Environmental Engineering Reference
In-Depth Information
Initial attack:
An aggressive action to put a fire out consistent with firefighter and
public safety and the valuables being protected.
Interferometric synthetic aperture radar (InSar):
A remote sensing technique
that uses radar satellite images to determine movement of the surface of
the Earth.
Interjurisdictional fish:
Populations of fish that are managed by two or more states
or national or tribal governments because of the scope of their geographic
distributions or migrations.
Internal collector storage:
A solar thermal collector in which incident solar radia-
tion is absorbed by the storage medium.
Interpretive facilities:
Structures that provide information about an event, place, or
thing by a variety of means, including printed, audiovisual, or multimedia
materials (e.g., kiosks that offer printed materials and audiovisuals, signs,
trail heads).
Introduced invasive species:
Non-native species that have been introduced into an
area and, because of their aggressive growth and lack of natural predators,
displace native species.
Invasive species:
An alien species whose introduction causes or is likely to cause
economic or environmental harm or harm to human health.
Invertebrate:
Any animal lacking a backbone or bony segment that encloses the
central nerve cord.
Ion exchange:
Reversible exchange of ions adsorbed on a mineral or synthetic poly-
mer surface with ions in solution in contact with the surface. A chemical
process used for recovery of uranium from solution by the interchange of
ions between a solution and a solid, commonly a resin.
Irradiance:
The direct, diffuse, and reflected solar radiation that strikes a surface.
Isobutane (C
4
H
10
):
A branch-chain saturated (paraffinic) hydrocarbon extracted
from both natural gas and refinery gas streams which is gaseous at standard
temperature and pressure. It is a colorless gas that boils at a temperature of
11°F.
Isobutylene (C
4
H
8
):
A branch-chain olefinic hydrocarbon recovered from refinery
or petrochemical processes which is gaseous at standard temperature and
pressure. Isobutylene is used in the production of gasoline and various pet-
rochemical products.
Isohexane (C
6
H
14
):
A saturated branch-chain hydrocarbon. It is a colorless liquid
that boils at a temperature of 156.2°F.
Isomerization:
A refining process that alters the fundamental arrangement of atoms
in the molecule without adding or removing anything from the original
material. Used to convert normal butane into isobutane (C
4
), an alkylation
process feedstock, and normal pentane and hexane into isopentane (C
5
) and
isohexane (C
6
), high-octane gasoline components.
Isotopes:
Forms of the same chemical element that differ only by the number of neu-
trons in their nucleus. Most elements have more than one naturally occur-
ring isotope. Many isotopes have been produced in reactors and scientific
laboratories.