|
Nightlight
A nightlight is a small light fixture, usually electrical, placed for comfort or convenience in dark areas or areas that may become dark at certain times, such as at night or during an emergency. Small long-burning candles serving a similar function are referred to as "tealights". Uses and cultures People usually use nightlights for the sense of security which having a light on provides, or to relieve fear of the dark, especially in young children. Nightlights are also useful to the general public by revealing the general layout of a room without requiring a major light to be switched on, for avoiding tripping over stairs, obstacles, or pets, or to mark an emergency exit. Exit signs often use tritium radioluminescence. Homeowners usually place nightlights in bathrooms, kitchens and hallways to avoid turning on the main light fixture, especially late at night, and causing their eyes to adjust to the brighter light. Some frequent travelers carry small nightlights for temporary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NightLight
A nightlight is a small light fixture, usually electrical, placed for comfort or convenience in dark areas or areas that may become dark at certain times, such as at night or during an emergency. Small long-burning candles serving a similar function are referred to as "tealights". Uses and cultures People usually use nightlights for the sense of security which having a light on provides, or to relieve fear of the dark, especially in young children. Nightlights are also useful to the general public by revealing the general layout of a room without requiring a major light to be switched on, for avoiding tripping over stairs, obstacles, or pets, or to mark an emergency exit. Exit signs often use tritium radioluminescence. Homeowners usually place nightlights in bathrooms, kitchens and hallways to avoid turning on the main light fixture, especially late at night, and causing their eyes to adjust to the brighter light. Some frequent travelers carry small nightlights for temporary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fear Of The Dark
Fear of the dark is a common fear or phobia among children and, to a varying degree, adults. A fear of the dark does not always concern darkness itself; it can also be a fear of possible or imagined dangers concealed by darkness. Some degree of fear of the dark is natural, especially as a phase of child development. Most observers report that fear of the dark seldom appears before the age of two years. When fear of the dark reaches a degree that is severe enough to be considered pathological, it is sometimes called scotophobia (from – "darkness"), or lygophobia (from – "twilight"). Some researchers, beginning with Sigmund Freud, consider the fear of the dark to be a manifestation of separation anxiety disorder. An alternate theory was posited in the 1960s, when scientists conducted experiments in a search for molecules responsible for memory. In one experiment, rats, normally nocturnal animals, were conditioned to fear the dark and a substance called "scotophobin" was s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Fixture
A light fixture (US English), light fitting (UK English), or luminaire is an electrical device containing an electric lamp that provides illumination. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets for easy replacement—or, in the case of some LED fixtures, hard-wired in place. Fixtures may also have a switch to control the light, either attached to the lamp body or attached to the power cable. Permanent light fixtures, such as dining room chandeliers, may have no switch on the fixture itself, but rely on a wall switch. Fixtures require an electrical connection to a power source, typically AC mains power, but some run on battery power for camping or emergency lights. Permanent lighting fixtures are directly wired. Movable lamps have a plug and cord that plugs into a wall socket. Light fixtures may also have other features, such as reflectors for directing the light, an aperture (with or without a lens), an outer shell or housing f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LED Nightlight With Switch
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs, and in seven-segment displays. Later developments produced LEDs available in visible, ultraviolet (UV), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photocell
Photodetectors, also called photosensors, are sensors of light or other electromagnetic radiation. There is a wide variety of photodetectors which may be classified by mechanism of detection, such as photoelectric or photochemical effects, or by various performance metrics, such as spectral response. Semiconductor-based photodetectors typically photo detector have a p–n junction that converts light photons into current. The absorbed photons make electron–hole pairs in the depletion region. Photodiodes and photo transistors are a few examples of photo detectors. Solar cells convert some of the light energy absorbed into electrical energy. Types Photodetectors may be classified by their mechanism for detection: * Photoemission or photoelectric effect: Photons cause electrons to transition from the conduction band of a material to free electrons in a vacuum or gas. * Thermal: Photons cause electrons to transition to mid-gap states then decay back to lower bands, inducing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WebMD
