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  2. Ultraviolet - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet

    UV radiation is also produced by electric arcs. Arc welders must wear eye protection and cover their skin to prevent photokeratitis and serious sunburn . Ultraviolet radiation , also known as simply UV , is electromagnetic radiation of wavelengths of 10–400 nanometers , shorter than that of visible light , but longer than X-rays .

  3. Sunlight - Wikipedia

    en.wikipedia.org/wiki/Sunlight

    Extreme UV and X-rays are produced (left of wavelength range) but comprise very small amounts of the Sun's total output power (area under the curve). Although the solar corona is a source of extreme ultraviolet and X-ray radiation, these rays make up only a very small amount of the power output of the Sun (see spectrum at right).

  4. Optical window - Wikipedia

    en.wikipedia.org/wiki/Optical_window

    Solar irradiance spectrum above atmosphere and at surface. Extreme UV and X-rays are produced (at left of wavelength range shown) but comprise very small amounts of the Sun's total output power.

  5. Ultraviolet index - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet_index

    Average UV at noon 1996-2002 (European Space Agency) The ultraviolet index, or UV index, is an international standard measurement of the strength of the sunburn-producing ultraviolet (UV) radiation at a particular place and time. It is primarily used in daily and hourly forecasts aimed at the general public.

  6. Extreme ultraviolet - Wikipedia

    en.wikipedia.org/wiki/Extreme_ultraviolet

    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.

  7. How to Get Enough Vitamin D in The Winter, According to ... - AOL

    www.aol.com/enough-vitamin-d-winter-according...

    This happens when "UV rays convert a substance on our skin called 7-dehydrocholesterol into vitamin D. In order for vitamin D to do its job, it needs to be transformed into active vitamin D by the ...

  8. Ultraviolet germicidal irradiation - Wikipedia

    en.wikipedia.org/wiki/Ultraviolet_germicidal...

    UV radiation at 185 nm is used to generate ozone. The UV lamps for water treatment consist of specialized low-pressure mercury-vapor lamps that produce ultraviolet radiation at 254 nm, or medium-pressure UV lamps that produce a polychromatic output from 200 nm to visible and infrared energy. The UV lamp never contacts the water; it is either ...

  9. Radiation - Wikipedia

    en.wikipedia.org/wiki/Radiation

    A number of other high energy particulate radiations such as positrons, muons, and pions were discovered by cloud chamber examination of cosmic ray reactions shortly thereafter, and others types of particle radiation were produced artificially in particle accelerators, through the last half of the twentieth century.