Exoplanets are relatively faint, since they don't emit light by themselves.
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Really, almost anything that can be made to emit light will do.
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You need some sort of luciferin, a molecule that can emit light.
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True to its name, the material doesn't emit light, so we've never detected it directly.
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Because black holes don't emit light, these waves were invisible and only "heard" as thumps.
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The phenomenon of glowing water is caused by tiny plankton that emit light when agitated.
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Very exotic places that emit light of all kinds of colors in the whole spectrum.
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Such planets don't emit light, so gravitational microlensing is the only technique that can detect them.
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Yet it's incredibly mysterious: Because it doesn't emit light, no one has ever directly seen it.
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The lamps near the vanity collection emit light toward the ceiling, avoiding direct exposure to the face.
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These collisions "excite" the molecules in the atmosphere, and when these molecules release this energy, they emit light.
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These atoms are engineered to emit light waves that oscillate at a constant several billion times a second.
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Then the gas within the tube is heated to a temperature high enough to fluoresce and emit light.
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A good black level is so dark the point being measured does not seem to emit light at all.
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The objective behind getting neurons to emit light is to better observe activity in the brain's complex neural networks.
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But when that accretion rate drops, the disk puffs up into a quasi-spherical structure that struggles to emit light.
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Black holes, for example, do not emit light, radio waves and the like, but can be studied via gravitational waves.
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He cited early research into camouflaged wet suits and "counter-illumination" surfboards, whose undersides emit light to diminish their silhouette.
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According to CNET, those devices are unique because they have microscopic molecules that emit light when illuminated by an LED backlight.
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Engineers at Glasgow are therefore working on a laser optimised to emit light at the frequencies best suited for analysing mosquitoes.
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Ring lights emit light all around you while eliminating shadows from every direction, which is why they're regularly used by vloggers.
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Then, they beamed a pulsing laser at the antihydrogen, which caused the anti-atoms to emit light, whose colors they measured.
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Both of these emit light when excited by electricity, so wall coverings printed with such materials could be used to illuminate rooms.
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But because this form of matter does not emit light, researchers are literally left in the dark about most of its properties.
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To measure this part of antihydrogen's spectrum, they induced the anti-atoms to emit light by beaming a pulsed laser at them.
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But if heated materials in the form of plasma surround the black hole and emit light, the event horizon could be visible.
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This is because all four previous wave detections have come from the mergers of black holes, which are events that don't emit light.
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They're photosynthetic beings that hear and smell through their skin, emit light from their eyes when they feel strong emotions, and possess three hearts.
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This synchotron, the Diamond Light Source, accelerates electrons to nearly the speed of light, so that they emit light 10 billion times brighter than the sun.
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But to clear up some confusion, Samsung's QLED TVs still require backlighting and those crystals don't self-emit light in the same way that OLEDs do.
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Such differences can, in turn, be probed spectroscopically by using a laser to excite the electrons and measuring the wavelengths at which they then emit light.
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Other arguments from Hotz: Brake/traffic lights: LiDAR can't really detect brake lights, for example, which emit light at a different frequency than the LiDAR's lasers.
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When these organisms began colonizing deeper layers of the ocean, where the need for antioxidants is lower, coelenterazine's ability to emit light became useful, Rees theorized.
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Not only that, but other genetic tweaks make the neurons actually emit light when active, so the optrode can both influence and monitor the steering pathways.
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Clusters are thought to contain a lot of dark matter — a mysterious type of material that doesn't reflect or emit light but has a gravitational pull.
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Researchers have found another clue that might help explain the popularity of coelenterazine in deep-sea animals: the molecule also exists in organisms that don't emit light.
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WIMPs are a class of hypothetical elementary particles that hardly ever interact with regular baryonic matter and don't emit light, which makes them exceedingly hard to detect.
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Japanese researchers have developed touchable holograms, called Fairy Lights, which are made using a type of laser that can excite physical matter to emit light in 3D form.
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The lasers will emit light onto the lens displays, which will transform into images and video that will be projected into the user's eyes, according to the filing.
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Researchers are also experimenting with camouflaged wetsuits that seem to delay nibbles by a few minutes, and "counter-illumination" surfboards whose undersides emit light to diminish their silhouette.
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The big difference between two is that LED pixels needs a backlight that creates color through color filters, while OLED pixels emit light and independent colors on their own.
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Here's how that neutron star formed: For most of their existence, stars emit light through fusion — the merging of hydrogen atoms into helium, which releases gargantuan amounts of energy.
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Aside from the remarkable nature of the discovery itself, it also revived an old theory of dark matter based on massive astrophysical compact halo objects (MACHOs), ultradense objects that don't emit light.
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These large-scale structures guide the evolution of galaxies, but their exact mechanics are currently unknown and hard to observe because dark matter, annoyingly, does not emit light like stars or galaxies.
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To boost REM, Asprey says he creates a dark environment in which to sleep — he unplugs or covers all electrical devices that emit light and uses blackout curtains, which anyone can do.
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Dark matter is enigmatic material that does not emit light or energy and is thought to comprise about a quarter of the universe's combined mass and energy, but has not been directly observed.
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In recent years, scientists have figured out how to turn individual cells into functioning lasers, injecting fatty cells in pig skin with fluorescent dye and zapping them with lasers to get them to emit light.
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Here electrons are accelerated to near light speeds until they emit light 10 billion times brighter than the sun, then directed into laboratories in 'beamlines' which allow scientists to study minute specimens in extreme detail.
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That fishing pole-like thing you see over its head is called the esca, and it's nifty: Bacteria that emit light hang out in the esca, which is great when you're swimming in the deep, dark ocean.
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For comparison, the biggest telescope on the drawing board today has 798 separate mirror elements —and the challenges for telescopes focusing light from elsewhere are much less extreme than those facing arrays that emit light by the gigawatt.
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Details: 3 of ICON's 4 instruments are designed to study airglow — bands of faint light created when neutral particles in the atmosphere are slammed by radiation from the sun, exciting the particles and causing them to emit light.
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The patent says, "Exemplary methods and systems use a micro light emitting diode (LED) in an active matrix display to emit light and a sensing IR diode to sense light," with the sensing IR diode detecting and reading fingerprints.
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"This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 percent of everything and don't emit light, such as dark energy, dark matter, and dark radiation," Riess explained in a statement.
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The student reported that the treated cells indeed glowed green, but that the only phenomenon at work was auto-fluorescence: cells' tendency to emit light as they are dying, a possibility that Vacanti's researchers seemed oddly not to have entertained.
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Read More: Programmable Bioweapons Could Be the Nuclear Bombs of Future Wars "Chemical samples absorb and emit [light] at characteristic wavelengths that may be detected using laboratory, ground-based and airborne [...] sensors in the laboratory or field," the request for proposal states.
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Here electrons are accelerated to near light speeds until they emit light 10 billion times brighter than the sun, then directed into laboratories in 'beamlines' which allow scientists to study minute specimens using x-ray beams in extreme detail without damaging them.
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WASHINGTON (Reuters) - Astronomers have detected for the first time a galaxy that is devoid of dark matter, the plentiful but enigmatic material that does not emit light or energy and had been considered a fundamental part of all galaxies including our own Milky Way.
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After hundreds of years of relying only on electromagnetic radiation (such as light seen through a telescope), scientists can now use gravitational waves to directly observe a black hole (otherwise an impossibility, as it does not emit light in any form) or, as Bartusiak marvels, "to peer into the very heart of an exploding star" (gravitational waves, unlike electromagnetic radiation, are not dispersed or absorbed by matter as they pass through the universe).
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Emission nebulae emit light at specific wavelengths depending on their chemical composition.
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They also have organs on the head which produce red light; they are the only terrestrial organisms to emit light of this color.
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After the end of the excitation, the stored energy is gradually released to emitter centers which emit light usually by a fluorescence-like mechanism.
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Upon absorption of light, fluorescent materials emit light upon of a longer wavelength (lower energy) than the absorbed radiation, but cease to do so once immediately, when the illumination is stopped. The tagging of stamps uses substances that absorb ultraviolet light of wavelengths between 300 nm and 450 nm ("Black light", UVA, long-wave UV) and emit light in the visible spectrum. Under UV illumination they usually glow a greenish or yellowish colour. It must not be confused with the "whitening" of paper which is achieved by adding optical brighteners that usually re-emit light in the blue region of the spectrum, making the paper appear whiter by compensating a perceived deficit in reflected colours of these wavelengths.
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Bioluminescence is a chemical process that involves enzymes breaking down a substrate to produce light. Fluorescence is the physical excitation of an electron, and subsequent return to emit light.
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Coelenteramine is a metabolic product of the bioluminescent reactions in organisms that utilize coelenterazine. It was first isolated from Aequorea victoria along with coelenteramide after coelenterates were stimulated to emit light.
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Fluorescent materials absorb short-wavelength light and re-emit light at longer wavelengths. Due to the many scatterings this effect is much more pronounced in an integrating sphere than for materials irradiated normally.
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Single photon sources are novel types of light sources distinct from coherent light sources (lasers) and thermal light sources (such as incandescent light bulbs and mercury-vapor lamps) that emit light as single particles or photons.
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Point sources emit light from a single point in all directions, with the intensity of the light decreasing with distance. An example of a point source is a standalone light bulb. A directional light source illuminating a terrain.
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Figure 2 shows sagittal section of bobtail squid Euprymna scolopes. light organ. The crypts house symbiont bacteria Vibrio fischeri. They emit light during night time to camouflage themselves against the moon and star light coming down the ocean.
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Argon-ion lasers emit light in the range 351–528.7 nm. Depending on the optics and the laser tube a different number of lines is usable but the most commonly used lines are 458 nm, 488 nm and 514.5 nm.
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A naked singularity could allow scientists to observe an infinitely dense material, which would under normal circumstances be impossible by the cosmic censorship hypothesis. Without an event horizon of any kind, some speculate that naked singularities could actually emit light.
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A perfectly immobile fluorescent moiety when exited with polarized light will emit light which is also polarized. However, if a molecule is moving, it will tend to "scramble" the polarization of the light by radiating at a different direction from the incident light.
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Phosphor thermometry is an optical method for surface temperature measurement. The method exploits luminescence emitted by phosphor material. Phosphors are fine white or pastel-colored inorganic powders which may be stimulated by any of a variety of means to luminesce, i.e. emit light.
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"Does my current description imply a use?" If yes, create a more generic description involving its shape and material. For example, initially I divide a candle into its parts: wick and wax. The word "wick" implies a use: burning to emit light.
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The excited species will after some time, usually in the order of few nanoseconds to microseconds, de- excite and emit light at a wavelength longer than the excitation wavelength. This fluorescent light is typically recorded with a photomultiplier tube (PMT) or filtered photodiodes.
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Grow lamps contain phosphor blends that encourage photosynthesis, growth, or flowering in plants, algae, photosynthetic bacteria, and other light-dependent organisms. These often emit light primarily in the red and blue color range, which is absorbed by chlorophyll and used for photosynthesis in plants.
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A mechanical device with 3D printed snapper claw at five times the actual size was also reported to emit light in a similar fashion, this bioinspired design was based on the snapping shrimp snapper claw molt shed from an Alpheus formosus, the striped snapping shrimp.
