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Photokeratitis
Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet (UV) rays from either natural (e.g. intense sunlight) or artificial (e.g. the electric arc during welding) sources. Photokeratitis is akin to a sunburn of the cornea and conjunctiva. The injury may be prevented by wearing eye protection that blocks most of the ultraviolet radiation, such as welding goggles with the proper filters, a welder's helmet, sunglasses rated for sufficient UV protection, or appropriate snow goggles. The condition is usually managed by removal from the source of ultraviolet radiation, covering the corneas, and administration of pain relief. Photokeratitis is known by a number of different terms including: snow blindness, arc eye, welder's flash, bake eyes, corneal flash burns, flash burns, niphablepsia, or keratoconjunctivitis photoelectrica. Signs and symptoms Common symptoms include pain, intense tears, eyelid tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from 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 energy to ionization, ionize atoms, it can cause chemical reactions and causes many substances to glow or fluorescence, fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UV Rays
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from 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 energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. For hum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tanning Beds
Indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. Typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a horizontal tanning bed, also known as a sunbed or solarium. Vertical devices are known as tanning booths or stand-up sunbeds. First introduced in the 1960s, indoor tanning became popular with people in the Western world, particularly in Scandinavia, in the late 1970s. The practice finds a cultural parallel in skin whitening in Asian countries, and both support multibillion-dollar industries. Most indoor tanners are women, 16–25 years old, who want to improve their appearance or mood, acquire a pre-holiday tan, or treat a skin condition.Hay and Lipsky (2012), 181–184. Across Australia, Canada, Northern Europe and the United States, 18.2% of adults, 45.2% of university students, and 22% of adolescents had tanned indoors in the previous ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunglasses
Sunglasses or sun glasses (informally called shades or sunnies; more names below) are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are colored, polarized or darkened. In the early 20th century, they were also known as sun cheaters (cheaters then being an American slang term for glasses). Since the 1930s, sunglasses have been a popular fashion accessory, especially on the beach. The American Optometric Association recommends wearing sunglasses that block ultraviolet radiation (UV) whenever a person is in the sunlight to protect the eyes from UV and blue light, which can cause several serious eye problems. Their usage is mandatory immediately after some surgical procedures, such as LASIK, and recommended for a certain time period in dusty areas, when leaving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inuit Snow Goggles
Snow goggles (Inuktitut: or , syllabics: or ; esu, nigaugek, ) are a type of eyewear traditionally used by the Inuit and the Yupik peoples of the Arctic to prevent snow blindness. The goggles fit tightly against the face so that the only light entering is through the slits, and soot is sometimes applied to the inside to help cut down on glare. The slits are made narrow not only to reduce the amount of light entering but also to improve the visual acuity. Wider slits result in a larger field of view. Terminology Like other Inuit language words, such as inukhuk/inuksuk, a different word may be used in different dialects. In the Kivalliq dialect, () is used, while the North Baffin dialect uses (). Both words are also used to refer to sunglasses. In Central Yup'ik, snow goggles are called , while in Cup'ig they are ''igguag''. In Siberian Yupik, the word is . See also * Pinhole glasses References {{DEFAULTSORT:Inuit Snow Goggles Goggles Snow goggles Snow goggles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Welding Goggles
Welding goggles provide a degree of eye protection while some forms of welding and cutting are being done. They are intended to protect the eyes not only from the heat and optical radiation produced by the welding, such as the intense ultraviolet light produced by an electric arc, but also from sparks or debris. A full facemask may be required for arc welding. Welding and cutting processes, including arc welding and cutting, as well as brazing produce intense ultraviolet (UV), infrared (IR) and visible light wavelengths. The UV and IR wavelengths cannot be seen and can produce eye injury without the victim realizing it immediately. Extremely dark filters of the proper sort are needed for the welder to be able to look at the intensely glowing metal being welded. An approved face shield or welding helmet can also have filters for optical radiation protection, and offer additional protection against debris and sparks. UV blocking protective spectacles with side shields or welding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snow Goggles
