Fl

fl oz
Abbreviation of Fluid Ounce.
Flag
A variable which can take one of only two values.
Flagella
Long, rotating filaments enabling the bacteria to move in any direction.
Flagellum
A cell appendage used in propulsion.
Flame Annealing
Annealing in which the heat is applied directly by a flame.
Flame Engine
The working principle is similar to the hot air engine, except that this engine draws hot air into the cylinder.
Flame Hardening
Quench hardening in which the heat is applied directly by a flame.
Flame Softening
A method for softening steel by heating with a gas flame followed by slow cooling.
Flame Test
A test to identify some metals, e.g. with sodium the flame turns orange.
Flammability Limits
The flammability range of a gas is defined in terms of its lower flammability limit (LFL) and its upper flammability limit (UFL).
Flammable
Substance that can easily be set on fire and that will burn readily or quickly.
Flange
A relatively thin rim around a part.
Flange Nut
A nut with a built in washer to spread the load.
Flanking Line
A line of attached cumulus or towering cumulus clouds of descending height.
Flanking Sound Transmission
The transmission of sound from the sound source room to the receiving room by paths other than through the partition under test.
Flaps
Hinged surfaces normally located at the trailing edge of the wing designed to increase the wings lift and the slow-flight characteristics.
Flare Nut Spanner
A spanner which looks almost like an open ended spanner except the end curls around the nut further.
Flash Drive
A removable data storage device, usually thumb sized and plugged into the USB port.
Flash Memory
Non-volatile computer memory that can be electrically erased and reprogrammed.
Flash Point
The temperature when vapour pressure of a substance becomes high enough to allow the air/vapour layer over the substance to be ignited.
Flashing
A thin edge of material formed at the parting line of a casting or forging where it is forced out between the edges of the form or die.
Flat Belt Drive
A belt used to transmit power between two shafts.
Flat Chisel
Used to cut bars and rods to reduce surfaces and to cut sheet metal which is too thick or difficult to cut with tin snips.
Flat Howe Truss
Structural framework for supporting loads over long spans.
Flat Nose Pliers
Pliers with short pointed jaws.
Flat Pratt Truss
Structural framework for supporting loads over long spans.
Flat Sheet
Sheet with sheared, slit or sawed edges, which has been flattened or leveled.
Flat Wood Drill
A wood drill that has a centre point to locate the drill and flats that bore the hole.
Flathead Engine
Another name for a Sidevalve Engine.
Flatness
For rolled products, a distortion of the surface of sheet such as a bulge or a wave, usually transverse to the direction of rolling.
Flattop Window
An amplitude weighting of the time signal used with gated continuous signals to give them a slow onset and cut-off in order to reduce the generation of side lobes in their frequency spectrum.
Flavour
A characteristic that distinguishes different types of hadrons and leptons with different masses.
Fleming, Alexander
Bacteriologist who isolated lysozyme from tears and observed a mould that he named penicillin.
Fleming, Sir John Ambrose
British electrical engineer and inventor known for his work on electric lighting, wireless telegraphy, and the telephone.
Fleming, Sir Sandford
Scottish-born Canadian engineer and inventor, known for proposing worldwide standard time zones, Canada′s postage stamp, a huge body of surveying and map making, engineering much of the Intercolonial Railway and the Canadian Pacific Railway.
Fleming Valve
An earlier name for a diode, or a two-electrode vacuum tube used as a detector.
Flemings Left Hand Rule
A way of determining the direction of a force on a current carrying conductor in a magnetic field.
Flemings Right Hand Rule
A way of determining the direction of the induced emf of a conductor moving in a magnetic field.
Flemish Bond
A particular arrangement of bricks.
Fletcher-Munson Curves
Our sensitivity to sound depends on its frequency and volume. Human ears are most sensitive to sounds in the midrange. At lower volume levels humans are less sensitive to sounds away from the midrange, bass and treble sounds "seem" reduced in intensity at lower listening levels.
Flexible Coaxial Cable
A line made with an inner conductor that consists of flexible wire insulated from the outer conductor by a solid, continuous insulating material.
Flexible Fuel Vehicle
A vehicle that can be run on any blend of unleaded gasoline with up to 85 percent ethanol.
Flexural Strength
A property of a solid that indicates its ability to withstand bending.
Flexure Mode
Flexure modes are associated with thin slender beams.
Flicker
Impression of fluctuating luminance or colour.
Flicker Noise
A type of low frequency noise where the power spectral density is inversely proportional to the frequency.
Flight Controls
Moveable surfaces on the aircraft that control its path through the air.
Flint Glass
An optical glass with higher dispersion and higher refractive index than crown glass; a heavy, brilliant glass, softer than crown glass.