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Bouncy balls may, by means of fluorescence, chemiluminescence, or motion- activated LEDs, emit light; such balls are called glow balls. Balls composed of many rubber bands, or bouncy balls made of borax, glue, and cornstarch, are sometimes homemade. Bouncy balls are often used in juggling.
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The bioluminescence can be turned on and off at will and may confuse potential predators. Other species of fish emit light in a similar way, and the particular arrangement of photophores in the scaly dragonfish permits individuals to identify other fish of the same species.
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Phosphorescent materials release the absorbed energy only slowly, so that they exhibit an "afterglow". Materials for stamp tagging absorb ultraviolet light of wavelengths between 180 nm and 300 nm (UVC, short-wave UV) and emit light of a greenish or reddish colour depending on the substances used.
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The family also includes Quantula striata, the only known terrestrial gastropod to emit light.. The Digestive system characteristics are as follows. The buccal mass is small. The jaw is smooth. The stomach is very simple with weak muscles (as is the case in the majority of land snails).
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The space-combat sim Tachyon: The Fringe utilizes "tachyon gates" for superluminal travel but gives no exact explanation for the technology, and the MMORPG Eve Online features six types of "Large Tachyon Lasers", technically a contradiction since by definition, lasers emit light-- photons, not any kind of hypothetical tachyon.
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Bell Rock Lighthouse, off the coast of Angus, Scotland Lists of lighthouses in the United Kingdom cover lighthouses, structures that emit light to serve as navigational aids, in the United Kingdom. They are organized by region. The list for Ireland includes both Northern Ireland and the Republic of Ireland.
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This provides counter-illumination camouflage, preventing the animal from appearing as a dark shape when seen from below. Some anglerfish of the deep sea, where it is too dark to hunt by sight, contain symbiotic bacteria in the 'bait' on their 'fishing rods'. These emit light to attract prey.Piper, Ross.
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The internal organs and viscera do not emit light. Luminescence is generated by a biochemical process in the millipede's exoskeleton. The light originates by way of a photoprotein, which differs from the photogenic molecule luciferase in firefly beetles. Motyxia's photoprotein contains a porphyrin and is about 104 kDa in size.
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Compounds eluting off the column are carried into a hydrogen fueled flame which excites specific elements in the molecules, and the excited elements (P,S, Halogens, Some Metals) emit light of specific characteristic wavelengths.Higson, S. (2004). Analytical Chemistry. OXFORD University Press The emitted light is filtered and detected by a photomultiplier tube.
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A plasma display panel (PDP) is a type of flat panel display common to large TV displays (37in. [940 mm]). Many tiny cells between two panels of glass hold an inert mixture of noble gases. The gas in the cells is electrically turned into a plasma which then excites phosphors to emit light.
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A low- pass filter blocks radiation above the frequency of the fluorescent light. In an active ALF, optical or electrical pumping is used for exciting these atoms so they absorb or emit light of different wavelengths. For active ALFs, other systems of conventional filters may be needed. Polarization of light by a Faraday filter.
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By selection of different semiconductor materials, single-color LEDs can be made that emit light in a narrow band of wavelengths from near-infrared through the visible spectrum and into the ultraviolet range. As the wavelengths become shorter, because of the larger band gap of these semiconductors, the operating voltage of the LED increases.
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Reflective twisted nematic liquid crystal display. A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly,Lawrence Ulrich: BOSCHs smart visual visor tracks sun. IEEE Spectrum, 29 January 2020.
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When certain compounds are illuminated with high energy light, they emit light of a lower frequency. This effect is known as fluorescence. Often specimens show their characteristic autofluorescence image, based on their chemical makeup. This method is of critical importance in the modern life sciences, as it can be extremely sensitive, allowing the detection of single molecules.
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Devices called "nanorods" are a form of LEDs that can also detect and absorb light. They consist of a quantum dot directly contacting two semiconductor materials (instead of just one as in a traditional LED). One semiconductor allows movement of positive charge and one allows movement of negative charge. They can emit light, sense light, and collect energy.
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Coelenteramide is the oxidized product, or oxyluciferin, of the bioluminescent reactions in many marine organisms that use coelenterazine. It was first isolated as a blue fluorescent protein from Aequorea victoria after the animals were stimulated to emit light. Under basic conditions, the compound will break down further into coelenteramine and 4-hydroxyphenylacetic acid. It is an aminopyrazine.
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Physics World (Jul 7, 2011) For absolute concealment, the events must be non-radiating. If they do emit light during their occurrence (e.g. by fluorescence), then this light is received by the distant observer as a single flash. Applications of the Event Cloak include the possibility to achieve `interrupt-without-interrupt' in data channels that converge at a node.
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When both electrons and holes are injected from opposite contacts, they can recombine radiatively and emit light (electroluminescence). It was observed in organic crystals in 1965 by Sano et al. In 1972, researchers found metallic conductivity in the charge-transfer complex TTF-TCNQ. Superconductivity in charge-transfer complexes was first reported in the Bechgaard salt (TMTSF)2PF6 in 1980.
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Some deep-sea anglerfishes of the bathypelagic zone emit light from their escas to attract prey. This bioluminescence is a result of symbiosis with bacteria. Several turtle species and the frogmouth catfish have tongue extensions that lure prey to a position where they become an easy catch. In caudal luring, the predator uses tail movements to attract prey.
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Light is perceived by the human visual system as white when the incoming light to the eye stimulates all three types of color sensitive cone cells in the eye in roughly equal amounts. Materials that do not emit light themselves appear white if their surfaces reflect back most of the light that strikes them in a diffuse way.
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In LCDs, there is an even layer of liquid crystal throughout the panel whereas an OLED display has the electroluminescent material only where it is meant to light up. OLEDs, LCDs and microLEDs can be made flexible and transparent, but LCDs require a backlight because they cannot emit light on their own like OLEDs and microLEDs.
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Most colonies are long, thin, transparent floaters living in the pelagic zone. Like other hydrozoans, some siphonophores emit light to attract and attack prey. While many sea animals produce blue and green bioluminescence, a siphonophore was only the second life form found to produce a red light (the first one being the scaleless dragonfish Chirostomias pliopterus).
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Photoexcitation is the production of an excited state of a quantum system by photon absorption. The excited state origins from the interaction between a photon and the quantum system. Photons carry energy that is determined by the wavelengths of the light that carries the photons. Objects that emit light with longer wavelengths, emit photons carrying less energy.
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In 1900, Max Planck developed a new theory of black- body radiation that explained the observed spectrum. Planck's theory was based on the idea that black bodies emit light (and other electromagnetic radiation) only as discrete bundles or packets of energy. These packets were called quanta. In 1905, Albert Einstein proposed that light quanta be regarded as real particles.
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An HPS (High Pressure Sodium) grow light bulb in an air-cooled reflector with hammer finish. The yellowish light is the signature color produced by an HPS. High- pressure sodium lights are a more efficient type of HID lighting than metal halides. HPS bulbs emit light in the yellow/red visible light as well as small portions of all other visible light.
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Zanna madagascariensis, the Malagasy lantern bug, is endemic to Madagascar. It is a member of the Zanninae, considered to be a subfamily of the Fulgoridae. The nymphs are sometimes referred to as lantern-flies because of their large lantern like snout, although this does not emit light. The adult bugs are known as sakandry, and are consumed by the rural people of Madagascar.
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These compounds dissociate near the hot center of the lamp, releasing isolated dysprosium atoms. The latter re-emit light in the green and red part of the spectrum, thereby effectively producing bright light. Several paramagnetic crystal salts of dysprosium (dysprosium gallium garnet, DGG; dysprosium aluminum garnet, DAG; dysprosium iron garnet, DyIG) are used in adiabatic demagnetization refrigerators.Milward, Steve et al. (2004).
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US and Canadian regulations require large vehicles to be equipped with amber side marker lights and reflectors mounted midway between the front and rear side markers. Australian Design Rule 45/01 provides for side marker lights on trucks and other large vehicles producing amber light to the front and red to the rear with no requirement to emit light to the side.
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The other built-in hubs are Xbox Music and Video, Xbox Live Games, Windows Phone Store, and Microsoft Office. Windows Phone uses multi-touch technology. The default Windows Phone user interface has a dark theme that prolongs battery life on OLED screens as fully black pixels do not emit light. Alternatively, users may choose a light theme in their phone's settings menu.
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On October 25, 2012, Owl City uploaded the official music video for "Shooting Star" to his official YouTube channel. The video's setting is nighttime in an urban area. The video features scenes of Young playing an electric piano under the street lights and people (who emit light from their chests) running, slowly gathering to all run together in the same direction.
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Compact and versatile options with UV-C LEDs Recent developments in LED technology have led to commercially available UV-C LEDs. UV-C LEDs use semiconductors to emit light between 255 nm and 280 nm. The wavelength emission is tuneable by adjusting the material of the semiconductor. , the electrical-to-UV-C conversion efficiency of LEDs was lower than that of mercury lamps.
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A Tesla coil will pass high-frequency current through the tube, and since it has a high voltage as well, the gases within the tube will ionize and emit light. This also works with plasma globes. Capacitive coupling with high-voltage power lines can light a lamp continuously at low intensity, depending on the intensity of the electric field, as shown in the image on the right.
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The goal of WALTA is to set up detectors at least 32 sites in the Seattle area, covering an area of 200 square kilometers. This area would be large enough to detect events above the GZK cutoff. The program hopes to fill in gaps in this area as the project matures. Each location has four scintillation detectors which emit light when hit by charged particles.
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A challenge in optical detection is the need for integrating detectors and photodiodes in a miniaturized portable format on the bio-MEMS. Optical detection includes fluorescence-based techniques, chemiluminescence-based techniques, and surface plasmon resonance (SPR). Fluorescence-based optical techniques use markers that emit light at specific wavelengths and the presence or enhancement/reduction (e.g. fluorescence resonance energy transfer) in optical signal indicates a reaction has occurred.
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For his cosmic ray research, Reynolds attempted to grow large organic crystal scintillators to use as ionized particle detectors. Scintillators are luminescent materials that, when struck by an incoming particle, absorb its energy and scintillate – emit light. They are used in many areas of scientific research. He was frustrated by cracks in the crystals, and attempted to get around the problem by dissolving them in liquid.
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Rubin Braunstein (1922–2018) was an American physicist and educator. In 1955 he published the first measurements of light emission by semiconductor diodes made from crystals of gallium arsenide (GaAs), gallium antimonide (GaSb), and indium phosphide (InP). GaAs, GaSb, and InP are examples of III-V semiconductors. The III-V semiconductors absorb and emit light much more strongly than silicon, which is the best-known semiconductor.
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The lighthouse at the initial stage is used to emit light once in 7 minutes. Fort Aguada was the most prized and crucial fort of Portuguese. The fort is so large that it envelops the entire peninsula at the southwestern tip of Bardez. Built on the mouth of Mandovi River, it was strategically located and was the chief defense of Portuguese against the Dutch and Marathas.
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The resulting ionization and excitation of atmospheric constituents emit light of varying color and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles. Precipitating protons generally produce optical emissions as incident hydrogen atoms after gaining electrons from the atmosphere. Proton auroras are usually observed at lower latitudes.
