Environmental Engineering Reference
In-Depth Information
Transportation sector:
An energy-consuming sector that consists of all vehicles
whose primary purpose is transporting people and/or goods from one phys-
ical location to another. Included are automobiles; trucks; buses; motorcy-
cles; trains, subways, and other rail vehicles; aircraft; and ships, barges, and
other waterborne vehicles. Vehicles whose primary purpose is not trans-
portation (e.g., construction cranes and bulldozers, farming vehicles, ware-
house tractors and forklifts) are classified in the sector of their primary use.
Tu rbid it y:
Refers to the extent to which light penetrates a body of water. Turbid
waters are those that do not generally support net growth of photosynthetic
organisms.
Turbine:
A machine for generating rotary mechanical power from the energy of
a stream of fluid (such as water, steam, or hot gas). Turbines convert the
kinetic energy of fluids to mechanical energy through the principles of
impulse and reaction, or a mixture of the two.
U
U-factor:
A measure the rate of heat loss or how well a product prevents heat from
escaping. It includes the thermal properties of the frame as well as the glaz-
ing. The insulating value is indicated by the R-value, which is the inverse
of the U-factor. U-factor ratings generally fall between 0.20 and 1.20. The
lower the U-factor, the greater a product's resistance to heat flow and the
better its insulating value.
Under reamer:
A drilling device that can enlarge a drill hole. The device is placed
about the drill bit and can be opened to drill and then closed to be brought
back up through a smaller diameter hole or casing.
Upwind turbine:
A turbine that faces into the wind; it requires a wind vane and yaw
drive in order to maintain proper orientation in relation to the wind.
Useful heat:
Heat stored above room temperature (in a solar heating system).
Useful thermal output:
The thermal energy made available for use in any industrial
or commercial process or used in any heating or cooling application (i.e.,
total thermal energy made available for processes and applications other
than electrical generation).
V
Vapor dominated:
A geothermal reservoir system in which subsurface pressures
are controlled by vapor rather than by liquid. Sometimes referred to as a
dry-steam reservoir
.
Variable-speed wind turbine:
Turbines in which the rotor speed increases and
decreases with changing wind speed, producing electricity with a variable
frequency.
Ver na l pool:
A type of seasonal wetland formed by isolated depressions in the land-
scape that hold water in the winter and spring and are usually dry by mid-
summer or fall.