Flip Chip
A monolithic IC packaging technique that eliminates the need for bonding wires.
Flip Flop
An astable multivibrator.
Flitch
A section of timber cut lengthwise from the trunk of the tree
Float Valve
A valve which automatically opens or closes as the level of a liquid changes.
Float Voltage
The voltage at which the battery is floated, or just enough current is supplied to equal the self-discharge of the battery.
Floating Point Number
A number represented in the computer in mantissa and exponent form.
Floating Point Operations per Second
A measure of a computer′s performance, especially in fields of scientific calculations that make heavy use of floating point calculations.
Flock
An old British unit of quantity equal to 2 score or 40.
Flooded Cell
A design for lead-acid batteries where the electrolyte is an ordinary liquid solution of acid.
Floor
The walking surface of a room or vehicle.
Floor Clamp
Aids to fixing tongue and grooved flooring.
Floor Function
The floor function of x is the greatest integer in x, i.e. the largest integer less than or equal to x.
Floorboard Saw
A saw with teeth which run around the back edge for easier cutting of floorboards in situ.
FLOPS
Abbreviation of Floating Point Operations per Second.
Florentine Bronze
A modern term for an alloy usually formed as a mixture of aluminium or tin (<10%) and copper (>90%).

Flow Battery
A battery system in which the active materials of one or both electrode polarities are stored externally and pumped to the battery during operation.
Flow Control Valve
A device used to control the flow of fluid contained in a pipe line.
Flow Lines
Texture showing the direction of metal flow during hot or cold working.
Flow Noise
A term generally used to describe aerodynamic noise produced when a gas flows within a duct or when the gas exits the duct.
Flow Rate
Volume per unit of time.
Flow Stress
The shear stress required to cause plastic deformation of solid metals.
Flowers of Antimony
Alternative name for Antimony Trioxide.
Fluctuation Strength
This is similar in principle to roughness except it quantifies subjective perception of slower, up to 20Hz, amplitude modulation of a sound.
Flue
A large fire tube, either used as the main heating surface in a flued boiler, or used as enlarged firetubes in a locomotive-style boiler where these contain the superheater elements.
Fluid Dynamics
Lists all Fluid Dynamics topics in the Encyclopaedia
Fluid Dynamics Books
Lists all Fluid Dynamics Books in the Encyclopaedia
Fluid Dynamics Calculations
Lists all Fluid Dynamics Calculations in the Encyclopaedia
Fluid Dynamics Conversions
Lists all Fluid Dynamics Conversions in the Encyclopaedia
Fluid Dynamics Weblinks
Lists all Fluid Dynamics Weblinks in the Encyclopaedia
Fluid Film Bearing
A bearing which supports the shaft on a thin film of oil.
Fluid Friction
Friction due to the viscosity of fluids.
Fluid Opacity
Related to the ability of a fluid to pass light.
Fluid Ounce
20 fluid ounces = 1 pint
Fluid Power
Energy transmitted and controlled through use of a pressurized fluid.
Fluid Velocity
The measured speed at which a fluid moves through the inside of a tube.
Fluids
Substances in which the binding forces are weaker than in solids.
Fluorescence
The property of a material whereby it emits visible light when it is illuminated by ultraviolet light.
Fluorescent Tube
A gas-discharge lamp that uses electricity to excite mercury vapour.
Fluorine
A pale greenish yellow gas that is the first in the halogen group.
Fluorotrichloromethane
Alternative name for Trichlorofluoromethane.
Flute
The groove in a cutting tool which provides a cutting edge and a space for the chips to escape and permits the cutting fluids to reach the cutting edges.
Flutter Echo
A repetitive echo set up by parallel reflecting surfaces.
Flux
The rate of flow of a physical quantitiy through a reference surface.
Flux Density
The number of magnetic lines of force passing through a given area.
Flux Dip Brazing
The component is immersed in a molten salt which acts as a flux as well as a heat source for melting the clad layer.
Fly Ash
Uncombusted particulate matter in the combustion gases resulting from the burning of coal and other material.
Fly Cutter
A single-point cutter mounted on a bar in a fly cutter holder or a fly cutter arbour used for special applications for which a milling cutter is not available.
Flying Buttress
A structure that adds support to a high wall or arch from a lower wall or arch.
Flywheel
The wheel on the end of the crankshaft that gives the crankshaft momentum to carry the pistons through the compression stroke.
Flywheel Battery
A battery in which the energy is stored in a flywheel, electrical energy is added or removed from the rotating flywheel using an electric motor.
Flywheel Effect
The continuous interchange of electric energy between the capacitor and inductor of a parallel resonant circuit wherein the energy level is diminished only by circuit resistance and radiated energy.