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A helium–neon laser emits light at 632 nanometers (red), while a frequency doubled Nd:YAG laser emits light at 532 nm (green). Various laser diodes and diode-pumped solid- state lasers emit light in red, yellow, green, blue or violet. Dye lasers can be tuned to emit nearly any color. However, lasers also experience a phenomenon called laser speckle, which shows up in the fringes.
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The difference is that the optical energy is not directly generated by the Sun, but instead by a material at high temperature (termed the emitter), that causes it to emit light. In this way thermal energy is converted to electrical energy. The emitter can be heated by sunlight or other techniques. In this sense, TPVs provide a great deal of versatility in potential fuels.
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A liquid crystal display (LCD) is a flat panel display, electronic visual display, video display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly. They are used in a wide range of applications, including computer monitors, television, instrument panels, laptops tablet computers etc. They are common in consumer devices such as video players, gaming devices, clocks, watches, calculators, and telephones.
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The beams can be bent by applying voltages to various electrodes in the tube or by holding a magnet close by. The electron beams are visible as fine bluish lines. This is accomplished by filling the tube with low pressure helium (He) or Hydrogen (H2) gas. A few of the electrons in the beam collide with the helium atoms, causing them to fluoresce and emit light.
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Distasteful animals use warning coloration (aposematism) to prevent attacks from potential predators. Many animals wish to advertise to those of their own species while being camouflaged to avoid predation. Many deep sea fish do this by way of bioluminescence. Patterns of photophores on their undersides emit light that from below hide their silhouettes and resemble the scintillating lights produced by the ever-moving surface layers of water.
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Aposematism is a widely used function of bioluminescence, providing a warning that the creature concerned is unpalatable. It is suggested that many firefly larvae glow to repel predators; some millipedes glow for the same purpose. Some marine organisms are believed to emit light for a similar reason. These include scale worms, jellyfish and brittle stars but further research is needed to fully establish the function of the luminescence.
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In Germany, scotophor tubes were developed by Telefunken as blauschrift-röhre ("dark-trace tube"). The heating mechanism was a layer of mica with transparent thin film of tungsten. When the image was to be erased, current was applied to the tungsten layer; even very dark images could be erased in 5–10 seconds. Scotophors typically require a higher- intensity electron beam to change color than phosphors need to emit light.
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In a light emitting diode, the recombination of electrons and electron holes in a semiconductor produces light (be it infrared, visible or UV), a process called "electroluminescence". The wavelength of the light depends on the energy band gap of the semiconductors used. Since these materials have a high index of refraction, design features of the devices such as special optical coatings and die shape are required to efficiently emit light.
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Modern biological microscopy depends heavily on the development of fluorescent probes for specific structures within a cell. In contrast to normal transilluminated light microscopy, in fluorescence microscopy the sample is illuminated through the objective lens with a narrow set of wavelengths of light. This light interacts with fluorophores in the sample which then emit light of a longer wavelength. It is this emitted light which makes up the image.
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Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers and lidar. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light.
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InP based lasers and LEDs can emit light in the very broad range of 1200 nm up to 12 µm. This light is used for fibre based Telecom and Datacom applications in all areas of the digitalised world. Light is also used for sensing applications. On one hand there are spectroscopic applications, where a certain wavelength is needed to interact with matter to detect highly diluted gases for example.
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Fluorescence spectroscopy aka fluorometry or spectrofluorometry, is a type of electromagnetic spectroscopy which analyzes fluorescence from a sample. It involves using a beam of light, usually ultraviolet light, that excites the electrons in molecules of certain compounds and causes them to emit light of a lower energy, typically, but not necessarily, visible light. A complementary technique is absorption spectroscopy. Devices that measure fluorescence are called fluorometers or fluorimeters.
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Nanoparticles along with multi-modal imaging techniques have been used as a way to diagnose cancer non-invasively. Skin with high permeability allowed quantum dots with an antibody attached to the surface for active targeting to successfully penetrate and identify cancerous tumours in mice. Tumour targeting is beneficial because the particles can be excited using fluorescence microscopy and emit light energy and heat that will destroy cancer cells.
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A hybrid silicon laser is an optical source that is fabricated from both silicon and group III-V semiconductor materials (e.g. Indium(III) phosphide, Gallium(III) arsenide). It comprises a silicon waveguide fused to an active, light-emitting, III-V epitaxial semiconductor wafer. The III-V epitaxial wafer is designed with different layers such that the active layer can emit light when it is excited either by shining light, e.g.
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If the beam struck the target, a "hit" was scored. Modern screen-based light guns work on the opposite principle—the sensor is built into the gun itself, and the on-screen target(s) emit light rather than the gun. The first light gun of this type was used on the MIT Whirlwind computer, which used a similar light pen. Like rail shooters, movement is typically limited in light-gun games.
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The other built-in hubs are Xbox Music and Video, Xbox Live Games, Windows Phone Store, and Microsoft Office. Due to Facebook Connect service changes, Facebook support is disabled in all bundled apps effective June 8, 2015. Windows Phone uses multi-touch technology. The default Windows Phone user interface has a dark theme that prolongs battery life on OLED screens as fully black pixels do not emit light.
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Larger dots emit longer wavelengths (red), while smaller dots emit shorter wavelengths (green). Blending together a mix of dot colors allows Nanosys to precisely engineer a new spectrum of light to customer specifications. The Quantum Dots are tuned to create better color by changing their size during fabrication to emit light at just the right wavelengths. Traditional light emitting materials such as crystal phosphors have a broad fixed spectrum.
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250x250px Fluorescence imaging is a type of non-invasive imaging technique that can help visualize biological processes taking place in a living organism. Images can be produced from a variety of methods including: microscopy, imaging probes, and spectroscopy. Fluorescence itself, is a form of luminescence that results from matter emitting light of a certain wavelength after absorbing electromagnetic radiation. Molecules that re-emit light upon absorption of light are called fluorophores.
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The excited analyte atoms emit light at characteristic wavelengths that can be dispersed with a monochromator and detected. In the past, the spark or arc conditions were typically not well controlled, the analysis for the elements in the sample were qualitative. However, modern spark sources with controlled discharges can be considered quantitative. Both qualitative and quantitative spark analysis are widely used for production quality control in foundry and metal casting facilities.
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Unlike photoproteins which stably bind coelenterazine and emit light upon addition of calcium, coelenterazine is normally bound by RrLBP, the luciferin-binding protein. When stimulated, a Ca2+ ion first interacts with RrLBP, causing it to release coelenterazine. Coelenterazine is then oxidized by RLuc into coelenteramide, releasing a single photon of blue light (480 nm) in the process. This photon is captured by the adjacent GFP, releasing a photon of green light.
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If the semiconductor is translucent, the junction becomes the source of light, thus becoming a light- emitting diode. I-V diagram for a diode. An LED begins to emit light when more than 2 or 3 volts is applied in the forward direction. The reverse bias region uses a different vertical scale from the forward bias region to show that the leakage current is nearly constant with voltage until breakdown occurs.
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The basic coloration is dark brown. The eyes are large and the pronotum is yellowish or pale brown, with a blackish area in the middle and small backward-pointing teeth. These beetles are bioluminescent by means of two luminescent light organs at the posterior corners of the prothorax, emitting green light, and a large abdominal area on the first segment, emitting yellow light. They do not flash, they emit light continuously.
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Carl Seyfert published many papers in the astronomical literature, on a wide variety of topics in stellar and galactic astronomy, as well as on observing methods and instrumentation. In 1943 he published a paper on galaxies with bright nuclei that emit light with emission line spectra with characteristically broadened emission lines. The prototype example is Messier 77 (NGC 1068). It is this class of galaxies that is now known as Seyfert galaxies, in his honor.
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At the time, Leigh Canham – while working at the Defence Research Agency in England – reasoned that the porous silicon may display quantum confinement effects.Sailor Research Group 17 February 2003, Introduction to Porous Si, Sailor research group at UCSD, Department of Chemistry, University of California. The intuition was followed by successful experimental results published in 1990. In the published experiment, it was revealed that silicon wafers can emit light if subjected to electrochemical and chemical dissolution.
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While Franck and Hertz were unaware of it when they published their experiments in 1914, in 1913 Niels Bohr had published a model for atoms that was very successful in accounting for the optical properties of atomic hydrogen. These were usually observed in gas discharges, which emitted light at a series of wavelengths. Ordinary light sources like incandescent light bulbs emit light at all wavelengths. Bohr had calculated the wavelengths emitted by hydrogen very accurately.
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Pyrops candelaria (Laternaria candelaria and Fulgora candelaria in older literature) is a species of planthopper that lives in Vietnam, Hong Kong, Laos, Thailand and other parts of southeast Asia. It is the type of the genus Pyrops erected by Spinola in 1839. Members of this genus are sometimes called lanternflies (although lanternflies do not emit light). Like all Fulgoridae, P. candelaria feeds on plant sap: including longan and lychee trees (Sapindaceae), among others.
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Xenon, operated as a 'neon light,' consists of a collection of mostly spectral lines, missing much of the continuum radiation needed for good color rendering. Spectral line radiation from a xenon flashlamp. Although invisible to the naked eye, the digital camera is able to image the strong IR spectral lines, which appear as the blue light reflected off the table. As with all ionized gases, xenon flashtubes emit light in various spectral lines.
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The cross-linking in polydioctylfluorene structure provides an efficient technique for hole-transport layers to emit light. Also, when a solvent-polymer compound is added the β-phase crystalline structure to be maintained. Efficiency in current can reach a maximum of about 17 cd/A and maximum luminance obtained can be approximately 14,000 cd/m(2). The hole-transport layers (HTLs) improve the polymer's anode hole injection and greatly increase electron blocking.
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Polymer light-emitting diodes (PLEDs), similar to SM-OLED, emit light under an applied electric current. Polymer-based OLEDs are generally more efficient than SM- OLEDs requiring a comparatively lower amount of energy to produce the same luminescence. Common polymers used in PLEDs include derivatives of poly(p-phenylene vinylene) and polyfluorene. The emitted color can be tuned by substitution of different side chains onto the polymer backbone or modifying the stability of the polymer.
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Hot metal work glows with visible light. This thermal radiation also extends into the infrared, invisible to the human eye and the camera the image was taken with, but an infrared camera could show it (See Thermography). spark used to light this Bunsen burner emit light ranging in color from white to orange to yellow to red or to blue. This change correlates with their temperature as they cool in the air.
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Time-correlated single-photon counting (TCSPC) precisely records the arrival times of individual photons, enabling measurement of picosecond time-scale differences in the arrival times of photons generated by fluorescent, phosphorescence or other chemical processes that emit light, providing additional molecular information about samples. The use of TCSPC enables relatively slow detectors to measure extremely minute time differences that would be obscured by overlapping impulse responses if multiple photons were incident concurrently.
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Its most distinguishing features are the cream-colored light organs underneath its eyes, which produce blue-green light likely used by the fish to attract prey, communicate with other fish, and frighten and confuse predators. These organs contain bioluminescent bacteria, fed by oxygen and nutrients from the fish's bloodstream, which emit a constant light. The eyelight fish uses a black lid to cover the organs when it does not want to emit light.
