GLOSSARY
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Flexible-fuel vehicle (flex-fuel vehicle): A vehicle that can run
alternately on two or more sources of fuel; includes cars capable
of running on gasoline and gasoline/ethanol mixtures, as well
as cars that can run on both gasoline and natural gas.
Fluid coking: A continuous fluidised solids process that cracks feed
thermally over heated coke particles in a reactor vessel to gas,
liquid products, and coke.
Fluidized-bed boiler: A large, refractory-lined vessel with an air
distribution member or plate in the bottom, a hot gas outlet in or near the top, and some provisions for introducing
fuel; the fluidized bed is formed by blowing air up through
a layer of inert particles (such as sand or limestone) at a rate
that causes the particles to go into suspension and continuous motion.
Fly ash: Small ash particles carried in suspension in combustion
products.
Forest land: Land at least 10% stocked by forest trees of any size,
including land that formerly had such tree cover and that will be
naturally or artificially regenerated; includes transition zones,
such as areas between heavily forested and non-forested lands
that are at least 10% stocked with forest trees and forest areas
adjacent to urban and built-up lands; also included are pinyonjuniper and chaparral areas; minimum area for classification of
forest land is 1 acre.
Forest residues: Material not harvested or removed from logging
sites in commercial hardwood and softwood stands as well as
material resulting from forest management operations such
as pre-commercial thinnings and removal of dead and dying
trees.
Forest health: A condition of ecosystem sustainability and attainment of management objectives for a given forest area; usually considered to include green trees, snags, resilient stands
growing at a moderate rate, and endemic levels of insects and
disease.
Formation: An interval of rock with distinguishable geologic
characteristics.
Fossil fuel: Solid, liquid, or gaseous fuels formed in the ground
after millions of years by chemical and physical changes in
plant and animal residues under high temperature and pressure. Oil, natural gas, and coal are fossil fuels.
293
Flexible-fuel vehicle (flex-fuel vehicle): A vehicle that can run
alternately on two or more sources of fuel; includes cars capable
of running on gasoline and gasoline/ethanol mixtures, as well
as cars that can run on both gasoline and natural gas.
Fluid coking: A continuous fluidised solids process that cracks feed
thermally over heated coke particles in a reactor vessel to gas,
liquid products, and coke.
Fluidized-bed boiler: A large, refractory-lined vessel with an air
distribution member or plate in the bottom, a hot gas outlet in or near the top, and some provisions for introducing
fuel; the fluidized bed is formed by blowing air up through
a layer of inert particles (such as sand or limestone) at a rate
that causes the particles to go into suspension and continuous motion.
Fly ash: Small ash particles carried in suspension in combustion
products.
Forest land: Land at least 10% stocked by forest trees of any size,
including land that formerly had such tree cover and that will be
naturally or artificially regenerated; includes transition zones,
such as areas between heavily forested and non-forested lands
that are at least 10% stocked with forest trees and forest areas
adjacent to urban and built-up lands; also included are pinyonjuniper and chaparral areas; minimum area for classification of
forest land is 1 acre.
Forest residues: Material not harvested or removed from logging
sites in commercial hardwood and softwood stands as well as
material resulting from forest management operations such
as pre-commercial thinnings and removal of dead and dying
trees.
Forest health: A condition of ecosystem sustainability and attainment of management objectives for a given forest area; usually considered to include green trees, snags, resilient stands
growing at a moderate rate, and endemic levels of insects and
disease.
Formation: An interval of rock with distinguishable geologic
characteristics.
Fossil fuel: Solid, liquid, or gaseous fuels formed in the ground
after millions of years by chemical and physical changes in
plant and animal residues under high temperature and pressure. Oil, natural gas, and coal are fossil fuels.