Ultraviolet Light-
Ultraviolet light or UV light is radiation with a higher frequency than violet light. The sun yet again, posseses another property along side infared and visible light. Our bodies need some exposure to UV rays to produce Vitamin D.
Although we cannot see Ultraviolet light, it can tan or burn your skin. High amounts of exposure to this type of radiation can result in cancers such as melanoma. UV rays can also cause you to develop cataracts in your eyes. Polarised glasses and sunscreen can help prevent the harmful effects of UV light. Some substances fluoresce when hit by ultraviolet light. This means they absorb and emit visible light. White paper, teeth whiteners and some laundry powders make use of this asset to make paper, teeth or clothes appear brighter. UV light can also be used to sterilise objects. The wavelegth are in the range of 10 nm to 400 nm, and frequencies of about 800 THz to 30 PHz. Ionisation UV radiation has enough energy to break chemical bonds. Due to their higher energies, UV photons can cause ionisation, a process in which electrons break away from atoms. This affects the chemical properties of the atoms and causes them to form or break chemical bonds that they normally would not. It can be useful for chemical processing, or it can be damaging to living tissues and some materials. The most common form of ionising damage incurred by humans is sunburn, although UV rays will burn through a cornea if allowed. Furthermore, long term exposure to UV has also been linked to numerous forms of skin cancer. This damage can be beneficial, when disinfecting surfaces, but it can also be harmful, especially to the skin and eyes, which are most affected by higher-energy UVB and UVC radiation. |
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In today's society we use:
UV Disinfection of Bugs and Microorganisms There is a certain wavelength at which bugs, viruses and pathogens become zapped. All you need is anultraviolet light, that is radiating out at a wavelength of 265 nanometres, then DNA structure of the microorganism becomes dormant. Doctors have only recently turned to this method of treating bugs as the UV rays penetrate cellular walls and disrupt DNA replication, fundamentally preventing the cell from replicating or repairing itself, ultimately rendering it harmless if not outright dead. There are two primary means of producing UV light in these two frequencies — continuous mercury vapour UV lamps and pulse xenon UV. Although, the former provides harmful toxic gasses and energy ineffcient. In addition to large amounts of hand sanitizer, hospitals in America are now turning to devices like the UV emitter from Xenex Healthcare Services. |