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Reflector
Reflector may refer to: Science * Reflector, a device that causes reflection (for example, a mirror or a retroreflector) * Reflector (photography), used to control lighting contrast * Reflecting telescope * Reflector (antenna), the part of an antenna that reflects radio waves * Reflector (cipher machine), a component of some rotor machines in cryptography * Reflector (microsatellite), space debris research microsatellite * ''Reflector'', the newsletter of the Boston section of the Institute of Electrical and Electronics Engineers * Reflector, in math, the left adjoint in a reflective subcategory * Neutron reflector, in physics Computing * .NET Reflector, code browser utility * Reflector, in an electronic mailing list, a single email address that reflects (sends/remails) a copy of an email sent to it to other email addresses * Reflector router, used in a distributed reflected denial of service attack (DRDoS) * Reflector (cellular automaton), a type of pattern * Reflector, confe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retroreflector
A retroreflector (sometimes called a retroflector or cataphote) is a device or surface that reflects radiation (usually light) back to its source with minimum scattering. This works at a wide range of angle of incidence, unlike a planar mirror, which does this only if the mirror is exactly perpendicular to the wave front, having a zero angle of incidence. Being directed, the retroflector's reflection is brighter than that of a diffuse reflector. Corner reflectors and cat's eye reflectors are the most used kinds. Types There are several ways to obtain retroreflection: Corner reflector A set of three mutually perpendicular reflective surfaces, placed to form the internal corner of a cube, work as a retroreflector. The three corresponding normal vectors of the corner's sides form a basis in which to represent the direction of an arbitrary incoming ray, . When the ray reflects from the first side, say x, the ray's ''x''-component, ''a'', is reversed to −''a'', while th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Reflector
A safety reflector is a retroreflector intended for pedestrians, runners, motorized and non-motorized vehicles. A safety reflector is similar to reflective stripes that can be found on safety vests and clothing worn by road workers and rescue workers. They are sometimes erroneously called luminous badges or luminous tags, but this is incorrect as they do not themselves produce light, but only reflect it. A safety reflector aids visibility of a person or vehicle visible to on the road, as it reflects light from headlights of vehicles. Safety reflectors are especially useful where there are no streetlights. Unlike reflective stripes that are permanently fixed to clothing, the safety reflector is a stand-alone device that can be attached to any article of clothing as needed, often using a safety pin and some string. For vehicles, the reflector is usually a fixed part. In bicycles, reflectors are usually on wheels, pedals, under the seat, on the back of the luggage rack, and in fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflector (photography)
In photography and cinematography, a reflector is an improvised or specialised reflective surface used to redirect light towards a given subject or scene. Types Apart from certain highly specialized components found in enlargers, projectors and scanners, photographic reflectors fall into two main groups: Lamp reflectors Similar to a domestic lampshade, these reflectors are fixed to an artificial light source (for example, a filament bulb or flash tube) to direct and shape the otherwise scattered light, reflecting it off their concave inner surfaces and directing it towards the scene to be photographed. Although there are a large number of variants, the most common types are: * spherical, short-sided, giving a relatively broad spread of light; * parabolic, providing a tighter, parallel beam of light. The ''reflector factor'' is the ratio of the illumination provided by a lamp fitted within a reflector to the illumination provided without any reflector fitted. A matt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflector (antenna)
An antenna reflector is a device that reflects electromagnetic waves. Antenna reflectors can exist as a standalone device for redirecting radio frequency (RF) energy, or can be integrated as part of an antenna assembly. Standalone reflectors The function of a standalone reflector is to redirect electro-magnetic (EM) energy, generally in the radio wavelength range of the electromagnetic spectrum. Common standalone reflector types are * corner reflector, which reflects the incoming signal back to the direction from which it came, commonly used in radar. * ''flat reflector,'' which reflects the signal such as a mirror and is often used as a passive repeater. Integrated reflectors When integrated into an antenna assembly, the reflector serves to modify the radiation pattern of the antenna, increasing gain in a given direction. Common integrated reflector types are * parabolic reflector, which focuses a beam signal into one point or directs a radiating signal into a beam. * a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflecting Telescope
A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter objectives. Almost all of the major telescopes used in astronomy research are reflectors. Many variant forms are in use and some employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is sometimes referred to as a catoptric telescope. From the time of Newton to the 1800s, the mirror itself was made of metal usually speculum metal. This type included Newton's first designs and even the larges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflective Subcategory
In mathematics, a full subcategory ''A'' of a category ''B'' is said to be reflective in ''B'' when the inclusion functor from ''A'' to ''B'' has a left adjoint. This adjoint is sometimes called a ''reflector'', or ''localization''. Dually, ''A'' is said to be coreflective in ''B'' when the inclusion functor has a right adjoint. Informally, a reflector acts as a kind of completion operation. It adds in any "missing" pieces of the structure in such a way that reflecting it again has no further effect. Definition A full subcategory A of a category B is said to be reflective in B if for each B- object ''B'' there exists an A-object A_B and a B-morphism r_B \colon B \to A_B such that for each B-morphism f\colon B\to A to an A-object A there exists a unique A-morphism \overline f \colon A_B \to A with \overline f\circ r_B=f. : The pair (A_B,r_B) is called the A-reflection of ''B''. The morphism r_B is called the A-reflection arrow. (Although often, for the sake of brevity, we spea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Reflector
