Usually waste products released to the atmosphere such as exhaust gases from combustion engines.

The process to remove pollutants from exhaust gases thereby reducing the impact on the environment.

A backup heat source that is activated if heat pump shuts off.

A small generator that will be used in the event that the main supply is interupted.

Emergency core cooling systems are designed to safely shut down a nuclear reactor during accident conditions.

Emergence occurs when an entity is observed to have properties its parts do not have on their own, properties or behaviors which emerge only when the parts interact in a wider whole.

Embodied energy is the sum of all the energy required to produce any goods or services, considered as if that energy was incorporated or 'embodied' in the product itself.

An embankment dam is a large artificial dam.

Electrowetting is the modification of the wetting properties of a surface (which is typically hydrophobic) with an applied electric field.

Electrostatics is a branch of physics that studies electric charges at rest.

An electrostatic generator, or electrostatic machine, is an electromechanical generator that produces static electricity, or electricity at high voltage and low continuous current.

An electronvolt is the amount of kinetic energy gained by a single electron accelerating from rest through an electric potential difference of one volt in vacuum.

Electronics which deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies.

The electronic–hydraulic analogy is the most widely used analogy for "electron fluid" in a metal conductor.

The electron is a subatomic particle whose electric charge is negative one elementary charge.

Nuclear fuel is a material that can be 'burned' by nuclear fission or fusion to derive nuclear energy.

The nuclear force is a force that acts between the protons and neutrons of atoms.

A nuclear flask is a shipping container that is used to transport active nuclear materials between nuclear power station and spent fuel reprocessing facilities.

Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission.

The fuel for nuclear fission reactor usually consists of a low-enriched oxide material (e.g.