Fiber Optic Wiki

Evolution of Ethernet

November 26, 2011

Ethernet evolved to include higher bandwidth, improved media access control methods, and different physical media. The coaxial cable was replaced with point-to-point links connected by Ethernet repeaters or switches to reduce installation costs, increase reliability, and improve management and troubleshooting. Many variants of Ethernet remain in common use.

Auto DR

November 25, 2011

Buildings account for more than 70 percent of electricity use globally. Auto DR enables utilities to call on commercial facilities to automatically decrease consumption during times of peak demand, reducing the load on the electrical network. Building operators work with an energy expert like Honeywell to develop custom strategies to decrease their energy use, utility bills and carbon dioxide emissions. DNOs, in turn, are able to alleviate grid congestion caused by older transmission and distribution equipment, which is already stressed and struggling to handle the necessary throughput. The prevailing alternative is to replace or reinforce the electrical network and associated equipment, which requires significant capital investment and construction in highly developed urban areas.

Electromagnetic radiation is a transverse wave

November 25, 2011

Electromagnetic radiation is a transverse wave meaning that the oscillations of the waves are perpendicular to the direction of energy transfer and travel. An important aspect of the nature of light is frequency.

Speed of propagation

November 25, 2011

Any electric charge that accelerates, or any changing magnetic field, produces electromagnetic radiation. Electromagnetic information about the charge travels at the speed of light. Accurate treatment thus incorporates a concept known as retarded time, which adds to the expressions for the electrodynamic electric field and magnetic field.

Hermal radiation and electromagnetic radiation as a form of heat

November 25, 2011

The basic structure of matter involves charged particles bound together in many different ways. When electromagnetic radiation is incident on matter, it causes the charged particles to oscillate and gain energy. The ultimate fate of this energy depends on the situation.

Arbitrary electromagnetic spectrum

November 25, 2011

In general, EM radiation (the designation 'radiation' excludes static electric and magnetic and near fields) is classified by wavelength into radio, microwave, infrared, the visible region we perceive as light, ultraviolet, X-rays, and gamma rays.

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