WebMD is an American corporation known primarily as an online publisher of news and information pertaining to human health and well-being. The site includes information pertaining to drugs. It is one of the top healthcare websites. It was founded in 1998 by internet entrepreneur Jeff Arnold. In early 1999, it was part of a three way merger with Sapient Health Network (SHN) and Direct Medical Knowledge (DMK). SHN began in Portland, Oregon, in 1996 by Jim Kean, Bill Kelly, and Kris Nybakken, who worked together at a CD-ROM publishing firm, Creative Multimedia. Later in 1999, WebMD merged with Healtheon, founded by Netscape Communications founder James H. Clark. Traffic During March 2020, WebMD's network of websites reached more unique visitors each month than any other leading private or government healthcare website, making it the leading health publisher in the United States. In the fourth quarter of 2016, WebMD recorded an average of 179.5 million unique users per month, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabetic Retinopathy
Diabetic retinopathy (also known as diabetic eye disease), is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries. Diabetic retinopathy affects up to 80 percent of those who have had both type 1 and type 2 diabetes for 20 years or more. In at least 90% of new cases, progression to more aggressive forms of sight threatening retinopathy and maculopathy could be reduced with proper treatment and monitoring of the eyes The longer a person has diabetes, the higher his or her chances of developing diabetic retinopathy. Each year in the United States, diabetic retinopathy accounts for 12% of all new cases of blindness. It is also the leading cause of blindness in people aged 20 to 64. Signs and symptoms Nearly all people with diabetes develop some degree of retina damage ("retinopathy") over several decades with the disease. For many, that damage can only be detected by a retinal exam, and has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 ''Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science Daily
''Science Daily'' is an American website launched in 1995 that aggregates press releases and publishes lightly edited press releases (a practice called churnalism) about science, similar to Phys.org and EurekAlert!. The site was founded by married couple Dan and Michele Hogan in 1995; Dan Hogan formerly worked in the public affairs department of Jackson Laboratory writing press releases. The site makes money from selling advertisements. As of 2010, the site said that it had grown "from a two-person operation to a full-fledged news business with worldwide contributors". At the time, it was run out of the Hogans' home, had no reporters, and only reprinted press releases. In 2012, Quantcast Quantcast is an American technology company, founded in 2006, that specializes in AI-driven real-time advertising, audience insights and measurement. It has offices in the United States, Canada, Australia, Singapore, United Kingdom, Ireland, Fran ... ranked it at 614 with 2.6 million U.S. vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohio State University
The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best public universities in the United States. Founded in 1870 as the state's land-grant university and the ninth university in Ohio with the Morrill Act of 1862, Ohio State was originally known as the Ohio Agricultural and Mechanical College and focused on various agricultural and mechanical disciplines, but it developed into a comprehensive university under the direction of then-Governor and later U.S. president Rutherford B. Hayes, and in 1878, the Ohio General Assembly passed a law changing the name to "the Ohio State University" and broadening the scope of the university. Admission standards tightened and became greatly more selective throughout the 2000s and 2010s. Ohio State's political science department and faculty have greatly contri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Association For The Advancement Of Science
The American Association for the Advancement of Science (AAAS) is an American international non-profit organization with the stated goals of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsibility, and supporting scientific education and science outreach for the betterment of all humanity. It is the world's largest general scientific society, with over 120,000 members, and is the publisher of the well-known scientific journal ''Science''. History Creation The American Association for the Advancement of Science was created on September 20, 1848, at the Academy of Natural Sciences in Philadelphia, Pennsylvania. It was a reformation of the Association of American Geologists and Naturalists. The society chose William Charles Redfield as their first president because he had proposed the most comprehensive plans for the organization. According to the first constitution which was agreed to at the September 20 meeting, the goal of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nearsightedness
Near-sightedness, also known as myopia and short-sightedness, is an eye disease where light focuses in front of, instead of on, the retina. As a result, distant objects appear blurry while close objects appear normal. Other symptoms may include headaches and eye strain. Severe near-sightedness is associated with an increased risk of retinal detachment, cataracts, and glaucoma. The underlying mechanism involves the length of the eyeball growing too long or less commonly the lens being too strong. It is a type of refractive error. Diagnosis is by eye examination. Tentative evidence indicates that the risk of near-sightedness can be decreased by having young children spend more time outside. This decrease in risk may be related to natural light exposure. Near-sightedness can be corrected with eyeglasses, contact lenses, or a refractive surgery. Eyeglasses are the easiest and safest method of correction. Contact lenses can provide a wider field of vision, but are associated with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Ohio State University")