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Black-body radiation, the emission of electromagnetic energy due to an object's heat, could not be explained from classical arguments alone. The equipartition theorem of classical mechanics, the basis of all classical thermodynamic theories, stated that an object's energy is partitioned equally among the object's vibrational modes. But applying the same reasoning to the electromagnetic emission of such a thermal object was not so successful. That thermal objects emit light had been long known.
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When these caterpillars die, their luminosity may attract predators to the dead insect thus assisting in the dispersal of both bacteria and nematodes. A similar reason may account for the many species of fungi that emit light. Species in the genera Armillaria, Mycena, Omphalotus, Panellus, Pleurotus and others do this, emitting usually greenish light from the mycelium, cap and gills. This may attract night-flying insects and aid in spore dispersal, but other functions may also be involved.
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Fluorescence of Aragonite Gemstones, minerals, may have a distinctive fluorescence or may fluoresce differently under short-wave ultraviolet, long-wave ultraviolet, visible light, or X-rays. Many types of calcite and amber will fluoresce under shortwave UV, longwave UV and visible light. Rubies, emeralds, and diamonds exhibit red fluorescence under long-wave UV, blue and sometimes green light; diamonds also emit light under X-ray radiation. Fluorescence in minerals is caused by a wide range of activators.
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Stauroteuthis is one of only two genera of octopuses to exhibit bioluminescence. S. syrtensis emits a blue-green light from about 40 modified suckers known as photophores situated in a single row between the pairs of cirri on the underside of each arm. The distance between these decreases towards the ends of the arms with the light becoming fainter. The animal does not emit light continuously, but can do so for a period of five minutes after suitable stimulation.
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Watercolour of bioluminescent krill Krill are often referred to as light-shrimp because they emit light through bioluminescent organs. These organs are located on various parts of the individual krill's body: one pair of organs at the eyestalk (cf. the image of the head above), another pair are on the hips of the second and seventh thoracopods, and singular organs on the four pleonsternites. These light organs emit a yellow-green light periodically, for up to 2–3 s.
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The glowplug is a pencil-shaped piece of metal with a heating element at the tip. This heating element, when electrified, heats due to its electrical resistance and begins to emit light in the visible spectrum, hence the term glowplug. The visual effect is similar to the heating element in a toaster. The fuel injector spray pattern then impinges directly upon the hot tip of the glow plug during the injection of fuel at top dead center.
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Aveiro, on the west coast of Portugal. Aerial drone footage of the Roman Rock Lighthouse off the southern coast of South Africa. A lighthouse is a tower, building, or another type of structure designed to emit light from a system of lamps and lenses and to serve as a navigational aid for maritime pilots at sea or on inland waterways. Lighthouses mark dangerous coastlines, hazardous shoals, reefs, rocks, and safe entries to harbors; they also assist in aerial navigation.
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These superior properties are compelling reasons to use GaAs circuitry in mobile phones, satellite communications, microwave point-to-point links and higher frequency radar systems. It is also used in the manufacture of Gunn diodes for the generation of microwaves. Another advantage of GaAs is that it has a direct band gap, which means that it can be used to absorb and emit light efficiently. Silicon has an indirect band gap and so is relatively poor at emitting light.
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Phlebology, 255: 751- 3. The principles of spectrographic analysis of this test are similar to those used to evaluate the luminescence of captured images by venous translumination, and the histogram also evaluates the scales of red, blue and green (RGB). All organic components are composed of chemical elements that emit light according to their wavelength. This is why the histogram analysis of transluminated images could define an organic element according to the quality and amount of their components.
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In practice, two different beams originated in separate lasers are overlapped. While one of the beams is used for velocity measurements, the other is used to measure the temperature. The use of thermographic phosphors offers some advantageous features including ability to survive in reactive and high temperature environments, chemical stability and insensitivity of their phosphorescence emission to pressure and gas composition. In addition, thermographic phosphors emit light at different wavelengths, allowing spectral discrimination against excitation light and background.
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Jablonski diagram of FRET Fluorescence Resonance Energy Transfer (FRET) utilizes energy transferred between the donor and the acceptor molecules that are in close proximity. FRET uses a fluorescently labeled ligand, as with FP. Energy transfer within FRET begins by exciting the donor. The dipole-dipole interaction between the donor and the acceptor molecule transfers the energy from the donor to the acceptor molecule. If the ligand is bound to the receptor-antibody complex, then the acceptor will emit light.
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An Organic Light Emitting Diode (OLED), also Light Emitting Polymer (LEP) and Organic Electro Luminescence (OEL), is any Light Emitting Diode (LED) whose emissive electroluminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors.
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In most anglerfish species, the longest filament is the first. This first spine protrudes above the fish's eyes and terminates in an irregular growth of flesh (the esca), and can move in all directions. Anglerfish can wiggle the esca to make it resemble a prey animal, which lures the anglerfish's prey close enough for the anglerfish to devour them whole. Some deep-sea anglerfish of the bathypelagic zone also emit light from their esca to attract prey.
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In addition to its ability to emit light under a strain of greater than 480% its original size, the group's HLEC was shown to be capable of being integrated into a soft robotic system. Three six-layer HLEC panels were bound together to form a crawling soft robot, with the top four layers making up the light-up skin and the bottom two the pneumatic actuators. The discovery could lead to significant advances in health care, transportation, electronic communication and other areas.
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Flashing LEDs are used as attention seeking indicators without requiring external electronics. Flashing LEDs resemble standard LEDs but they contain an integrated voltage regulator and a multivibrator circuit that causes the LED to flash with a typical period of one second. In diffused lens LEDs, this circuit is visible as a small black dot. Most flashing LEDs emit light of one color, but more sophisticated devices can flash between multiple colors and even fade through a color sequence using RGB color mixing.
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Chemical reactions cause nitrogen and oxygen to be removed from the bubble after about one hundred expansion-collapse cycles. The bubble will then begin to emit light. The light emission of highly compressed noble gas is exploited technologically in the argon flash devices. During bubble collapse, the inertia of the surrounding water causes high pressure and high temperature, reaching around 10,000 kelvins in the interior of the bubble, causing the ionization of a small fraction of the noble gas present.
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Around the ring are 40 straight sections. One of these sections is used to inject electrons into the ring, and four are dedicated to replenishing the electron energy lost though x-ray emission by using 16 radio- frequency accelerating cavities. The remaining 35 straight sections can be equipped with insertion devices. Insertion devices, arrays of north-south permanent magnets usually called “undulators” or "wigglers", cause the electrons to oscillate and emit light in the invisible part of the electromagnetic spectrum.
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In 1595, the church was placed under the jurisdiction of the nearby Basilica of San Crisogono. In 1728, a Pope Benedict XIII assigned the church to the Minims, an order established by St. Francis of Paola. The current name of the church dates from 1730, when a series of miracles were linked to an icon painted on the exterior of a nearby house nearby, which was seen to emit light. The image was then transferred to the Church, and changed name.
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Different species of fireflies all use the same luciferin, however the color of the light emitted can differ greatly. The light from Photuris pennsylvanica was measured to be 552 nm (green-yellow) while Pyrophorus plagiophthalamus was measured to emit light at 582 nm (orange) in the ventral organ. Such differences are likely due to pH changes or differences in primary structure of the luciferase. Modification of the firefly luciferin substrate has led to "red-shifted" emissions (up to emission wavelength of 675 nm).
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This effect is termed the EPR paradox (although it is not a true paradox). The Local realism hypothesis on the other hand states that measurement on one photon has no influence whatsoever on the other. As a basis for our description of experimental errors consider a typical experiment of CHSH type (see picture to the right). In the experiment the source is assumed to emit light in the form of pairs of particle-like photons with each photon sent off in opposite directions.
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Photobacterium is a genus of gram-negative bacteria in the family Vibrionaceae. Members of the genus are bioluminescent, that is they have the ability to emit light. Many species, including Photobacterium leiognathi and Photobacterium phosphoreum, live in symbiosis with marine organisms. Species such as Photobacterium profundum are adapted for optimal growth in the deep cold seas making it both a psychrophile (an organism capable of growth and reproduction in cold temperatures) and a piezophile (an organism which thrives at high pressures).
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Spawning has been documented in the early months of April and May, though it is likely the fish spawns at other times during the year as well. The symbiotic bacteria in its light organs differ substantially from the bacteria found in other anomalopids. Some bacteria are released from its light organs and remain viable after being discharged, but cease to emit light shortly thereafter. To shut off the light, the eyelight fish uses black lids that slide up to cover the light organs.
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Scientists had observed that light traveling through a medium would be absorbed at different wavelengths, depending on the matter-composition of the medium involved. A white light source would emit light at multiple wavelengths over a range of frequencies. A prism could be used to separate a light source into specific wavelengths. Shining the light through a sample of a material would cause some wavelengths of light to be absorbed, while others would be unaffected and continue to be transmitted.
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He once told an opponent that he could see his nerve centers and on another occasion said he can hear a heartbeat of a butterfly in Africa while he's in the US. He can emit light, which can be used for a pacifying effect. He possesses an ability to absorb energy from any matter/source which provides him limitless energy. Sentry possesses tremendous powers of energy projection, from both his hands and eyes,Dark Reign: Young Avengers #5. Marvel Comics.
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In more detail, when the radio-labelled molecule is attached or is in proximity to bead, light emission is stimulated. However, if the bead does not become bound to the radio-labelled molecule, the bead will not be stimulated to emit light. This is because the energy released from the unbound molecule is not strong enough to excite the SPA bead which is not then stimulated to produce a signal. The decay of radioactive atom releases electrons as one of the subatomic particles.
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There is no cure for this disorder; however, symptoms can usually be managed by limiting exposure to daytime sun and some types of artificial lighting. Most types of artificial lighting emit light in the problematic wavelengths, with fluorescent lighting being the worst offender. Color temperature can be a good indicator of what light is most detrimental, as the higher the color temperature, the more violet light (380-450 nm) is emitted. Incandescent and LED lighting in the soft white range (2700-3000K) produce the least problematic light.
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SEM image of an InGaN polycrystal. The blue and green channels represent real colors, the red channel corresponds to UV emission. SEM, real colors In these instruments a focused beam of electrons impinges on a sample and induces it to emit light that is collected by an optical system, such as an elliptical mirror. From there, a fiber optic will transfer the light out of the microscope where it is separated into its component wavelengths by a monochromator and is then detected with a photomultiplier tube.
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Thus a relatively low temperature emits a dull red and a high temperature emits the almost white of the traditional incandescent light bulb. Metal workers are able to judge the temperature of hot metals by their color, from dark red to orange-white and then white (see red heat). Many other light sources, such as fluorescent lamps, or light emitting diodes (LEDs) emit light primarily by processes other than thermal radiation. This means that the emitted radiation does not follow the form of a black-body spectrum.
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The test involves introducing a sample of the element or compound to a hot, non-luminous flame, and observing the color of the flame that results. The idea of the test is that sample atoms evaporate and since they are hot, they emit light when being in flame. Bulk sample emits light too, but its light is not good for analysis. Bulk sample emits light primarily due to the motion of the electrons, therefore its spectrum is broad, consisting of a broad range of colors.
