity and almost negligible temperature coefficient. Used with copper in T-type thermocouples.

Constant-Speed Propeller
One which governs an engine at its optimum speed, the blade pitch being increased or decreased automatically to achieve this result.
A named grouping of fixed stars.
Constrained-Layer Damper
A layer of damping material between the structure′s surface and an additional elastic layer.
Construction Manager
A person who coordinates the entire construction process, from initial planning and foundation work through the structure′s completion.
Constructive Interference
When the peaks and troughs of two interfering waves match, the amplitudes add to give the resultant wave a higher amplitude.
Consulting Services
Lists all Consulting Services topics in the Encyclopaedia
Consulting Services Weblinks
Lists all Consulting Services Weblinks in the Encyclopaedia
The contact details for Dirac Delta Consultants, the authors of the Science and Engineering Encyclopaedia.
Contact Adsorption
Adsorption with the adsorbed molecule or ion being in direct contact with the solid surface.
Contact EMF
Electromotive force which arises at the contact of dissimilar metals at the same temperature, or the same metal at different temperatures.
Contact Moulding
A technique in which reinforcement and resin are placed in a mould, with cure taking place at room temperature with a catalyst/promoter system, or in a heated oven.
Contact Patch
Area of a tyre that actually touches the road.
Contact Potential
The voltage generated by the contact of two dissimilar metals or materials.
Contact Ratio
The contact ratio is the average numberof pairs of teeth in contact between two gears.
A contactor is a device for opening and closing an electric power circuit.
Any foreign or unwanted substance that can have a negative effect on system operation, life or reliability.
Continental Rise
The portion of the continental margin that lies between the abyssal plain and the continental slope.
Continental Shelf
The portion of the continental margin that extends as a gently sloping surface from the shoreline seaward to a marked change in slope at the top of the continental slope.
Continental Slope
That part of the continental margin that lies between the continental shelf and the continental rise.
An uninterrupted, complete path for current flow.
Continuity Equation
An equation which states that a fluid flowing through a pipe flows at a rate which is inversely proportional to the cross-sectional area of the pipe.
Continuous Casting
A casting technique in which an ingot, billet, tube, or other shape is continuously solidified while it is being poured, so that its length is not determined by mould dimensions.
Continuous Data
The values belonging to it may take on any value within a finite or infinite interval.
Continuous Filament
An individual, small-diameter reinforcement that is flexible and indefinite in length.
Continuous Filament Yarn
Yarn that is formed by twisting two or more continuous filaments into a single continuous strand.
Continuous Graph
In a graph, a continuous line with no breaks in it forms a continuous graph.
Continuous Span Beam Bridge
Simple bridge made by linking one beam bridge to another; some of the longest bridges in the world are continuous span beam bridges.
Continuous Spectrum
A plot of the relative absorbance or intensity of emitted light vs. wavelength or frequency that shows a smooth variation, rather than a series of sharp peaks or bands.
Continuous System
A continuous system is one that is considered to have an infinite number of possible independent displacements.
Continuously Variable Transmission
A drive system where a belt running on pairs of cones allows the ratio between the input and output shafts to be varied continuously between the maximum and minimum ratios.
Any set that may be brought into 1-1 correspondence with the set of real numbers. Examples: a finite line segment, a square, a circle, a disk.
The outline of an object.
Something that prevents pregnancy.
A reduction in size.
Acronym for CONdensation TRAIL. A cloud-like streamer or trail often seen behind aircraft flying in clear, cold, humid air.
Control Arms
A part of the suspension system designed to control wheel movement precisely.
Control Chart
A chart used to determine whether the distribution of data values generated by a process is stable over time.
Control Grid
The electrode of a vacuum tube, other than a diode, upon which a signal voltage is impressed to regulate the plate current.
Control Grid Modulator
Uses a variation of grid bias to vary the instantaneous plate voltage and current.
Control Group
The subjects in a controlled experiment who do not receive the treatment.
Control Loop
Feedback circuit used to control an output signal.
Control Relay
An auxiliary relay whose function is to initiate or permit the next desired operation in a control sequence.
Control Rod
A neutron-absorbing material.
Control System
A group of components systematically organized to perform a specific control purpose.
Control Variable
The inputs and outputs which a control system manipulates and measures to keep proper control.
Control Voltage
The voltage of the power supply used to energize a device in the switchgear.
Controlled Atmosphere Brazing
This process uses a non-corrosive powdered flux and an inert gas atmosphere.
Controlled Experiment
An experiment that uses the method of comparison to evaluate the effect of a treatment by comparing treated subjects with a control group, who do not receive the treatment.
A device that controls the operation of part or all of a system.
The heat is transfered from the solid or liquid by the surrounding gas.
Convector Heater
A heat exchange device that uses the heat in steam, hot water, or an electric resistance element to warm the air in a room; often called inaccurately, a radiator.
Convergent Beam Electron Diffraction
An electron probe is tightly focused on a specimen and the resulting pattern of diffracted electrons is observed.
Converging Lens
Lens that causes light rays to converge; usually a convex lens.
A physical transformation from one material or state to another.
Conversion Factor
A conversion factor is a fraction that relates one unit to another.
Lists all the Conversion calculations in the Encyclopaedia
The curved surface of a cylinder, as a sphere when viewed from without.
Convex Lens
Lens that is thicker in center than at edges.
Convolution meaning ..intertwined, coiled…
Chemical formula for Cobalt II Oxide.
Carboxylic acid group.
A piece of information sent by a Web server to a Web browser. The browser software is then expected to save the data and send it back to the server whenever the browser makes additional requests from the server.
Cookie Cutter Tuner
A mechanical magnetron tuning device that changes the frequency by changing the capacitance of the anode cavities.
A fluid used to remove heat.
Coolidge, William D
American physicist, who made major contributions to X-ray machines.
Cooling Efficiency
The overall efficiency of a cooling system, this may include fans, heat exchangers, pumps etc.
Cooling Fan
The size, specification and location of a cooling fan will depend upon the amount of heat that has to be dissipated from the object that has to be cooled.
Cooling System
System that extracts heat from a machine and ejects it to the surrounding world.
Cooperative Fuel Research Engine
A standardised single cylinder, overhead valve, variable compression ratio engine used for measuring octane or cetane quality.
Coordinate Plane
A plane with a point selected as an origin, some length selected as a unit of distance, and two perpendicular lines that intersect at the origin, with positive and negative direction selected on each line.
Coordinated Universal Time
By international agreement, the local time at the prime meridian, which passes through Greenwich, England.
Numbers that specify the position of a point or the position or orientation of a geometric object.
Coordination Number
The number of atomic or ionic nearest neighbours.
Abbreviation of Coefficient of Performance.
The top half of a horizontally parted mould.
Copernican Principle
The idea, suggested by Copernicus, that the Sun, not the Earth, is at the centre of the Universe.
Copernican System
A theory of planetary motions, proposed by Copernicus, according to which all planets move in circular orbits around the Sun.


