active region


Also found in: Acronyms.

active region

[′ak·tiv ′rē·jən]
(astronomy)
A localized, transient, nonuniform region on the sun's surface, penetrating well down into the lower chromosphere.
(electronics)
The region in which amplifying, rectifying, light emitting, or other dynamic action occurs in a semiconductor device.
References in periodicals archive ?
Recent observation of hard X-ray spectra of an active region has given an upper limit to the amount of hot (T > 8 MK) component (38) and also constrains the property of the small-scale events.
Therefore, the active region that made of quantum well (QW) has been successfully utilized to optical fiber communication applications.
New Zealand is part of a geologically active region that's often called the Pacific "Ring of Fire," an arc of volcanoes and fault lines in the Pacific Basin.
Moreover, self-heating is reduced by optical pumping to inject carriers directly into the active region, resulting in increased output power and lower operating temperature [6].
While the active region 11087 was situated on the northeast disk, PROBA2 experienced a solar eclipse on July 11, 2010.
In recent times, while Europe has been the most active region in terms of deal volume, North America has been the most active region when it comes to deal value.
The channels remained hidden because the once volcanically active region had been filled in by lava flows hundreds of millions years ago.
On 2012 July 12 a long-duration X1.4 solar flare erupted from Active Region 1520, commencing at 15:37 UTC and reaching maximum X-ray emission levels at 16:49 (data from NOAA SWPC SDF report 193).
* Europe remained the most active region, accounting for 48 percent of total launches, followed by Asia Pacific, with 22 percent.
He further reminded of the potential risk the project would have posed, as the nuclear power plant was to be built in a seismically active region.
Also, Iran's only ''purely civilian'' installation, the Bushehr power plant, will come under closer scrutiny: it is located in a seismically active region and is a dubious mix of German and Russian technologies.
Manhattan was the most active region in apartment building trades last year, followed by Brooklyn and then the Bronx, a new report released today from Ariel Property Advisors shows (see full report below).

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