Definitions - u

U-value applies the factor of time to the heat-loss measurement. U-values measure heat that escapes per hour through a window. Windows typically have two U-values: one for the glass and one for the window, including the frame.

The biophysical environment is the symbiosis between the physical environment and the biological life forms within the environment, and includes all variables that comprise the Earth's biosphere.

Wikipedia Entry

A method of land disposal in which liquid wastes are injected into known geological formations, generally at great depths.

All oils requiring further refinery processing, except those requiring only mechanical blending. Includes naphtha and lighter oils, kerosene and light gas oils, heavy gas oils, and residuum.

A territory with one or more features present throughout and absent or unimportant elsewhere.

The ability to increase a product’s performance or features without replacing the product.

The upward flow of cold, nutrient-rich water toward the ocean surface as currents or seasonal winds draw warmer water away from a coast. Phytoplankton that feed in upwellings often support huge fish populations.

Energy obtained from sources that are essentially inexhaustible, unlike, for example, the fossil fuels, of which there is a finite supply. Renewable sources of energy include wood, waste, geothermal, wind, photovoltaic, and solar thermal energy.