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Separate atoms of a sample present in the flame can emit only due to electronic transitions between different atomic energy levels. Those transitions emit light of very specific frequencies, characteristic of the chemical element itself. Therefore, the flame gets the color, which is primarily determined by properties of the atomic energy shells of the chemical element of the substance being put into flame. The flame test is a relatively easy experiment to set up and thus is often demonstrated or carried out in science classes in schools.
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A fluorophore-labeled human cell. A fluorophore (or fluorochrome, similarly to a chromophore) is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with several π bonds. Fluorophores are sometimes used alone, as a tracer in fluids, as a dye for staining of certain structures, as a substrate of enzymes, or as a probe or indicator (when its fluorescence is affected by environmental aspects such as polarity or ions).
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Many e-readers, devices meant to replace traditional books, utilize electronic paper for their displays in order to further resemble paper books; one such example is the Kindle series by Amazon. Electronic paper, also sometimes electronic ink or electrophoretic display, are display devices that mimic the appearance of ordinary ink on paper. Unlike conventional flat panel displays that emit light, electronic paper displays reflect light like paper. This may make them more comfortable to read, and provide a wider viewing angle than most light-emitting displays.
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Cells containing successfully ligated insert can then be easily identified by its white coloration from the unsuccessful blue ones. Other commonly used reporter genes are green fluorescent protein (GFP), which produces cells that glow green under blue light, and the enzyme luciferase, which catalyzes a reaction with luciferin to emit light. The recombinant DNA may also be detected using other methods such as nucleic acid hybridization with radioactive RNA probe, while cells that expressed the desired protein from the plasmid may also be detected using immunological methods.
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Typical core-domain of an FbFP () A FMN-binding fluorescent protein (FbFP), also known as a LOV-based fluorescent protein, is a small, oxygen-independent fluorescent protein that binds flavin mononucleotide (FMN) as a chromophore. They were developed from blue-light receptors (so called LOV-domains) found in plants and various bacteria. They complement the GFP-derivatives and –homologues and are particularly characterized by their independence of molecular oxygen and their small size. FbFPs absorb blue light and emit light in the cyan-green spectral range.
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150px Like all types of OLED, phosphorescent OLEDs emit light due to the electroluminescence of an organic semiconductor layer in an electric current. Electrons and holes are injected into the organic layer at the electrodes and form excitons, a bound state of the electron and hole. Electrons and holes are both fermions with half integer spin. An exciton is formed by the coulombic attraction between the electron and the hole, and it may either be in a singlet state or a triplet state, depending on the spin states of these two bound species.
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It has an inbuilt biological clock and, even when kept in total darkness, turns its light on and off in a circadian rhythm. Fireflies use light to attract mates. Two systems are involved according to species; in one, females emit light from their abdomens to attract males; in the other, flying males emit signals to which the sometimes sedentary females respond. Click beetles emit an orange light from the abdomen when flying and a green light from the thorax when they are disturbed or moving about on the ground.
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Semiconductor nanoparticles or quantum dots have often been demonstrated to emit light of shorter wavelength than the excitation following a two-photon absorption mechanism, not photon upconversion. However, recently the use of semiconductor nanoparticles, such as CdSe, PbS and PbSe as sensitizers combined with molecular emitters has been shown as a new strategy for photon upconversion through triplet-triplet annihilation. They have been used to upconvert 980 nm infrared light to 600 nm visible light; green light to blue light; and blue light to ultraviolet. This technique benefits from a very high upconverting capability.
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Some high-intensity discharge (HID) lamps couple their even-greater electrical efficiency with phosphor enhancement for better color rendition. White light-emitting diodes (LEDs) became available in the mid-1990s as LED lamps, in which blue light emitted from the semiconductor strikes phosphors deposited on the tiny chip. The combination of the blue light that continues through the phosphor and the green to red fluorescence from the phosphors produces a net emission of white light. Glow sticks sometimes utilize fluorescent materials to absorb light from the chemiluminescent reaction and emit light of a different color.
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Although direct bandgap semiconductors such as GaAs or GaN are most easily examined by these techniques, indirect semiconductors such as silicon also emit weak cathodoluminescence, and can be examined as well. In particular, the luminescence of dislocated silicon is different from intrinsic silicon, and can be used to map defects in integrated circuits. Recently, cathodoluminescence performed in electron microscopes is also being used to study surface plasmon resonances in metallic nanoparticles. Surface plasmons in metal nanoparticles can absorb and emit light, though the process is different from that in semiconductors.
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Diamonds exhibit fluorescence, that is, they emit light of various colors and intensities under long-wave ultraviolet light (365 nm): Cape series stones (type Ia) usually fluoresce blue, and these stones may also phosphoresce yellow, a unique property among gemstones. Other possible long-wave fluorescence colors are green (usually in brown stones), yellow, mauve, or red (in type IIb diamonds). In natural diamonds, there is typically little if any response to short-wave ultraviolet, but the reverse is true of synthetic diamonds. Some natural type IIb diamonds phosphoresce blue after exposure to short-wave ultraviolet.
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A pickle glowing when an electric current is passed through it Applying line voltage across a pickled cucumber causes it to glow. A moist pickle contains salt as a result of the pickling process, which allows it to conduct electricity. Sodium (or other) ions within the pickle emit light as a result of atomic electron transitions, although it is not clear why the luminescence occurs at one end of the pickle. The glowing pickle is used to demonstrate ionic conduction and atomic emission in chemistry classes, and also as a demonstration in lighting classes.
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The skylights are designed to emit light on its exterior side, glowing "like a lantern". A curved designed is used throughout the interior, as a reflection of Northern Canada's "openness". The Inuit Art Centre's atrium features a serpentine steel frame of the building's three-storey visible storage for works for items in the Inuit collection not on exhibit. The visible storage is adjacent to the building's entrance on the corner of St. Mary's Avenue and Memorial Boulevard, with a lecture room, café, and reading room adjacent to the building's atrium.
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De Phenomenis in Orbe Lunae is a 1612 book by Collegio Romano philosophy professor Giulio Cesare la Galla that describes emission of light by a stone. La Galla's inspiration came from Galileo's debate with Vincenzo Casciarolo regarding a "lapis solaris," a stone that emitted light seemingly on its own. In De Phenomenis, de Galla asserts that the stone was only able to emit light after the stone itself had calcified. It released "a certain quantity of fire and light" that it had absorbed, just as water would be absorbed by a sponge.
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Tait's experiments were inspired by a paper of Helmholtz's on vortex-rings in incompressible fluids. Thomson and Tait believed that an understanding and classification of all possible knots would explain why atoms absorb and emit light at only the discrete wavelengths that they do. For example, Thomson thought that sodium could be the Hopf link due to its two lines of spectra.Alexei Sossinsky (2002) Knots, Mathematics with a Twist, Harvard University Press Tait subsequently began listing unique knots in the belief that he was creating a table of elements.
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The church's Mission Revival–Spanish Colonial Revival structure supports four domes spanning the length of the Basilica. All the domes are compound design with the pendentives, following Roman architecture, transferring the weight of the roof to the pillars. The dome over the intercept point of the crossover, the nave center aisle and the apse, is topped with stained glass and features a lantern above the dome to emit light into the nave and sanctuary. The dome located over the altar is topped with a cupola designed to provide light to the altar.
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Luminescent bacteria emit light as the result of a chemical reaction during which chemical energy is converted to light energy. Luminescent bacteria exist as symbiotic organisms carried within a larger organism, such as many deep sea organisms, including the Lantern Fish, the Angler fish, certain jellyfish, certain clams and the Gulper eel. The light is generated by an enzyme- catalyzed chemoluminescence reaction, wherein the pigment luciferin is oxidised by the enzyme luciferase. The expression of genes related to bioluminescence is controlled by an operon called the lux operon.
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Common applications of BLI include in vivo studies of infection (with bioluminescent pathogens), cancer progression (using a bioluminescent cancer cell line), and reconstitution kinetics (using bioluminescent stem cells). Researchers at UT Southwestern Medical Center have shown that bioluminescence imaging can be used to determine the effectiveness of cancer drugs that choke off a tumor's blood supply. The technique requires luciferin to be added to the bloodstream, which carries it to cells throughout the body. When luciferin reaches cells that have been altered to carry the firefly gene, those cells emit light.
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However, if the excited fluorescent molecule is in motion (rotational or translational) during the fluorescent lifetime, it will emit light in a different direction than the excitation plane. The fluorescent lifetime is the amount of time between the absorption moment and the fluorescent emission moment. Typically, the rate at which a molecule rotates is indicative of its size. When a fluorescent-labelled molecule (tracer) binds to another molecule the rotational motion will change, resulting in an altered intensity of plane-polarized light, which results in altered fluorescence polarization.
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Hydrogen is easily detected in the ultraviolet (UV) and visible ranges from its absorption and emission of light (the hydrogen line). Moreover, most organic compounds absorb and emit light in the infrared (IR) so, for example, the detection of methane in the atmosphere of Mars was achieved using an IR ground-based telescope, NASA's 3-meter Infrared Telescope Facility atop Mauna Kea, Hawaii. NASA's researchers use airborne IR telescope SOFIA and space telescope Spitzer for their observations, researches and scientific operations. Somewhat related to the recent detection of methane in the atmosphere of Mars.
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This less common arrangement makes it easy to re-inject electrons from the valence band of one stage of the ICL into the conduction band of the next stage via simple elastic scattering. Each cascade stage effectively acts as an individual photon generator. A single stage is composed of an electron injector, a hole injector, and an active gain region consisting of one hole QW and one or two electron QWs. When the device is biased, excess electrons and holes are generated and flow into the active region, where they recombine and emit light.
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A quantum well laser is a laser diode in which the active region of the device is so narrow that quantum confinement occurs. Laser diodes are formed in compound semiconductor materials that (quite unlike silicon) are able to emit light efficiently. The wavelength of the light emitted by a quantum well laser is determined by the width of the active region rather than just the bandgap of the material from which it is constructed.Foreword, "The Origin of Quantum Wells and the Quantum Well Laser," by Charles H. Henry, in "Quantum Well Lasers," ed.
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The TDEL structure is made on a glass or other inexpensive substrate consisting of a thick-film dielectric layer and a thin-film phosphor layer squished between two sets of electrodes to make a matrix of pixels. It seems complex, but basically it works when phosphors emit light in the presence of an electric field. And because TDEL uses solid-state phosphors instead of liquids (as with LCDs), gases (as with PDP) or vacuum (as with the CRT), it is probably the most sturdy new technology, less prone to shock and breakage during shipping.
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Catherine Labouré, a French member of the Daughters of Charity of Saint Vincent de Paul, reported that in 1830, she experiences a vision of Mary in the convent chapel on the Rue du Bac, in Paris. Labouré said that Mary appeared standing upon on globe with her arms outstretched. As if from rings set with precious stones dazzling rays of light were emitted from her fingers. When asked why all the rings did not emit light, the apparition responded that these were graces for which people forget to ask.
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An adult M. sequoiae photographed in normal light (A) and its own light (B) The 9 species and 11 subspecies of Motyxia are some of the few known bioluminescent species of millipedes, a class of about 12,000 known species. Motyxia sequoiae glows the brightest and Motyxia pior the dimmest. Light is emitted from the exoskeleton of the millipede continuously, with peak wavelength of 495 nm (the light intensifies when the millipede is handled). Emission of light is uniform across the exoskeleton, and all the appendages (legs, antennae) and body rings emit light.
