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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.
Highest ultraviolet index measured: On 29 December 2003, a UV index of 43.3 was detected at Chile/Bolivia's Licancabur volcano, at 19,423 feet (5,920 m) altitude. A light-skinned individual in such conditions may experience moderate sunburn in as little as 4 minutes.
Consider the sunburn, a deterministic effect: [4] when exposed to bright sunlight for only ten minutes [5] at a high UV Index, that is to say a high average dose rate, [6] the skin can turn red and painful. The same total amount of energy from indirect sunlight spread out over several years - a low average dose rate - would not cause a sunburn ...
The WHO-standard ultraviolet index is a widely publicized measurement of total strength of UV wavelengths that cause sunburn on human skin, by weighting UV exposure for action spectrum effects at a given time and location. This standard shows that most sunburn happens due to UV at wavelengths near the boundary of the UVA and UVB bands.
On the positive side, UV exposure enables the synthesis of vitamin D 3, which is essential for bone health [1] and potentially plays a role in inhibiting certain cancers. [ 2 ] [ 3 ] While vitamin D can also be obtained through dietary supplements, [ 4 ] UV exposure offers benefits such as enhanced subdermal nitric oxide production and improved ...
The refractive index of water at 20 °C for visible light is 1.33. [1] The refractive index of normal ice is 1.31 (from List of refractive indices).In general, an index of refraction is a complex number with real and imaginary parts, where the latter indicates the strength of absorption loss at a particular wavelength.
Extreme ultraviolet composite image of the Sun (red: 21.1 nm, green: 19.3 nm, blue: 17.1 nm) taken by the Solar Dynamics Observatory on August 1, 2010 13.5 nm extreme ultraviolet light is used commercially for photolithography as part of the semiconductor fabrication process.
Standard refractive index measurements are taken at the "yellow doublet" sodium D line, with a wavelength (λ) of 589 nanometers. There are also weaker dependencies on temperature , pressure / stress , etc., as well on precise material compositions (presence of dopants , etc.); for many materials and typical conditions, however, these ...