Environmental Engineering Reference
In-Depth Information
Reactor:
The body that provides the reaction to the displacer. It could be a body
fixed to the seabed, or the seabed itself. It could also be another structure or
mass that is not fixed but moves in such a way that reaction forces are cre-
ated (e.g., by moving by a different amount or at different times). A degree
of control over the forces acting on each body and/or acting between the
bodies (particularly stiffness and damping characteristics) is often required
to optimize the amount of energy captured. In some designs, the reactor is
actually inside the displacer, whereas in others it is an external body.
Reclamation:
Process of restoring surface environment to acceptable pre-existing
conditions. Includes surface contouring, equipment removal, well plugging,
revegetation, etc.
Recovery factor:
Fraction of total resources that can be extracted for productive uses.
Recycling:
The process of converting materials that are no longer useful as designed
or intended into a new product.
Reflectivity:
The ratio of the energy carried by a wave after reflection from a surface
to its energy before reflection.
Refuge lands:
Lands in which the National Forest Service holds full interest in fee
title, such as an easement.
Renewable energy:
Energy that is produced using resources that regenerate quickly
or are inexhaustible. Wind energy is considered inexhaustible, because
although it may blow intermittently it will never stop.
Renewable energy resources:
Energy resources that are naturally replenishing but
flow limited. They are virtually inexhaustible in duration but limited in
the amount of energy that is available per unit of time. Renewable energy
resources include biomass, hydropower, geothermal, solar, wind, ocean
thermal, wave action, and tidal action.
Renewable Portfolio Standard (RPS):
A mandate requiring that renewable energy
provide a certain percentage of total energy generation or consumption.
Reservoir:
A natural underground container of liquids, such as water or steam (or,
in the petroleum context, oil or gas).
Residues:
Bark and woody materials that are generated in primary wood-using mills
when roundwood products are converted to other products. Examples are
slabs, edgings, trimmings, sawdust, shavings, veneer cores and clippings,
and pulp screenings. Includes bark residues and wood residues (both coarse
and fine materials) but excludes logging residues.
Resistivity survey:
The measurement of the ability of a material to resist or inhibit
the flow of an electrical current, measured in ohm-meters. Resistivity is
measured by the voltage between two electrodes while an electrical current
is generated between two other electrodes. Resistivity surveys can be used
to delineate the boundaries of geothermal fields.
Resource base:
All of a given material in the Earth's crust, whether its existence is
known or unknown, and regardless of cost considerations.
Ribbon silicon:
Single-crystal silicon derived by means of fabricating processes
that produce sheets or ribbons of single-crystal silicon. These processes
include edge-defined film-fed growth, dendritic web growth, and ribbon-
to-ribbon growth.
