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UV light comes from the sun and is transmitted in waves or particles at different wavelengths an frequencies.
It makes black-light posters glow, and is responsible for summer tans. But too much exposure to UV radiation damage living tissue.
EM is the broad range of wavelengths. It is divided into seven regions and ordered in decreasing wavelength and increasing energy and frequency, namely radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma-rays.
Ultraviolet light falls is the range of the EM spectrum between visible light and X-rays.
UV radiation has enough energy to break chemical bonds. UV photons can cause ionization, meaning chemical bonds will break that otherwise would not.
It can be useful, for instance, in disinfecting a surface, but it can also damage materials and living tissues, particularly the skin and eyes that are affected by UVB and UVC radiation.
Most natural UV light comes from the sun. Only 10 % of sunlight is UV, and only one-third of it gets through the atmosphere.
Of the solar UV energy that reaches the equator, 95% is UVA, and 5% is UVB. No measurable UVC from the sun gets to the Earth's surface, because ozone, molecular oxygen, and water vapour in the upper atmosphere absorb the shortest UV wavelengths.
A suntan is a reaction to exposure to UVB rays. When the body senses sun damage, it sends melanin, a pigment in the body, to absorb UV light and protect the body from more damage, resulting in a darkened skin.
Continued exposure to UV radiation can damage the body's DNA. When the body senses this destruction, it floods the area with blood and inflammation to help with the healing process. Sometimes the cells with DNA mutated by the sun's rays turn into problem cells, known as skin cancer.
Substances like minerals, plants, fungi, microbes, and organic and inorganic chemicals, can absorb UV radiation, causing electrons to jump to a higher energy level. When the electrons return to a lower energy level, they emit a portion of the absorbed energy as visible light.
There are also other celestial sources of UV radiation.
Very large young stars shine most of their light in ultraviolet wavelengths. But the Earth's atmosphere blocks much of the UV radiation, and observations are conducted using high-altitude balloons and special orbiting telescopes equipped to observe the UV region of the EM spectrum.
Some skin conditions can be treated using UV light.
PUVA (psoralen ultraviolet light treatment) is used to treat lymphoma, eczema, psoriasis, and vitiligo. Patients take a drug or apply a lotion to make their skin sensitive to light. Then a UV light is shone on the skin, slowing down the growth of the skin cells.
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There's a lot of similarity between people who experience misophonia, but also a lot of diversity.
Therapists use a variety of techniques that is often based on the symptoms. Those who experience fear and anxiety may respond to exposure-based treatments. Those who experience anger can learn to manage their distress through distraction or relaxation techniques.
Refrigeration is the action of creating cooling conditions by removing heat. It is used for preserving food by slowing bacteria growth.
Refrigerators today work by evaporating liquids.
The liquids are pushed through the refrigerator through tubes and begin to vaporize. As the liquids evaporate, they carry heat away with them as the gases travel to a coil outside the refrigerator. Here the heat is released. The gases return to a compressor, where they become liquid again, restarting the cycle.