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This is due to a fast catalytic step, which produces the light, and a slow regeneration step, where the oxyluciferin is freed and another molecule of luciferin is then enabled to bind to the enzyme. Because of the kinetically slow step, each aequorin molecule must "recharge" with another molecule of luciferin before it can emit light again, and this makes it appear as though it is not behaving as a typical enzyme. Photoproteins form a stable luciferin- photoprotein complex, often until the addition of another required factor such as Ca2+ in the case of aequorin.
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The temperature of the envelope must be carefully controlled, since the behaviour of the arc is determined largely by the vapor pressure of the mercury, which in turn is set by the coolest spot on the enclosure wall. A typical design maintains temperature at and a mercury vapor pressure of 7 millipascals. The mercury ions emit light at characteristic wavelengths, the relative intensities of which are determined by the pressure of the vapor. At the low pressure within a rectifier, the light appears pale blue-violet and contains much ultraviolet light.
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In light-emitting diode physics, the recombination of electrons and electron holes in a semiconductor produce light (or infrared radiation), a process called "electroluminescence". The wavelength of the light produced depends on the energy band gap of the semiconductors used. Since these materials have a high index of refraction, design features of the devices such as special optical coatings and die shape are required to efficiently emit light. An LED is a long-lived light source, but certain mechanisms can cause slow loss of efficiency of the device or sudden failure.
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In addition to the binding of an antibody to its antigen, the other key feature of all immunoassays is a means to produce a measurable signal in response to the binding. Most, though not all, immunoassays involve chemically linking antibodies or antigens with some kind of detectable label. A large number of labels exist in modern immunoassays, and they allow for detection through different means. Many labels are detectable because they either emit radiation, produce a color change in a solution, fluoresce under light, or can be induced to emit light.
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Edison light bulbs, retroactively referred to as antique light bulbs, and vintage light bulbs, refer to carbon- or early tungsten-filament light bulbs, or modern bulbs reproducing their appearance. Most of these bulbs are reproductions of the wound filament bulbs made popular by Edison Electric Light Company at the turn of the 20th century. They are easily identified by the long and complicated windings of their internal filaments, and by the very warm-yellow glow of the light they produce (many of the bulbs emit light at a color temperature of 2200–2400K).
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For this reason, it was also called Seoul Lite before being officially named the Digital Media City Landmark Building. The outward appearance of the building is to be made in a style reminiscent of the windows of traditional Korean houses. Its design specifies the installation of an exterior super skin containing 40,000 LED panels that emit light of various colors. The bamboo-type structure of the building, with the heart section left empty, increases its resistance to bending three-fold, thus enhancing its structural stability against earthquakes and vibration due to wind.
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Scintillation proximity assay (SPA) is an assay development and biochemical screening that permits the rapid and sensitive measurement of a broad range of biological processes in a homogeneous system. The type of beads that are involved in the SPA are microscopic in size and within the beads itself, there is a scintillant which emits light when it is stimulated. Stimulation occurs when radio-labelled molecules interact and bind to the surface of the bead. This interaction will trigger the bead to emit light, which can be detected using a photometer.
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It is due to the 1.5 µm path length through water, which is very short. So, when the ß-particle is within that particular range of 1.5 µm with the scintillant bead, there is sufficient energy to stimulate the bead to emit light. If the distance between them is greater than 1.5 µm, then the ß-particle is incapable of travelling the required distance to stimulate the bead as it has insufficient energy. The beads in SPA are formed from the incorporation of scintillant into small beads known as fluomicrospheres.
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Since no real laser is truly monochromatic, all lasers can emit light over some range of frequencies, known as the linewidth of the laser transition. In most lasers, this linewidth is quite narrow (for example, the nm wavelength transition of a Nd:YAG laser has a linewidth of approximately 120 GHz, or 0.45 nmKoechner, §2.3.1, p49.). Tuning of the laser output across this range can be achieved by placing wavelength-selective optical elements (such as an etalon) into the laser's optical cavity, to provide selection of a particular longitudinal mode of the cavity.
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Antibiotic resistant bacteria Wiles leads the Bioluminescent Superbugs Lab at the University of Auckland which focuses on how glowing bacteria can advance the understanding of microbial infections such as food poisoning, tuberculosis and hospital superbugs. The bioluminescence is used to speed up the process of developing new antibiotics utilising the light emitted from the bacteria, because only living bacteria emit light. About her work Wiles says "My career has been built on making nasty bacteria bioluminescent and using them for all sorts of things, including finding new medicines". New Zealand has some of the highest rates of infectious diseases among developed countries.
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The specimen is illuminated with light of a specific wavelength (or wavelengths) which is absorbed by the fluorophores, causing them to emit light of longer wavelengths (i.e., of a different color than the absorbed light). The illumination light is separated from the much weaker emitted fluorescence through the use of a spectral emission filter. Typical components of a fluorescence microscope are a light source (xenon arc lamp or mercury-vapor lamp are common; more advanced forms are high-power LEDs and lasers), the excitation filter, the dichroic mirror (or dichroic beamsplitter), and the emission filter (see figure below).
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Planetary nebulae, represented here by the Ring Nebula, are examples of emission nebulae. An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths. The most common source of ionization is high-energy ultraviolet photons emitted from a nearby hot star. Among the several different types of emission nebulae are H II regions, in which star formation is taking place and young, massive stars are the source of the ionizing photons; and planetary nebulae, in which a dying star has thrown off its outer layers, with the exposed hot core then ionizing them.
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Perdaix will make use of a scintillating fiber tracking detector made up from 250 µm thin scintillating polystyrene fibers that emit light when traversed by a charged particle. The scintillating fibers are read out by silicon photomultiplier (SiPM) arrays which are structured semi-conductor photon detectors that offer high photon efficiencies of 50%, a high gain of 10^6 electrons / photon and that are very compact in size. One silicon photomultiplier array is 1.1mm by 8.0mm in size and has 32 channels. Twenty 32mm wide and 300mm long fiber modules are arranged in four layers around a hollow cylindrical permanent magnet array.
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Because symbionts can be vertically transmitted from parent to offspring or horizontally transmitted from the environment, the presence of an aposymbiotic state suggests that transmission of the symbiont is horizontal. A classical example of a symbiotic relationship with an aposymbiotic state is the Hawaiian bobtail squid Euprymna scolopes and the bioluminescent bacteria Vibrio fischeri. While the nocturnal squid hunts, the bacteria emit light of similar intensity of the moon which camouflages the squid from predators. Juveniles are colonized within hours of hatching and Vibrio must outcompete other bacteria in the seawater through a system of recognition and infection.
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N. macrolepidotus tends to be mesopelagic until the individuals become large adults, which is when they settle down to the bathypelagic zone. The species Neoscopelus macrolepidotus is described as having a dark grey ventral surface, a greyish-silver head, pinkish-red fins, and rows of photophores along the ventral portion of the body and along the sides of the tongue. These photophores produce and emit light in the process of bioluminescence. The species generally does not exceed 25 cm in length and is found exclusively in marine environments, along various parts of the Atlantic, Indian and Pacific Oceans on continental shelves.
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Thermal radiation is electromagnetic radiation emitted from the surface of an object due to the object's internal energy. If an object is heated sufficiently, it starts to emit light at the red end of the spectrum, as it becomes red hot. Heating it further causes the color to change from red to yellow, white, and blue, as it emits light at increasingly shorter wavelengths (higher frequencies). A perfect emitter is also a perfect absorber: when it is cold, such an object looks perfectly black, because it absorbs all the light that falls on it and emits none.
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Scintillation detectors use crystals that emit light when gamma rays interact with the atoms in the crystals. The intensity of the light produced is usually proportional to the energy deposited in the crystal by the gamma ray; a well known situation where this relationship fails is the absorption of <200keV radiation by intrinsic and doped sodium iodide detectors. The mechanism is similar to that of a thermoluminescent dosimeter. The detectors are joined to photomultipliers; a photocathode converts the light into electrons; and then by using dynodes to generate electron cascades through delta ray production, the signal is amplified.
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The bandgap determines the wavelength at which LEDs can emit light and the wavelength at which photovoltaics operate most efficiently. Wide-bandgap devices therefore are useful at shorter wavelengths than other semiconductor devices. The bandgap for GaAs of 1.4 eV, for example, corresponds to a wavelength of approximately 890 nm, which is invisible infrared light (the equivalent wavelength for light energy can be determined by dividing the constant 1240 nm-eV by the energy in eV, so 1240 nm-eV/1.4 eV=886 nm). Therefore, GaAs photovoltaics are not ideal for converting shorter-wavelength visible light into electricity.
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A flame during the assessment of calcium ions in a flame photometerA sample of a material (analyte) is brought into the flame as a gas, sprayed solution, or directly inserted into the flame by use of a small loop of wire, usually platinum. The heat from the flame evaporates the solvent and breaks intramolecular bonds to create free atoms. The thermal energy also excites the atoms into excited electronic states that subsequently emit light when they return to the ground electronic state. Each element emits light at a characteristic wavelength, which is dispersed by a grating or prism and detected in the spectrometer.
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Retrieved 23 May 2014. In recent years the Microtox technology and name have undergone various different ownerships. In 2011, Microtox and related technologies was acquired by Modern Water from Strategic Diagnostics Incorporated (SDIX) for approximately $4.5 million.“MODERN WATER ACQUIRES SDIX WATER QUALITY BUSINESS, INCLUDING MICROTOX” Modern Water. 2011. Retrieved 23 May 2014. Prior to SDIX, Microtox was owned by its original developers Azur Environmental. Microtox utilizes a bioluminescent bacteria (Allivibrio fischeri) to determine the toxicity of a particular substance and/or substrate. During cellular metabolism, these bacteria naturally emit light as a part of cellular respiration, which can be measured as luminescence.
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Atoms or molecules which are exposed to light absorb light energy and re-emit light in different directions with different intensity. This phenomenon is an example of scattering, a general physical process where quanta of some form, such as light, sound, or moving particles, are forced to deviate from a straight trajectory by localized non-uniformities in the medium through which they pass. In conventional use, this also includes deviation of reflected radiation from the angle predicted by the law of reflection. Reflections of radiation that undergoes scattering are often called diffuse reflections and unscattered reflections are called specular (mirror-like) reflections.
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Cold- cathode lamps include cold-cathode fluorescent lamps (CCFLs) and neon lamps. Neon lamps primarily rely on excitation of gas molecules to emit light; CCFLs use a discharge in mercury vapor to develop ultraviolet light, which in turn causes a fluorescent coating on the inside of the lamp to emit visible light. Cold-cathode fluorescent lamps were used for backlighting of LCDs, for example computer monitors and television screens. In the lighting industry, “cold cathode” historically refers to luminous tubing larger than 20 mm in diameter and operating on a current of 120 to 240 milliamperes.
