Any content on the subject welcome.
Many natural and synthetic polymers are attacked by ultraviolet radiation, and products using these materials may crack or disintegrate if they are not UV-stable. The problem is known as UV degradation, and is a common problem in products exposed to sunlight. Continuous exposure is a more serious problem than intermittent exposure, since attack is dependent on the extent and degree of exposure.
Many pigments and dyes can also be affected, and the problem known as phototendering can affect textil...
Solar irradiance (SI) is the power per unit area (watts per square metre, W/m2), received from the Sun in the form of electromagnetic radiation as reported in the wavelength range of the measuring instrument.
Solar irradiance is often integrated over a given time period in order to report the radiant energy emitted into the surrounding environment (joules pet square metre, J/m2), during that time period. This integrated solar irradiance is called solar irradiation, solar exposure, solar insolati...
Ultraviolet (UV) designates a band of the electromagnetic spectrum with wavelength from 10Â nm to 400Â nm, shorter than that of visible light but longer than X-rays. UV radiation is present in sunlight, and contributes about 10% of the total light output of the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the ene...
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Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is filtered through Earth's atmosphere, and is obvious as daylight when the Sun is above the horizon. When the direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When it is blocked by clouds or reflects off other objects, it is experienced as diffused light. The World Met...
Sunshine duration or sunshine hours is a climatological indicator, measuring duration of sunshine in given period (usually, a day or a year) for a given location on Earth, typically expressed as an averaged value over several years. It is a general indicator of cloudiness of a location, and thus differs from insolation, which measures the total energy delivered by sunlight over a given period.
Sunshine duration is usually expressed in hours per year, or in (average) hours per day. The first meas...
https://globalsolaratlas.info/?m=sg:dni
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The good news is that anti-UV fabric protection is quite effective if applied and maintained properly. Aircraft fabric can last well over a decade outdoors, while still meeting specified performance.
This is a prolific Old Forum topic to mine; polymer-by-polymer, treatment-by-treatment. There are a few hidden lessons, like how a protection coat may crack if it is not renewed, or if the base fabric stretches too much, and the UV damage then proceeds in the cracks.
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Tom
April 23, 2019, 10:01am
4
kitefreak:
This is a prolific Old Forum topic to mine; polymer-by-polymer, treatment-by-treatment. There are a few hidden lessons, like how a protection coat may crack if it is not renewed, or if the base fabric stretches too much, and the UV damage then proceeds in the cracks.
Is there any collection of that knowledge? (and don’t say: Just look in the old forum)
https://groups.yahoo.com/neo/groups/AirborneWindEnergy/conversations/messages/22257