Scientists from the Centre for Heavy Ion Research in Germany, led by Professor Sigurd Hofmann, discovered copernicium in fusion experiments in 1996.

Copernicus, Nicolaus
Polish astronomer who advanced the theory that the Earth and other planets revolve around the Sun.
Coping Saw
A small saw for cutting curves.
A set of points or lines that are all on a common plane.
A polymer that consists of two or more dissimilar mer units in combination along its molecular chains.
Noted for being ductile and having good electrical and thermal conductivity. It forms the basis of a number of alloys.
Copper Faced Hammer
A hammer with a round head made of copper or brass.
Copper I Bromide


Yellowish green or white crystalline solid.

Copper I Chloride


White crystalline solid. Turns green in moist air.

Copper I Iodide


White crystalline solid.

Copper I Oxide


A red powder.

Copper I Sulphide


Yellow, red, or brown crystalline solid.

Copper II Bromide


Black crystalline solid. Reacts violently with potassium.

Copper II Carbonate


Green or blue powder forming most of the patina one sees on weathered brass, bronze, and copper. Used as a pigment.

Copper II Hydroxide


Used as a fungicide.

Copper II Oxide


A black-brown crystalline solid.

Copper II Sulphide


Blue-black or black crystalline solid.

Copper Indium Diselenide


A polycrystalline thin-film photovoltaic material.

Copper Loss
The power lost because of the resistance of the conductors.
Copper Plating
The process in which a layer of copper is deposited on the item to be plated by using an electric current.
Copper Sulphate


A water soluble salt used in copper plating.

The mineral form of Iron II Sulphate.
Integers m and n are coprime if the greatest common divisor of m and n is 1.
A projecting wall member used as a support for some element of the superstructure.
Corbelled Arch
An arch constructed by successive layers of brick or stone projecting further towards each other from either side of the arch, until the gap is spanned.
An imperial unit of volume used mainly in the timber industry.
Cordless Screwdriver
A battery powered handheld screwdriver.
Cordwood Module
A method of increasing the number of discrete components in a given space.
Central region.
Core Electron
Electrons occupying completely filled shells under the valence shell.
Corinthian Order
The last of the three Greek orders, similar to the Ionic, but with the capital decorated with carvings of the acanthus leaf.
Coriolis Force
A fictitious force that occurs in rotating reference frames.
Outer waterproof layer covering most trees and shrubs. The cork material used in flooring and for it′s properties is from the tree Quercus Suber.

