| A | B |
|---|
| Alternative Energy | Any source of energy other than fossil fuels that is used for constructive purposes. |
| Conduction | The transfer of heat within an object or between objects by molecular activity, without any net external motion. |
| Convection | Process by which, in a fluid being heated, the warmer part of the mass will rise and the cooler portions will sink. |
| Electromagnetic Energy | Energy caused by the movement of light waves. |
| Electrolysis | The process separating the hydrogen-oxygen bond in water using an electrical current. |
| Energy | The ability to do work. |
| Entropy | The function of the state of a thermodynamic system whose change in any differential reversible process is equal to the heat absorbed by the system from its surroundings divided by the absolute temperature of the system. |
| First Law of Thermodynamics | The law that heat is a form of energy, and the total amount of energy of all kinds in an isolated system is constant; it is an application of the principle of conservation of energy. Also known as conservation of energy. |
| Fuel Cell Stack | Individual fuel cells that are combined in series. |
| Heat | Energy in transit due to a temperature difference between the source from which the energy is coming and a sink toward which the energy is going. |
| Kelvin | A unit of absolute temperature and symbolized as K. Formerly known as degree Kelvin. |
| Passive Solar Energy Collection | Systems that do not make use of any externally powered, moving parts, such as circulation pumps, to move heated water or air. |
| Product Development Life Cycle | Stages a product goes through from concept and use to eventual withdrawal from the market place. |
| Radiation | The process by which energy is transmitted through a medium, including empty space, as electromagnetic waves. This energy travels at the speed of light. This is also referred to as electromagnetic radiation. |
| Renewable Energy | A resource that can be replaced when needed. |
| R-value | The measure of resistance to heat flow. |
| Second Law of Thermodynamics | A general statement of the idea that there is a preferred direction for any process. |
| Temperature | A property of an object which determines the direction of heat flow when the object is placed in thermal contact with another object. |
| Thermal Equilibrium | Refers to the property of a thermodynamic system in which all parts of the system have attained a uniform temperature which is the same as that of the system’s surroundings. |
| Thermodynamic System | A part of the physical world as described by its thermodynamic properties such as temperature, volume, pressure, concentration, surface tension, and viscosity. |
| Thermodynamics | The study of the effects of work, heat, and energy on a system. |
| U-value | A measure of thermal transmittance through a material. |
| Zeroth Law of Thermodynamics | A law that if two systems are separately found to be in thermal equilibrium with a third system, the first two systems are in thermal equilibrium with each other; that is, all three systems are at the same temperature. Also known as thermodynamic equilibrium. |