Snow goggles (Inuktitut: or , syllabics: or ; esu, nigaugek, ) are a type of eyewear traditionally used by the Inuit and the Yupik peoples of the Arctic to prevent snow blindness. The goggles fit tightly against the face so that the only light entering is through the slits, and soot is sometimes applied to the inside to help cut down on glare. The slits are made narrow not only to reduce the amount of light entering but also to improve the visual acuity. Wider slits result in a larger field of view. Terminology Like other Inuit language words, such as inukhuk/inuksuk, a different word may be used in different dialects. In the Kivalliq dialect, () is used, while the North Baffin dialect uses (). Both words are also used to refer to sunglasses. In Central Yup'ik, snow goggles are called , while in Cup'ig they are ''igguag''. In Siberian Yupik, the word is . See also * Pinhole glasses References {{DEFAULTSORT:Inuit Snow Goggles Goggles Snow goggles Snow goggles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Peoples
Circumpolar peoples and Arctic peoples are umbrella terms for the various Indigenous peoples of the Arctic. Prehistory The earliest inhabitants of North America's central and eastern Arctic are referred to as the Arctic small tool tradition (AST) and existed c. 2500 BC. AST consisted of several Paleo-Eskimo cultures, including the Independence cultures and Pre-Dorset culture.Gibbon, pp. 28–31 The Dorset culture (Inuktitut: ''Tuniit'' or ''Tunit'') refers to the next inhabitants of central and eastern Arctic. The Dorset culture evolved because of technological and economic changes during the period of 1050–550 BC. With the exception of the Quebec/Labrador peninsula, the Dorset culture vanished around 1500 AD. Dorset/Thule culture transition dates around the 9th–10th centuries. Scientists theorize that there may have been cross-contact of the two cultures with sharing of technology, such as fashioning harpoon heads, or the Thule may have found Dorset remnants and adapted thei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Height Above Sea Level
Height above mean sea level is a measure of the vertical distance (height, elevation or altitude) of a location in reference to a historic mean sea level taken as a vertical datum. In geodesy, it is formalized as ''orthometric heights''. The combination of unit of measurement and the physical quantity (height) is called "metres above mean sea level" in the metric system, while in United States customary and imperial units it would be called "feet above mean sea level". Mean sea levels are affected by climate change and other factors and change over time. For this and other reasons, recorded measurements of elevation above sea level at a reference time in history might differ from the actual elevation of a given location over sea level at a given moment. Uses Metres above sea level is the standard measurement of the elevation or altitude of: * Geographic locations such as towns, mountains and other landmarks. * The top of buildings and other structures. * Flying objects such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yupik Peoples
The Yupik (plural: Yupiit) (; russian: Юпикские народы) are a group of indigenous or aboriginal peoples of western, southwestern, and southcentral Alaska and the Russian Far East. They are related to the Inuit and Iñupiat. Yupik peoples include the following: * Alutiiq, or Sugpiaq, of the Alaska Peninsula and coastal and island areas of southcentral Alaska. * Yup'ik or Central Alaskan Yup'ik of the Yukon–Kuskokwim Delta, the Kuskokwim River, and along the northern coast of Bristol Bay as far east as Nushagak Bay and the northern Alaska Peninsula at Naknek River and Egegik Bay in Alaska. * Siberian Yupik, including Naukan, Chaplino,Achirgina-Arsiak, Tatiana"Northeastern Siberian: Yupik (Asiatic Eskimo)."''Alaska Native Collections.'' 1996. Retrieved 20 July 2012. and — in a linguistic capacity — the Sirenik of the Russian Far East and St. Lawrence Island in western Alaska. Population The Yup'ik are by far the most numerous of the various Alaska Native gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inuit
Inuit (; iu, ᐃᓄᐃᑦ 'the people', singular: Inuk, , dual: Inuuk, ) are a group of culturally similar indigenous peoples inhabiting the Arctic and subarctic regions of Greenland, Labrador, Quebec, Nunavut, the Northwest Territories, and Alaska. Inuit languages are part of the Eskimo–Aleut languages, also known as Inuit-Yupik-Unangan, and also as Eskaleut. Inuit Sign Language is a critically endangered language isolate used in Nunavut. Inuit live throughout most of Northern Canada in the territory of Nunavut, Nunavik in the northern third of Quebec, Nunatsiavut and NunatuKavut in Labrador, and in various parts of the Northwest Territories, particularly around the Arctic Ocean, in the Inuvialuit Settlement Region. With the exception of NunatuKavut, these areas are known, primarily by Inuit Tapiriit Kanatami, as Inuit Nunangat. In Canada, sections 25 and 35 of the Constitution Act of 1982 classify Inuit as a distinctive group of Aboriginal Canadians wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Driftwood
__NOTOC__ Driftwood is wood that has been washed onto a shore or beach of a sea, lake, or river by the action of winds, tides or waves. In some waterfront areas, driftwood is a major nuisance. However, the driftwood provides shelter and food for birds, fish and other aquatic species as it floats in the ocean. Gribbles, shipworms and bacteria decompose the wood and gradually turn it into nutrients that are reintroduced to the food web A food web is the natural interconnection of food chains and a graphical representation of what-eats-what in an ecological community. Another name for food web is consumer-resource system. Ecologists can broadly lump all life forms into one o .... Sometimes, the partially decomposed wood washes ashore, where it also shelters birds, plants, and other species. Driftwood can become the foundation for sand dunes. Most driftwood is the remains of trees, in whole or part, that have been washed into the ocean, due to flooding, high winds, or ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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