Corner Frequency
The frequency at which linear extrapolations of two contiguous sections of a device's or component′s transfer function drop by 3 decibels.
Corner Reflector Antenna
A half-wave antenna with a reflector consisting of two flat metal surfaces meeting at an angle behind the radiator.
A cornice is an ornamental molding, or composition of two or more moldings, located at the exterior wall-roof junction of a building, beneath the eaves, or beneath the sloping ends of a gable roof.
Corollary to a Theorem
A corollary is a proposition that follows with little or no proof from one other theorem or definition.
The outermost layer of the Sun′s atmosphere.
Corona Extinction Voltage
The highest voltage at which continuous corona of specified pulse amplitude no longer occurs as the applied voltage is gradually decreased from above the corona inception value.
Corona Inception Voltage
The lowest voltage at which continuous corona of specified pulse amplitude occurs as the applied voltage is gradually increased.
Coronal Mass Ejection
A huge cloud of hot plasma, occasionally expelled from the Sun.
Corporate Average Fuel Economy
A U.S. regulation requiring auto companies to meet certain sales weighted average fuel economy levels for passenger cars and light trucks and report these numbers annually.
Corpuscular Theory
The theory that light is transmitted as a stream of particles.
Correlated Double Sampling
A circuit commonly used to process the output signal from a CCD image sensor in order to reduce low-frequency noise components.
Generally speaking, a similarity between data; the extent to which data are related.
Correlation Coefficient
A numerical value, between +1 and -1, that identifies the strength of the linear relationship between variables.
Correspondence Principle
The principle that when a new, more general theory is put forth, it must reduce to the more specialized theory under normal circumstances.
Corresponding Angles
Two angles in the same relative position on two lines when those lines are cut by a transversal.
Deteriorative loss of a metal as a result of dissolution environmental reactions.
Corrosion Current Density
The current flowing in a corrosion "local" cell.
Corrosion Inhibitor
A lubricant additive for protecting surfaces against chemical attack from contaminants in the lubricant.
Corrosion Potential
The electrode potential of a corroding metal.
Corrosion Protection
Modification of a corrosion system so that corrosion damage is mitigated.
Corrosion Resistance
The ability of a material to resist deterioration by chemical or electrochemical reaction with its environment.
Having the power to dissolve. Can burn and destroy living tissue.
Corrosive Sublimate
Another name for Mercury II Chloride.
Corrosive Wear
A material deterioration due to the co-joint action of corrosion and mechanical action.
Trigonometric function.
Trigonometric function.
Trigonometric function.
Cosmic Background Radiation
Believed to be the cosmologically redshifted radiation released by the Big Bang itself.
Cosmic Noise
Interference caused by cosmic radio waves.
Cosmic Ray
An extremely energetic (relativistic) charged particle.
Cosmological Constant
The constant introduced to the Einstein field equation, intended to admit static cosmological solutions.
Cosmological Redshift
An effect where light emitted from a distant source appears redshifted because of the expansion of spacetime itself.
The study of the history of the universe.
The universe regarded as an orderly, harmonious whole.
A proton accelerator.
Trigonometric function.
Trigonometric function.
Coterminal Angles
Two angles that have the same terminal side.
Of or using runners or slides as a guiding mechanism.
Defined as the quantity of charge which passes any section of a conductor in one second when a current of one ampere is flowing.
Coulomb, Charles Augustin de
Physicist, best known for the formulation of Coulomb′s law.
Coulomb Damping
Coulomb damping is the dissipation of energy that occurs when a particle in a vibrating system is resisted by a force whose magnitude is constant independent of displacement and velocity, and whose direction is opposite to the direction of the velocity of the particle.
Coulombic Efficiency
For a rechargeable battery the fraction of the electrical charge stored during charging that is recoverable during discharge.
Coulombic Force
A force between charged particles, such as ions.
Instrument used for the measurement of electrical charge.
An electroanalytical technique based upon the measurement of the amount of electrical charge passed through the working electrode of an electrochemical cell.
Coulostatic Technique
Technique for electrochemical analysis or for the determination of the kinetics and mechanism of electrode reactions based on the control of the amount of charge flowing through the system.
Coulter Counter
Instrument used to count the number of small particles in a given volume of a suspension by monitoring decreases in electrical conductivity through a small orifice caused by the particles passing through the orifice.
A circuit that counts input pulses.
Counter Electrode
An electrode in a three-electrode cell that is used only to make an electrical connection to the electrolyte so that a current can be applied to the working electrode.
Counter EMF
Another name for Back Electromotive Force.
Counter Weight
A weight added to a body so as to reduce a calculated unbalance at a desired place.
The mobile ion in ion exchange.
To counter bore a hole such that the head of a screw may sit flush with the surface.
Two equal forces acting on a body in opposite directions and located at a specific distance apart produce a turning effect on the body.
Coupled Modes
Coupled modes are modes of vibration that are not independent but which influence one another because of energy transfer from one mode to the other.
Coupled Reactions
Two chemical reactions that have a common intermediate and thus a means of energy transfer from one to the other.
Mechanical fixture for joining two shafts.
Level layer of stones or bricks.
Cousteau, Jacques
French marine biologist, explorer, ecologist, filmmaker, photographer and researcher who studied the sea and all forms of life in water.
Covalent Bond
Describes the mutual electrostatic attraction of two or more adjacent nuclei for a shared pair of electrons which occupy the same molecular energy level.
Covalent Compound
A compound in which the atoms that are bonded share electrons rather than transfer electrons from one to the other.
Covalent Radius
The radius of atoms obtained from covalent bond lengths.
A measure of the joint variability of a pair of numeric variables.
Cover Glass
A clear glass used in goggles, hand shields, and helmets to protect the filter glass from spattering material.
Cover Slip
Very thin square piece of glass or plastic placed over the specimen on a microscope slide.
The name of the fairing which, usually, encloses an engine on an aeroplane.