This is a positive constant, k, that is a property of a substance and is used in the calculation of heat transfer rates for materials. It is the amount of heat that flows through a specified area and thickness of a material over a specified period of time ...

The ratio of chemical substances necessary for a reaction to occur completely.

A window located high in a wall near the eaves that allows daylight into a building interior, and may be used for ventilation and solar heat gain.

To send electricity through a electricity transmission and distribution network; a conductor or power line that is carrying current.

A registered trademark for a cholorflourocarbon (CFC) gas that is highly stable and that has been historically used as a refrigerant.

A door-like device located at the mouth of a fireplace chimney flue for controlling the direction and flow of the draft in the fireplace as well as the amount of oxygen that the fire receives.

A type of hydropower turbine that contains a runner that has water passages through it formed by curved vanes or blades. As the water passes through the runner and over the curved surfaces, it causes rotation of the runner. The rotational motion is transm ...

The total radiation incident on a specific surface area over a time interval.

Chemical reactions, typically associated with combustion processes; the balancing of chemical reactions by providing the exact proportions of reactant compounds to ensure a complete reaction; all the reactants are used up to produce a single set of produc ...

A type of furnace or reactor in which the emission of sulfur compounds is lowered by the addition of crushed limestone in the fluidized bed thus obviating the need for much of the expensive stack gas clean-up equipment. The particles are collected and rec ...

Period of time a system or appliance (or component of) is expected to function at its nominal or design capacity without major repair.

The difference in electrical pressure (voltage) between any two points in an electrical system or between any point in an electrical system and the earth.

In reference to a wind energy conversion device's blades, the difference between the rotational speed of the tip of the blade and the actual velocity of the wind.

The duration and periodicity of the operation of a device.

A device, or system of devices, that allows electrical current to flow through it and allows voltage to occur across positive and negative terminals.

Conventional turbine generators are used with the dry steam resources. The steam is used directly, eliminating the need for boilers and boiler fuel that characterizes other steam-power-generating technologies. This technology is limited because dry-steam ...

The process of forcing, either manually or automatically, a wind turbine's blades out of the direction of the wind in order to stop the blades from turning.

A federal government agency created in 1977, that is entrusted to contribute to the welfare of the United States by providing technical information, and a scientific and educational foundation for technology, policy and institutional leadership to achieve ...

The environmental, social, and economic impacts of producing a good or service that are not directly reflected in the market price of the good or service.

A device used to compress air for mechanical or electrical power production, and in air conditioners, heat pumps, and refrigerators to pressurize the refrigerant and enabling it to flow through the system.