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Looking at one's surrounding environment, the vast majority of visible objects are seen primarily by diffuse reflection from their surface. This holds with few exceptions, such as glass, reflective liquids, polished or smooth metals, glossy objects, and objects that themselves emit light: the Sun, lamps, and computer screens (which, however, emit diffuse light). Outdoors it is the same, with perhaps the exception of a transparent water stream or of the iridescent colors of a beetle. Additionally, Rayleigh scattering is responsible for the blue color of the sky, and Mie scattering for the white color of the water droplets of clouds.
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For the best test-results, a monochromatic light, consisting of only a single wavelength, is used to illuminate the flats. To show the fringes properly, several factors need to be taken into account when setting up the light source, such as the angle of incidence between the light and the observer, the angular size of the light source in relation to the pupil of the eye, and the homogeneity of the light source when reflected off of the glass. Many sources for monochromatic light can be used. Most lasers emit light of a very narrow bandwidth, and often provide a suitable light source.
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Lamps are available that conform to the physical specifications for H1, but not to the regulated specifications for power consumption, light output, and/or light colour. These include high-wattage lamps, and those that emit light of a colour outside the white or selective yellow specification ranges. Such lamps are illegal throughout the industrialised world for use in regulated automotive lighting devices, and so vehicle wiring, switches, and lighting components are generally not designed or built to withstand the higher heat and power consumption from off-spec lamps. Lamps with higher-than-specified output can also create unsafe levels of glare.
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Australian Design Rule 45/01 provides for two different kinds of side marker light: a type for trucks and other large vehicles producing amber light to the front and red to the rear with no requirement to emit light to the side. intended for showing the overall length of long from in front and behind a combination, and the U.S. type amber front/red rear lamps for passenger cars. Japan's replacement of unique national rules with ECE Regulations has caused automakers to change the rear side marker colour from red to amber on their models so equipped in the Japanese market.
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Zeolites have the potential of providing precise and specific separation of gases, including the removal of H2O, CO2 and SO2 from low-grade natural gas streams. Other separations include noble gases, N2, O2, freon and formaldehyde. Zeolites were discovered to assist silver to naturally emit light, which potentially may compete with fluorescent lights or LEDs. On-board oxygen generating systems (OBOGS) and oxygen concentrators use zeolites in conjunction with pressure swing adsorption to remove nitrogen from compressed air in order to supply oxygen for aircrews at high altitudes, as well as home and portable oxygen supplies.
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While the SYBR Green dye emits its fluorescent signal simply by binding to the double- stranded DNA in solution, the TaqMan probes', molecular beacons' and scorpions' generation of fluorescence depend on Förster Resonance Energy Transfer (FRET) coupling of the dye molecule and a quencher moiety to the oligonucleotide substrates. ; SYBR Green: When the SYBR Green binds to the double-stranded DNA of the PCR products, it will emit light upon excitation. The intensity of the fluorescence increases as the PCR products accumulate. This technique is easy to use since designing of probes is not necessary given lack of specificity of its binding.
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In quantum optics, superradiance is a phenomenon that occurs when a group of N emitters, such as excited atoms, interact with a common light field. If the wavelength of the light is much greater than the separation of the emitters, then the emitters interact with the light in a collective and coherent fashion. This causes the group to emit light as a high intensity pulse (with rate proportional to N2). This is a surprising result, drastically different from the expected exponential decay (with rate proportional to N) of a group of independent atoms (see spontaneous emission).
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The species name of the sakura shrimp has not been settled. The International Code of Zoological Nomenclature uses the designation Sergia kishinouyei that Nakazawa and Terao gave it in 1915. Researchers tend to use the Sergia lucens, which Danish zoologist Hans Jacob Hansen gave it in 1922, especially since Isabella Gordon published a detailed account of the species in On New Or Imperfectly Known Species of Crustacea Macrura in 1935 using Hansen's designation. Hansen's designation comes from the genus Sergia and the Latin lucentis ("lighting"), likely referring to the sakura shrimp's phosphorescent photophores, which do emit light under certain conditions.
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He and his collaborators made many wide-ranging contributions to semiconductor devices, pioneering the design technique known as band-structure engineering. He applied it to novel low noise quantum well avalanche photodiodes, heterojunction transistors, memory devices and lasers. He and his collaborators invented and demonstrated the quantum cascade laser (QCL) (Faist, J; Capasso, F; Sivco, DL; Sirtori, C. ; Hutchinson, Al; Cho, AY "Quantum Cascade Laser" Science 264, 553-556 (1994)) . Unlike conventional semiconductor lasers, known as diode lasers, which rely on the band gap of the semiconductor to emit light, the wavelength of QCLs is determined by the energy separation between conduction band quantized states in quantum wells.
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In principle, EL lamps can be made in any color. However, the commonly used greenish color closely matches the peak sensitivity of human vision, producing the greatest apparent light output for the least electrical power input. Unlike neon and fluorescent lamps, EL lamps are not negative resistance devices so no extra circuitry is needed to regulate the amount of current flowing through them. A new technology now being used is based on multispectral phosphors that emit light from 600 to 400nm depending on the drive frequency; this is similar to the colour changing effect seen with aqua EL sheet but on a larger scale.
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The family Fulgoridae is a large group of hemipteran insects, especially abundant and diverse in the tropics, containing over 125 genera worldwide. They are mostly of moderate to large size, many with a superficial resemblance to Lepidoptera due to their brilliant and varied coloration. Various genera and species (especially the genera Fulgora and Pyrops) are sometimes referred to as lanternflies or lanthorn flies, though they do not emit light. The head of some species is produced into a hollow process (structure), resembling a snout, which is sometimes inflated and nearly as large as the body of the insect, sometimes elongated, narrow and apically upturned.
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The luciferase acts in accordance with luciferin and LBP in order to emit light but each component functions at a different pH. Luciferase and its domains are not active at pH 8 but they are extremely active at the optimum pH of 6.3 whereas LBP binds luciferin at pH 8 and releases it at pH 6.3. Consequently, luciferin is only released to react with an active luciferase when the scintillon is acidified to pH 6.3. Therefore, in order to lower the pH, voltage-gated channels in the scintillon membrane are opened to allow the entry of protons from a vacuole possessing an action potential produced from a mechanical stimulation.
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Laundry detergent fluorescing under ultraviolet light Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs), or fluorescent whitening agents (FWAs), are chemical compounds that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the electromagnetic spectrum, and re-emit light in the blue region (typically 420-470 nm) by fluorescence. These additives are often used to enhance the appearance of color of fabric and paper, causing a "whitening" effect; they make intrinsically yellow/orange materials look less so, by compensating the deficit in blue and purple light reflected by the material, with the blue and purple optical emission of the fluorophore.
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He became interested in the effect discovered by Pavel Cherenkov, that charged particles moving through water at high speeds emit light. Together with Igor Tamm, he developed a theoretical explanation: the effect occurs when charged particles travel through an optically transparent medium at speeds greater than the speed of light in that medium, causing a shock wave in the electromagnetic field. The amount of energy radiated in this process is given by the Frank–Tamm formula. The discovery and explanation of the effect resulted in the development of new methods for detecting and measuring the velocity of high-speed nuclear particles and became of great importance for research in nuclear physics.
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This grey reef shark demonstrates countershading, with its darker dorsal surface and lighter ventral surface. Sharks may have a combination of colors on the surface of their body that results in the camouflage technique called countershading. A darker color on the upper side and lighter color on the underside of the body helps prevent visual detection from predators. (For example, white on the bottom of the shark blends in with the sunlight from the surface when viewed from below.) Countershading can also be accomplished through bioluminescence in the few shark species that produce and emit light, such as the kitefin shark, a species of dogfish shark.
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With phosphor-based electronic displays (for example CRT-type computer monitors or plasma displays), non-uniform use of pixels, such as prolonged display of non- moving images (text or graphics), gaming, or certain broadcasts with tickers and flags, can create a permanent ghost-like image of these objects or otherwise degrade image quality. This is because the phosphor compounds which emit light to produce images lose their luminance with use. Uneven use results in uneven light output over time, and in severe cases can create a ghost image of previous content. Even if ghost images are not recognizable, the effects of screen burn are an immediate and continual degradation of image quality.
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The capacity of fiber optic networks has increased in part due to improvements in components, such as optical amplifiers and optical filters that can separate light waves into frequencies with less than 50 GHz difference, fitting more channels into a fiber. The erbium-doped optical amplifier (EDFA) was developed by David Payne at the University of Southampton in 1986 using atoms of the rare earth erbium that are distributed through a length of optical fiber. A pump laser excites the atoms, which emit light, thus boosting the optical signal. As the paradigm shift in network design proceeded, a broad range of amplifiers emerged because most optical communication systems used optical fiber amplifiers.
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Regular resonance Raman spectroscopy, therefore, is only sensitive to the electron energy transitions that match that of the laser used in the experiment. The molecular parts that can be studied by normal resonance Raman spectroscopy is therefore limited to those bonds that happen to have a “color” that fits somewhere into the spectrum of “colors” to which the laser used in that particular device can be tuned. Resonance hyper Raman spectroscopy, on the other hand, can excite atoms to emit light at wavelengths outside the laser’s tunable range, thus expanding the range of possible components of a molecule that can be excited and therefore studied. Resonance hyper Raman spectroscopy is one of the types of “non-linear” Raman spectroscopy.
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In principle, LIBS can analyze any matter regardless of its physical state, be it solid, liquid or gas. Because all elements emit light of characteristic frequencies when excited to sufficiently high temperatures, LIBS can (in principle) detect all elements, limited only by the power of the laser as well as the sensitivity and wavelength range of the spectrograph & detector. If the constituents of a material to be analyzed are known, LIBS may be used to evaluate the relative abundance of each constituent element, or to monitor the presence of impurities. In practice, detection limits are a function of a) the plasma excitation temperature, b) the light collection window, and c) the line strength of the viewed transition.
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Capillary electrophoresis Dye-terminator sequencing utilizes labelling of the chain terminator ddNTPs, which permits sequencing in a single reaction, rather than four reactions as in the labelled-primer method. In dye- terminator sequencing, each of the four dideoxynucleotide chain terminators is labelled with fluorescent dyes, each of which emit light at different wavelengths. Owing to its greater expediency and speed, dye-terminator sequencing is now the mainstay in automated sequencing. Its limitations include dye effects due to differences in the incorporation of the dye- labelled chain terminators into the DNA fragment, resulting in unequal peak heights and shapes in the electronic DNA sequence trace chromatogram after capillary electrophoresis (see figure to the left).
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Often, the second boundary condition is chosen to be the derivative of the wave function must be continuous across the boundary, but in the case of the quantum well the masses are different on either side of the boundary. Instead, the second boundary condition is chosen to conserve particle flux as(1/m) d\phi/dz, which is consistent with experiment. The solution to the finite well particle in a box must be solved numerically, resulting in wave functions that are sine functions inside the quantum well and exponentially decaying functions in the barriers. This quantization of the energy levels of the electrons allows a quantum well laser to emit light more efficiently than conventional semiconductor lasers.
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The design and alignment of the mirrors with respect to the medium is crucial for determining the exact operating wavelength and other attributes of the laser system. Other optical devices, such as spinning mirrors, modulators, filters, and absorbers, may be placed within the optical resonator to produce a variety of effects on the laser output, such as altering the wavelength of operation or the production of pulses of laser light. Some lasers do not use an optical cavity, but instead rely on very high optical gain to produce significant amplified spontaneous emission (ASE) without needing feedback of the light back into the gain medium. Such lasers are said to be superluminescent, and emit light with low coherence but high bandwidth.
