|
Arc Eye
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 direct or reflected 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, sand eyes, bake eyes, corneal flash burns, flash burns, niphablepsia, or keratoconjunctivitis photoelectrica. Signs and symptoms Common symptoms include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Eye
The human eye is a sensory organ in the visual system that reacts to light, visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and Balance (ability), keeping balance. The eye can be considered as a living optics, optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially stray light, light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea, cornea—the clear part of the eye) that accounts for most of the optical power of the eye and accomplishes most of the Focus (optics), focusing of light from the outside world; then an aperture (the pupil) in a Diaphragm (optics), diaphragm (the Iris (anatomy), iris—the coloured part of the eye) that controls the amount of light entering the interior of the eye; then an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indoor Tanning
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. Once the connection between indoor tanning and skin cancer was confirmed, the number and use of indoor tanning facilities have declined, and many countries have either ban ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antler
Antlers are extensions of an animal's skull found in members of the Cervidae (deer) Family (biology), family. Antlers are a single structure composed of bone, cartilage, fibrous tissue, skin, nerves, and blood vessels. They are generally found only on males, with the exception of Reindeer, reindeer/caribou. Antlers are Moulting, shed and regrown each year and function primarily as objects of sexual attraction and as Weapon (biology), weapons. Etymology Antler comes from the Old French ''antoillier ''(see present French : "Andouiller", from'' ant-, ''meaning before,'' oeil, ''meaning eye and'' -ier'', a suffix indicating an action or state of being) possibly from some form of an unattested Latin word ''*anteocularis'', "before the eye" (and applied to the word for "branch" or "horn (anatomy), horn"). Structure and development Antlers are unique to cervids. The ancestors of deer had tusks (long upper canine tooth, canine teeth). In most species, antlers appear to replace t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Driftwood
Driftwood is a wood that has been washed onto a shore or beach of a sea, lake, or river by the action of winds, tides or waves. It is part of beach wrack. 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. 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 other natural occurrences, or as the result of logging. There is also a subset of driftwood known as drift lumber. Drift lumber includes the remains of man-made wooden objects, such as buildings and their contents washed into the sea duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snow Goggles
Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout its life cycle, starting when, under suitable conditions, the ice crystals form in the atmosphere, increase to millimeter size, precipitate and accumulate on surfaces, then metamorphose in place, and ultimately melt, slide, or Sublimation (phase transition), sublimate away. Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes Nucleation, nucleate around particles in the atmosphere by attracting supercooling, supercooled water droplets, which Freezing, freeze in hexagonal-shaped crystals. Snowflakes take on a variety of shapes, basic among these are platelets, needles, columns, and Hard rime, rime. As snow accumulates into a snowpack, it may blow into drifts. Over time, accumulated snow m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumpolar Peoples
Circumpolar peoples and Arctic peoples are umbrella terms for the various indigenous peoples of the Arctic region. Approximately four million people are resident in the Arctic, among which 10 percent are indigenous peoples belonging to a vast number of distinct communities. They represent a minority with the exception of Greenland of which 90 percent of its population is composed of Inuit. It is difficult to find an exact number of the indigenous peoples in the Arctic as states have a tendency to downplay the numbers. Moreover, each state has its own different methods to count its indigenous population. For instance, Russia excludes from the official status of "small peoples of the North" ( or ) every community that exceeds 50,000 people. They are therefore excluding from the definition certain numerically large indigenous communities like the Komi peoples, Karelians or Yakuts. Prehistory The earliest inhabitants of North America's central and eastern Arctic are referred to as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yupik Peoples
The Yupik (; ) 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. * Yupʼik or Central Alaskan Yupʼik 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 Yupʼik people are by far the most numerous of the various Alaska Native groups. They speak the Central Alaskan Y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inuit
Inuit (singular: Inuk) are a group of culturally and historically similar Indigenous peoples traditionally inhabiting the Arctic and Subarctic regions of North America and Russia, including Greenland, Labrador, Quebec, Nunavut, the Northwest Territories, Yukon (traditionally), Alaska, and the Chukotsky District of Chukotka Autonomous Okrug. The Inuit languages are part of the Eskaleut languages, also known as Inuit-Yupik-Unangan, and also as Eskimo–Aleut. Canadian Inuit live throughout most of Northern Canada in the territory of Nunavut, Nunavik in the northern third of Quebec, the Nunatsiavut in Labrador, and in various parts of the Northwest Territories and Yukon (traditionally), particularly around the Arctic Ocean, in the Inuvialuit Settlement Region. These areas are known, by Inuit Tapiriit Kanatami and the Government of Canada, as Inuit Nunangat. In Canada, sections 25 and 35 of the Constitution Act of 1982 classify Inuit as a distinctive group of Abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunglasses
Sunglasses or sun glasses (informally called shades or sunnies; more names Sunglasses#Other names, below) are a form of Eye protection, 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, polarizer, polarized or darkened. In the early 20th century, they were also known as sun cheaters (cheaters then being an United States, 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 #Protection, serious eye problems. Their usage is mandatory immediately after some surgical procedures, such as L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inuit Snow Goggles
Inuit (singular: Inuk) are a group of culturally and historically similar Indigenous peoples traditionally inhabiting the Arctic and Subarctic regions of North America and Russia, including Greenland, Labrador, Quebec, Nunavut, the Northwest Territories, Yukon (traditionally), Alaska, and the Chukotsky District of Chukotka Autonomous Okrug. The Inuit languages are part of the Eskaleut languages, also known as Inuit-Yupik-Unangan, and also as Eskimo–Aleut. Canadian Inuit live throughout most of Northern Canada in the territory of Nunavut, Nunavik in the northern third of Quebec, the Nunatsiavut in Labrador, and in various parts of the Northwest Territories and Yukon (traditionally), particularly around the Arctic Ocean, in the Inuvialuit Settlement Region. These areas are known, by Inuit Tapiriit Kanatami and the Government of Canada, as Inuit Nunangat. In Canada, sections 25 and 35 of the Constitution Act of 1982 classify Inuit as a distinctive group of Aboriginal Canadi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescein
Fluorescein is an organic compound and dye based on the xanthene tricyclic structural motif, formally belonging to Triarylmethane dye, triarylmethine dyes family. It is available as a dark orange/red powder slightly soluble in water and alcohol. It is used as a fluorescent Flow tracer, tracer in many applications. The color of its aqueous solutions is green by reflection and orange by transmission (its spectral properties are dependent on pH of the solution), as can be noticed in spirit level, bubble levels, for example, in which fluorescein is added as a colorant to the Alcohol (chemistry), alcohol filling the tube in order to increase the visibility of the air bubble contained within. More concentrated solutions of fluorescein can even appear red (because under these conditions nearly all incident emission is re-absorbed by the solution). It is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. Uses Fluorescein sodium, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Height Above Mean Sea Level
Height above mean sea level is a measure of a location's vertical distance (height, elevation or altitude) in reference to a vertical datum based on a historic mean sea level. In geodesy, it is formalized as orthometric height. The zero level varies in different countries due to different reference points and historic measurement periods. Climate change and other forces can cause sea levels and elevations to vary over time. Uses Elevation or altitude above sea level is a standard measurement for: * Geographic locations such as towns, mountains and other landmarks. * The top of buildings and other structures. * Mining infrastructure, particularly underground. * Flying objects such as airplanes or helicopters below a Transition Altitude defined by local regulations. Units and abbreviations Elevation or altitude is generally expressed as "metres above mean sea level" in the metric system, or " feet above mean sea level" in United States customary and imperial units. Comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
