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Halogen lamps with fused quartz envelopes are used as inexpensive UV light sources in the near UV range, from 400 to 300 nm, in some scientific instruments. Due to its black-body spectrum a filament light bulb is a very inefficient ultraviolet source, emitting only a fraction of a percent of its energy as UV, as explained by the black body ...
In frequency (and thus energy), UV rays sit between the violet end of the visible spectrum and the X-ray range. The UV wavelength spectrum ranges from 399 nm to 10 nm and is divided into 3 sections: UVA, UVB, and UVC. UV is the lowest energy range energetic enough to ionize atoms, separating electrons from them, and thus causing chemical reactions.
Sunburn effect (as measured by the UV index) is the product of the sunlight power spectrum (radiation intensity) and the erythemal action spectrum (skin sensitivity) across the range of UV wavelengths. [9] [10] The UV index is a number linearly related to the intensity of sunburn-producing UV radiation at a given point on the Earth's surface.
Optical radiation is the part of the electromagnetic spectrum with wavelengths between 100 nm and 1 mm. [1] [2] This range includes visible light, infrared light, and part of the ultraviolet spectrum. [3] Optical radiation is non-ionizing, [4] and can be focused with lenses and manipulated by other optical elements.
There is little radiation flux (in terms of W/m 2) to the Earth's surface below 0.2μm or above 3.0μm, although photon flux remains significant as far as 6.0μm, compared to shorter wavelength fluxes. UV-C radiation spans from 0.1μm to .28μm, UV-B from 0.28μm to 0.315μm, UV-A from 0.315μm to 0.4μm, the visible spectrum from 0.4μm to 0 ...
“Lasers use a very specific wavelength of light, rather than a broad wavelength,” says dermatologist Shari Lipner, MD. “If we’re treating broken blood vessels, for example, we’d use a ...
The visible range of most animals evolved to match the optical window, which is the range of light that can pass through the atmosphere. The ozone layer absorbs almost all UV light (below 315 nm). [19] However, this only affects cosmic light (e.g. sunlight), not terrestrial light (e.g. Bioluminescence).
A FBI document obtained by Wikileaks details the symbols and logos used by pedophiles to identify sexual preferences. According to the document members of pedophilic organizations use of ...