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There are two major groups of methods for super-resolution microscopy in the far-field that can improve the resolution by a much larger factor: # Deterministic super-resolution: the most commonly used emitters in biological microscopy, fluorophores, show a nonlinear response to excitation, which can be exploited to enhance resolution. Such methods include STED, GSD, RESOLFT and SSIM. # Stochastic super-resolution: the chemical complexity of many molecular light sources gives them a complex temporal behavior, which can be used to make several nearby fluorophores emit light at separate times and thereby become resolvable in time. These methods include Super-resolution optical fluctuation imaging (SOFI) and all single-molecule localization methods (SMLM), such as SPDM, SPDMphymod, PALM, FPALM, STORM, and dSTORM.
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In the Book of Optics, al-Haytham claimed the existence of primary and secondary light, with primary light being the stronger or more intense of the two. The book describes how the essential form of light comes from self-luminous bodies and that accidental light comes from objects that obtain and emit light from those self-luminous bodies. According to Ibn al-Haytham, primary light comes from self-luminous bodies and secondary light is the light that comes from accidental objects.A detailed study on Ibn al-Haytham's theory of colors is noted in: Nader El-Bizri, 'Ibn al-Haytham et le problème de la couleur', Oriens-Occidens: Cahiers du centre d'histoire des sciences et des philosophies arabes et médiévales, C.N.R.S. 7 (2009), pp. 201–226.
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In order to measure the highest contrast possible, the dark state of the display under test must not be corrupted by light from the surroundings, since even small increments ΔL in the denominator of the ratio (LH \+ ΔL) / (LL \+ ΔL) effect a considerable reduction of that quotient. This is the reason why most contrast ratios used for advertising purposes are measured under dark-room conditions (illuminance EDR ≤ 1 lx). All emissive electronic displays (e.g. CRTs, PDPs) theoretically do not emit light in the black state (R=G=B=0%) and thus, under darkroom conditions with no ambient light reflected from the display surface into the light measuring device, the luminance of the black state is zero and thus the contrast becomes infinity.
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Such a degree of freedom is said to be "frozen out" when the thermal energy is much smaller than this spacing. For example, the heat capacity of a solid decreases at low temperatures as various types of motion become frozen out, rather than remaining constant as predicted by equipartition. Such decreases in heat capacity were among the first signs to physicists of the 19th century that classical physics was incorrect and that a new, more subtle, scientific model was required. Along with other evidence, equipartition's failure to model black-body radiation—also known as the ultraviolet catastrophe—led Max Planck to suggest that energy in the oscillators in an object, which emit light, were quantized, a revolutionary hypothesis that spurred the development of quantum mechanics and quantum field theory.
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400W Metal halide bulb compared to smaller incandescent bulb Metal halide bulbs are a type of HID light that emit light in the blue and violet parts of the light spectrum, which is similar to the light that is available outdoors during spring. Because their light mimics the color spectrum of the sun, some growers find that plants look more pleasing under a metal halide than other types of HID lights such as the HPS which distort the color of plants. Therefore, it's more common for a metal halide to be used when the plants are on display in the home (for example with ornamental plants) and natural color is preferred. Metal halide bulbs need to be replaced about once a year, compared to HPS lights which last twice as long.
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The structure floats with its arms open wide. They can be pulled shut by adding a fourth strand of DNA (D) "programmed" to stick to both of the dangling, unpaired sections of strands B and C. The closing of the tweezers was proven by tagging strand A at either end with light-emitting molecules that do not emit light when they are close together. To re-open the tweezers add a further strand (E) with the right sequence to pair up with strand D. Once paired up, they have no connection to the machine BAC, so float away. The DNA machine can be opened and closed repeatedly by cycling between strands D and E. These tweezers can be used for removing drugs from inside fullerenes as well as from a self assembled DNA tetrahedron.
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Additive color predicts perception and not any sort of change in the photons of light themselves. These predictions are only applicable in the limited scope of color matching experiments where viewers match small patches of uniform color isolated against a grey or black background. Additive color models are applied in the design and testing of electronic displays that are used to render realistic images containing diverse sets of color using phosphors that emit light of a limited set of primary colors. Examination with a sufficiently powerful magnifying lens will reveal that each pixel in CRT, LCD, and most other types of color video displays is composed of red, green, and blue light- emitting phosphors which appear as a variety of single colors when viewed from a normal distance.
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The most striking example of fluorescence occurs when the absorbed radiation is in the ultraviolet region of the spectrum, and thus invisible to the human eye, while the emitted light is in the visible region, which gives the fluorescent substance a distinct color that can be seen only when exposed to UV light. Fluorescent materials cease to glow nearly immediately when the radiation source stops, unlike phosphorescent materials, which continue to emit light for some time after. Fluorescence has many practical applications, including mineralogy, gemology, medicine, chemical sensors (fluorescence spectroscopy), fluorescent labelling, dyes, biological detectors, and cosmic-ray detection. Its most common everyday application is in energy-saving fluorescent lamps and LED lamps, where fluorescent coatings are used to convert short-wavelength UV light or blue light into longer-wavelength yellow light, thereby mimicking the warm light of energy-inefficient incandescent lamps.
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Quantum dots are photoluminescent; they are useful in displays because they emit light in specific, narrow normal distributions of wavelengths. To generate white light best suited as an LCD backlight, parts of the light of a blue-emitting LED are transformed by quantum dots into small-bandwidth green and red light such that the combined white light allows for a nearly ideal color gamut generated by the RGB color filters of the LCD panel. In addition, efficiency is improved, as intermediate colors are not present anymore and don't have to be filtered out by the color filters of the LCD screen. This can result in a display that more accurately renders colors in the visible spectrum. Other companies are also developing quantum dot solutions for displays: Nanosys, 3M as a licensee of Nanosys, QD Vision of Lexington, Massachusetts and Avantama of Switzerland.
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Third was the fact that his 1905 paper introducing light quanta and his two 1909 papers that argued for a wave- particle fusion theory approached their subjects via statistical arguments that his contemporaries "might accept as theoretical exercise—crazy, perhaps, but harmless". Most of Einstein's contemporaries adopted the position that light is ultimately a wave, but appears particulate in certain circumstances only because atoms absorb wave energy in discrete units. Bubble paradox Among the thought experiments that Einstein presented in his 1909 lecture on the nature and constitution of radiation was one that he used to point out the implausibility of the above argument. He used this thought experiment to argue that atoms emit light as discrete particles rather than as continuous waves: (a) An electron in a cathode ray beam strikes an atom in a target.
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The discrete part of the emission spectrum of hydrogen Spectrum of sunlight above the atmosphere (yellow) and at sea level (red), revealing an absorption spectrum with a discrete part (such as the line due to ) and a continuous part (such as the bands labeled ) A physical quantity is said to have a discrete spectrum if it takes only distinct values, with gaps between one value and the next. The classical example of discrete spectrum (for which the term was first used) is the characteristic set of discrete spectral lines seen in the emission spectrum and absorption spectrum of isolated atoms of a chemical element, which only absorb and emit light at particular wavelengths. The technique of spectroscopy is based on this phenomenon. Discrete spectra are contrasted with the continuous spectra also seen in such experiments, for example in thermal emission, in synchrotron radiation, and many other light- producing phenomena.
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The most widely available method of administering phototherapy to those exhibiting symptoms of SAD is through a light therapy box, which is a commercially available device designed to emit light of a brightness and colour temperature similar to sunlight. Modern devices most frequently use light emitting diodes in either a light box format or alternatively in the form of a wearable device resembling a visor or glasses. Devices that emit blue enriched white light or devices emitting only blue, only green, or a combination of blue and green wavelengths have been found as the most effective in treating SAD. The role of Occupational Therapists in the use of phototherapy when treating SAD is to ensure that clients are aware of the typical usage guidelines provided to users of light boxes and fulfil the need for clinical monitoring to ensure the appropriate doses of light by their clients.
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The company has developed and supplied lighting for the federal highway M11 (Moscow–Saint Petersburg motorway), the design of which takes into account the great distance between lampposts, and lights of the GUM façade, that emit light of a certain tone, are strictly protected from moisture, frost up to -60 °C and heat up to + 60 °C. According to the First Deputy Governor of the Rostov region, the company's lamps are used for indoor lighting of the stadium Rostov Arena. Emergency lighting equipment produced by Varton is used in the IKEA store in the Moscow suburb of Khimki, Burger King restaurants, the Moscow City Clinical Hospital №72, trade and industrial zone Altufyevo in Moscow region. As part of an experiment made together with one of the residents of innovative territorial cluster Zelenograd, the company has installed a vending machine for the sale of LED bulbs in the territory of the cluster.
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Figure 1: Sodium iodide gamma spectrum of caesium-137 () Figure 2: Sodium iodide gamma spectrum of cobalt-60 () Thallium-doped sodium iodide (NaI(Tl)) has two principal advantages: # It can be produced in large crystals, yielding good efficiency, and # it produces intense bursts of light compared to other spectroscopic scintillators. NaI(Tl) is also convenient to use, making it popular for field applications such as the identification of unknown materials for law enforcement purposes. Electron hole recombination will emit light that can re-excite pure scintillation crystals; however, the thallium dopant in NaI(Tl) provides energy states within the band gap between the conduction and valence bands. Following excitation in doped scintillation crystals, some electrons in the conduction band will migrate to the activator states; the downward transitions from the activator states will not re-excite the doped crystal, so the crystal is transparent to this radiation. An example of a NaI spectrum is the gamma spectrum of the caesium isotope —see Figure 1.
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In general, "FRET" refers to situations where the donor and acceptor proteins (or "fluorophores") are of two different types. In many biological situations, however, researchers might need to examine the interactions between two, or more, proteins of the same type—or indeed the same protein with itself, for example if the protein folds or forms part of a polymer chain of proteins or for other questions of quantification in biological cells. Obviously, spectral differences will not be the tool used to detect and measure FRET, as both the acceptor and donor protein emit light with the same wavelengths. Yet researchers can detect differences in the polarisation between the light which excites the fluorophores and the light which is emitted, in a technique called FRET anisotropy imaging; the level of quantified anisotropy (difference in polarisation between the excitation and emission beams) then becomes an indicative guide to how many FRET events have happened.
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For locations where light pollution is a consideration, such as near astronomical observatories or sea turtle nesting beaches, low-pressure sodium is preferred (as formerly in San Jose and Flagstaff, Arizona). Such lamps emit light on just two dominant spectral lines (with other much weaker lines), and therefore have the least spectral interference with astronomical observation. (Now that production of LPS lamps has ceased, consideration is being given into the use of narrow-band amber LEDs, which are on a similar color spectrum to LPS.) The yellow color of low-pressure sodium lamps also leads to the least visual sky glow, due primarily to the Purkinje shift of dark-adapted human vision, causing the eye to be relatively insensitive to the yellow light scattered at low luminance levels in the clear atmosphere. One consequence of widespread public lighting is that on cloudy nights, cities with enough lighting are illuminated by light reflected off the clouds.
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