Page 60 - Curriculum Visions Dynamic Book

DORMANT: A period of inactivity such as during winter, when plants stop growing.
DRAWING: The process in which a piece of metal is pulled over a former or through dies.
DRy-CLEANED: A method of cleaning fabrics with nonwater-based organic solvents such as carbon tetrachloride.
DuCTILE: Capable of being drawn out or hammered thin.
DyE: A coloured substance that will stick to another substance so that both appear to be coloured.
EARLy WOOD: The wood growth put on the spring of each year.
EARTHENWARE: Pottery that has not been fired to the point where some of the clay crystals begin to melt and fuse together and is thus slightly porous and coarser than stoneware or porcelain.
ELASTIC: The ability of an object to regain its original shape after it has been deformed.
ELASTIC CHANGE: To change shape elastically.
ELASTICITy: The property of a substance that causes it to return to its original shape after it has been deformed in some way.
ELASTIC LIMIT: The largest force that a material can stand before it changes shape permanently.
ELECTRODE: A conductor that forms one terminal of a cell.
ELECTROLySIS: An electrical-chemical process that uses an electric current to cause the breakup of a compound and the movement of metal ions in a solution. It is commonly used in industry for purifying (refining) metals or for plating metal objects with a fine, even metal coat.
ELECTROLyTE: An ionic solution that conducts electricity.
ELECTROMAGNET: A temporary magnet that is produced when a current of electricity passes through a coil of wire.
ELECTRON: A tiny, negatively charged particle that is part of an atom. The flow of electrons through a solid material such as a wire produces an electric current.
ELEMENT: A substance that cannot be decomposed into simpler substances by chemical means, for example, silver and copper.
EMuLSION: Tiny droplets of one substance dispersed in another.
EMuLSION PAINT: A paint made of an emulsion that is water soluble (also called latex paint).
ENAMEL: A substance made of finely powdered glass coloured with a metallic oxide and suspended in oil so that it can be applied with a brush. The enamel is then heated, the oil burns away, and the glass fuses. Also used colloquially to refer to certain kinds of resin-based paint that have extremely durable properties.
ENGINEERED WOOD PRODuCTS:
Wood products such as plywood sheeting made from a combination of wood sheets, chips or sawdust, and resin.
EVAPORATION: The change of state of a liquid to a gas. Evaporation happens below the boiling point.
ExOTHERMIC REACTION: A chemical reaction that gives out heat.
ExTRuSION: To push a substance through an opening so as to change its shape.
FABRIC: A material made by weaving threads into a network, often just referred to as cloth.
FELTED: Wool that has been hammered in the presence of heat and moisture to change its texture and mat the fibres.
FERRITE: A magnetic substance made of ferric oxide combined with manganese, nickel, or zinc oxide.
FIBRE: A long thread.
FILAMENT: (i) The coiled wire used inside
a light bulb. It consists of a high-resistance metal such as tungsten that also has a high melting point. (ii) A continuous thread produced during the manufacture of fibres.
FILLER: A material introduced in order to give bulk to a substance. Fillers are used in making paper and also in the manufacture of paints and some adhesives.
FILTRATE: The liquid that has passed through a filter.
FLOOD: When rivers spill over their banks and cover the surrounding land with water.
FLuID: Able to flow either as a liquid or a gas.
FLuORESCENT: A substance that gives out visible light when struck by invisible waves, such as ultraviolet rays.
FLux: A substance that lowers the melting temperature of another substance. Fluxes are use in glassmaking and in melting alloys. A flux is used, for example, with a solder.
FORMER: An object used to control the shape or size of a product being made, for example, glass.
FOAM: A material that is sufficiently gelatinous to be able to contain bubbles of gas. The gas bulks up the substances, making it behave as though it were semi- rigid.
FORGE: To hammer a piece of heated metal until it changes to the desired shape.
FRACTION: A group of similar components of a mixture. In the petroleum industry the light fractions of crude oil are those with the smallest molecules, while the medium and heavy fractions have larger molecules.
FRACTIONAL DISTILLATION: The separation of the components of a liquid mixture by heating them to their boiling points.
FREEzING POINT: The temperature at which a substance undergoes a phase change from a liquid to a solid. It is the same temperature as the melting point.
FRIT: Partly fused materials of which glass is made.
FROTH SEPARATION: A process in which air bubbles are blown through a suspension, causing a froth of bubbles to collect on the surface. The materials that are attracted to the bubbles can then be removed with the froth.
FuRNACE: An enclosed fire designed to produce a very high degree of heat for melting glass or metal or for reheating objects so they can be further processed.
FuSING: The process of melting particles of a material so they form a continuous sheet or solid object. Enamel is bonded
to the surface of glass this way. Powder- formed metal is also fused into a solid piece. Powder paints are fused to the surface by heating.
GALVANIzING: The application of a surface coating of zinc to iron or steel.
GAS: A form of matter in which the molecules take no definite shape and are free to move around to uniformly fill any vessel they are put in. A gas can easily be compressed into a much smaller volume.
GIANT MOLECuLES: Molecules that have been formed by polymerisation.
GLASS: A homogeneous, often transparent material with a random noncrystalline molecular structure. It is achieved by cooling a molten substance very rapidly so that it cannot crystallize.
GLASS CERAMIC: A ceramic that is not entirely crystalline.
GLASSy STATE: A solid in which the molecules are arranged randomly rather than being formed into crystals.
GLOBAL WARMING: The progressive increase in the average temperature of the Earth’s atmosphere, most probably in large part due to burning fossil fuels.
GLuE: An adhesive made from boiled animal bones.
GOB: A piece of near-molten glass used by glass-blowers and in machines to make hollow glass vessels.
GRAIN: (i) The distinctive pattern of fibres in wood. (ii) Small particles of a solid, including a single crystal.
GRAPHITE: A form of the element carbon with a sheetlike structure.
GRAVITy: The attractive force produced because of the mass of an object.
GREENHOuSE EFFECT: An increase in the global air temperature as a result of heat released from burning fossil fuels being absorbed by carbon dioxide in the atmosphere.
GREENHOuSE GAS: Any of various gases that contribute to the greenhouse effect, such as carbon dioxide.
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