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An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the ...
Nūr (Arabic: النور) is a term in Islamic context referring to the "cold light of the night" or "heatless light" i.e. the light of the moon. This light is used as a symbol for "God's guidance" and "knowledge", a symbol of mercy in contrast to Nar, which refers to the diurnal solar "hot light" i.e. fire. [1] In the Quran, God is stated to be "the light (Nūr) of the heavens and the earth ...
A nightlight is a small light fixture, usually electrical, placed for comfort or convenience in dark areas or areas that may become dark at certain times, such as at night or during an emergency. Small long-burning candles serving a similar function are referred to as "tealights".
If light sources (e.g. the Moon and light pollution) were removed from the night sky, only direct starlight would be visible. The sky's brightness varies greatly over the day, and the primary cause differs as well. During daytime, when the Sun is above the horizon, the direct scattering of sunlight is the
Auto-yokes" are often promoted as a way to modernize and increase the flexibility of an inventory of lighting fixtures at a reduced cost to replacement with intelligent lights. Generally, moving mirrors are faster at adjusting a lights position than moving head fixtures; however, moving-heads-style fixtures have a far larger total range of ...
Civil, nautical, and astronomical twilight. [3] Dusk is the darkest part of evening twilight. The time of dusk is the moment at the very end of astronomical twilight, just before the minimum brightness of the night sky sets in, or may be thought of as the darkest part of evening twilight. [4]
The major advantage of a lighting control system over stand-alone lighting controls or conventional manual switching is the ability to control individual lights or groups of lights from a single user interface device.
Shab-e-Barat (lit. ' Barat Night '), Cheragh-e-Barat, Berat Kandili, or Nisfu Syaaban (Southeastern Asian Muslims) is a Mid-Sha'ban related cultural celebration celebrated in many South Asian, Central Asian, South East Asian and Middle Eastern Muslim countries, on the 15th night (the night on 15th only) of the month of Sha'ban, the eighth month of the Islamic calendar.