A neutron reflector is any material that reflects neutrons. This refers to elastic scattering rather than to a specular reflection. The material may be graphite, beryllium, steel, tungsten carbide, gold, or other materials. A neutron reflector can make an otherwise subcritical mass of fissile material critical, or increase the amount of nuclear fission that a critical or supercritical mass will undergo. Such an effect was exhibited twice in accidents involving the Demon Core, a subcritical plutonium pit that went critical in two separate fatal incidents when the pit's surface was momentarily surrounded by too much neutron reflective material. Nuclear reactors In a uranium graphite chain reacting pile, the critical size may be considerably reduced by surrounding the pile with a layer of graphite, since such an envelope reflects many neutrons back into the pile. To obtain a 30-year life span, the SSTAR nuclear reactor design calls for a moveable neutron reflector to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection (physics)
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The ''law of reflection'' says that for specular reflection (for example at a mirror) the angle at which the wave is incident on the surface equals the angle at which it is reflected. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves. Reflection is observed with surface waves in bodies of water. Reflection is observed with many types of electromagnetic wave, besides visible light. Reflection of VHF and higher frequencies is important for radio transmission and for radar. Even hard X-rays and gamma rays can be reflected at shallow angles with special "grazing" mirrors. Reflection of light Reflection of light is either '' specular'' (mirror-like) or '' diffuse'' (retai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internet Radio Linking Project
The Internet Radio Linking Project, also called IRLP links amateur radio stations around the world by using Voice over IP (VoIP). Each gateway consists of a dedicated computer running custom software that is connected to both a radio and the Internet. This arrangement forms what is known as an IRLP Node. Since all end users communicate using a radio as opposed to using a computer directly, IRLP has adopted the motto ''"Keeping the Radio in Amateur Radio"''. Amateur radio (or ''ham'') operators within radio range of a local node are able to use DTMF tone generators to initiate a node-to-node connection with any other available node in the world. Each node has a unique 4 digit node number in the range of 1000–8999. A real-time searchable list of all nodes worldwide (including their current status) is available anytime by viewing the IRLP Network at a Glance. As of February 2019, there are over 1,500 active nodes. IRLP connections are of two types: node to node, and node to reflect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflector (cellular Automaton)
In cellular automata such as Conway's Game of Life, a reflector is a pattern that can interact with a spaceship to change its direction of motion, without damage to the reflector pattern. In Life, many oscillators can reflect the glider Glider may refer to: Aircraft and transport Aircraft * Glider (aircraft), heavier-than-air aircraft primarily intended for unpowered flight ** Glider (sailplane), a rigid-winged glider aircraft with an undercarriage, used in the sport of gliding ...; there also exist stable reflectors composed of still life patterns that, when they interact with a glider, reflect the glider and return to their stable state. External linksNew stable 180-degree glider reflector Game of Life News, May 30, 2009 Game of Life News, May 29, 2013 Cellular automaton patterns {{Comp-sci-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflector (cipher Machine)
A reflector, in cryptology, is a component of some rotor cipher machines, such as the Enigma machine, that sends electrical impulses that have reached it from the machine's rotors, back in reverse order through those rotors. The reflector simplified using the same machine setup for encryption and decryption, but it creates a weakness in the encryption: with a reflector the encrypted version of a given letter can never be that letter itself. That limitation aided World War II code breakers in cracking Enigma encryption. The comparable WW II U.S. cipher machine, SIGABA In the history of cryptography, the ECM Mark II was a cipher machine used by the United States for message encryption from World War II until the 1950s. The machine was also known as the SIGABA or Converter M-134 by the Army, or CSP-888/889 by the ..., did not include a reflector. Other names The reflector is also known as the reversing drum or, from the German, the ''Umkehrwalze'' or ''UKW''. {{crypto-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mirror
A mirror or looking glass is an object that Reflection (physics), reflects an image. Light that bounces off a mirror will show an image of whatever is in front of it, when focused through the lens of the eye or a camera. Mirrors reverse the direction of the image in an equal yet opposite angle from which the light shines upon it. This allows the viewer to see themselves or objects behind them, or even objects that are at an angle from them but out of their field of view, such as around a corner. Natural mirrors have existed since prehistoric times, such as the surface of water, but people have been manufacturing mirrors out of a variety of materials for thousands of years, like stone, metals, and glass. In modern mirrors, metals like silver or aluminium are often used due to their high reflectivity, applied as a thin coating on glass because of its naturally smooth and very Hardness (materials science), hard surface. A mirror is a Wave (physics), wave reflector. Light consis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
