low-frequency loss
71Control of the National Grid — The National Grid is the high voltage electric power transmission network in Great Britain, connecting power stations and major substations, and has a synchronized organization such that electricity generated anywhere in Great Britain can be used …
72Ionosphere — The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner …
73Hearing impairment — See also: Deaf culture for the social movement.. Deaf and/or hard of hearing Classification and external resources The International Symbol for Deafness …
74Headphones — For other uses, see Headphones (disambiguation). Sennheiser HD555 headphones, used in audio production environments …
75Solar thermal energy — Solar thermal system for water heating in Santorini, Greece …
76Delta-sigma modulation — Delta sigma (ΔΣ; or sigma delta, ΣΔ) modulation is a method for encoding high resolution or analog signals into lower resolution digital signals. The conversion is done using error feedback, where the difference between the two signals is… …
77Auditory brainstem response — The auditory brainstem response (ABR) is an auditory evoked potential extracted from ongoing electrical activity in the brain and recorded via electrodes placed on the scalp. The resulting recording is a series of vertex positive waves of which I …
78electromagnetic radiation — Physics. radiation consisting of electromagnetic waves, including radio waves, infrared, visible light, ultraviolet, x rays, and gamma rays. [1950 55] * * * Energy propagated through free space or through a material medium in the form of… …
79climate change — Introduction periodic modification of Earth s climate brought about as a result of changes in the atmosphere as well as interactions between the atmosphere and various other geologic, chemical, biological, and geographic factors within the Earth …
80Copper wire and cable — Copper has been used in electric wiring since the invention of the electromagnet and the telegraph in the 1820s.[1][2] The invention of the telephone in 1876 proved to be another early boon for copper wire.[3] Today, despite competition from… …
