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Dielectric Barrier Discharge
Dielectric-barrier discharge (DBD) is the electrical discharge between two electrodes separated by an insulating dielectric barrier. Originally called silent (inaudible) discharge and also known as ozone production discharge or partial discharge, it was first reported by Ernst Werner von Siemens in 1857.Kogelschatz, Ulrich, Baldur Eliasson, and Walter EgliFrom ozone generators to flat television screens: history and future potential of dielectric-barrier discharges Pure Applied Chemistry, Vol. 71, No. 10, pp. 1819–1828, 1999. Retrieved on 5 August 2007. Process The process normally uses high voltage alternating current, ranging from lower RF to microwave frequencies. However, other methods were developed to extend the frequency range all the way down to the DC. One method was to use a high resistivity layer to cover one of the electrodes. This is known as the resistive barrier discharge.M. Laroussi, I. Alexeff, J. P. Richardson, and F. F. Dyer " The Resistive Barrier D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DBD Plasma Actuators2
DBD may refer to: Technology * Database description, a type of OSPF packet * Deep borehole disposal, a technique to dispose of nuclear waste * Defective by Design, an anti-DRM initiative * Dielectric barrier discharge, a type of electrical discharge * DNA-binding domain, a protein motif * DataBase Driver, a plug-in module for Perl DBI * dB(D), D-weighted decibel, a decibel weighting value * Donation after brain death, of beating heart cadaver organ donation Other uses * Day by Day Christian Ministries * Death Before Dishonor (band), an American hardcore punk band * ''Dead by Daylight'', an asymmetric survival horror video game * Democratic Farmers' Party of Germany or Demokratische Bauernpartei Deutschlands See also {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma (physics)
Plasma () is a state of matter characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, mostly in stars (including the Sun), but also dominating the rarefied intracluster medium and Outer space#Intergalactic space, intergalactic medium. Plasma can be artificially generated, for example, by heating a neutral gas or subjecting it to a strong electromagnetic field. The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern devices and technologies, such as plasma display, plasma televisions or plasma etching. Depending on temperature and density, a certain number of neutral particles may also be present, in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wettability
Wetting is the ability of a liquid to displace gas to maintain contact with a solid surface, resulting from intermolecular interactions when the two are brought together. These interactions occur in the presence of either a gaseous phase or another liquid phase not miscible with the wetting liquid. The degree of wetting (wettability) is determined by a force balance between adhesive and cohesive forces. There are two types of wetting: non-reactive wetting and reactive wetting. Wetting is important in the bonding or adherence of two materials. The wetting power of a liquid, and surface forces which control wetting, are also responsible for related effects, including capillary effects. Surfactants can be used to increase the wetting power of liquids such as water. Wetting has gained increasing attention in nanotechnology and nanoscience research, following the development of nanomaterials over the past two decades (i.e., graphene, carbon nanotube, boron nitride nanomesh). E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flat Panel Display
A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipment. Flat-panel displays are thin, lightweight, provide better linearity and are capable of higher resolution than typical consumer-grade TVs from earlier eras. They are usually less than thick. While the highest resolution for consumer-grade CRT televisions was 1080i, many interactive flat panels in the 2020s are capable of 1080p and 4K resolution. In the 2010s, portable consumer electronics such as laptops, mobile phones, and portable cameras have used flat-panel displays since they consume less power and are lightweight. As of 2016, flat-panel displays have almost completely replaced CRT displays. Most 2010s-era flat-panel displays use LCD or light-emitting diode (LED) technologies, sometimes combined. Most LCD screens are back-lit with color filters used to display colors. In many cases, fla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adhesion
Adhesion is the tendency of dissimilar particles or interface (matter), surfaces to cling to one another. (Cohesion (chemistry), Cohesion refers to the tendency of similar or identical particles and surfaces to cling to one another.) The forces that cause adhesion and cohesion can be divided into several types. The intermolecular forces responsible for the function of various kinds of stickers and sticky tape fall into the categories of chemical adhesion, dispersive adhesion, and diffusive adhesion. In addition to the cumulative magnitudes of these intermolecular forces, there are also certain emergent mechanical effects. Surface energy Surface energy is conventionally defined as the work (physics), work that is required to build an area of a particular surface. Another way to view the surface energy is to relate it to the work required to cleave a bulk sample, creating two surfaces. If the new surfaces are identical, the surface energy γ of each surface is equal to h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductor
A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping levels are present in the same crystal, they form a semiconductor junction. The behavior of charge carriers, which include electrons, ions, and electron holes, at these junctions is the basis of diodes, transistors, and most modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called " metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second-most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits, and others. Silicon is a critical element for fabricating most electronic circuits. Semiconductor devices can display a range of different useful properties, such as passing current more easil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compound (chemistry), compounds, produces unique physical property, physical properties including toughness, high rubber elasticity, elasticity, viscoelasticity, and a tendency to form Amorphous solid, amorphous and crystallization of polymers, semicrystalline structures rath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Cleaning
Plasma cleaning is the removal of impurities and contaminants from surfaces through the use of an energetic plasma (physics), plasma or dielectric barrier discharge (DBD) plasma created from gaseous species. Gases such as argon and oxygen, as well as mixtures such as air and hydrogen/nitrogen are used. The plasma is created by using high frequency voltages (typically kHz to >MHz) to ionise the low pressure gas (typically around 1/1000 atmospheric pressure), although atmospheric pressure plasmas are now also common. Methods In plasma, gas atoms are excited to higher energy states and also ionized. As the atoms and molecules 'relax' to their normal, lower energy states they release a photon of light, this results in the characteristic “glow” or light associated with plasma. Different gases give different colors. For example, oxygen plasma emits a light blue color. A plasma’s activated species include atoms, molecules, ions, electrons, radical (chemistry), free radicals, metas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow Control (fluid)
Flow control is a field of fluid dynamics. It involves a small configuration change to serve an ideally large engineering benefit, like drag reduction, lift increase, mixing enhancement or noise reduction. This change may be accomplished by passive or active devices. Passive vs active Passive devices by definition require no energy. Passive techniques include turbulators or roughness elements geometric shaping, the use of vortex generators, and the placement of longitudinal grooves or riblets on airfoil surfaces. Active control requires actuators that require energy and may operate in a time-dependent manner. Active flow control includes steady or unsteady suction or blowing, the use of synthetic jets, valves and plasma actuators. Actuation may be pre-determined (open-loop control) or be dependent on monitoring sensors (closed-loop control). Aircraft wings Airplane wing performance has a substantial effect on not only runway length, approach speed, climb rate, cargo capa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerodynamics
Aerodynamics () is the study of the motion of atmosphere of Earth, air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dynamics and its subfield of gas dynamics, and is an important domain of study in aeronautics. The term ''aerodynamics'' is often used synonymously with gas dynamics, the difference being that "gas dynamics" applies to the study of the motion of all gases, and is not limited to air. The formal study of aerodynamics began in the modern sense in the eighteenth century, although observations of fundamental concepts such as aerodynamic drag were recorded much earlier. Most of the early efforts in aerodynamics were directed toward achieving Aircraft#Heavier-than-air – aerodynes, heavier-than-air flight, which was first demonstrated by Otto Lilienthal in 1891. Since then, the use of aerodynamics through mathematical analysis, empirical approximations, wind tunnel experimentation, and computer si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Display
A plasma display panel is a type of flat-panel display that uses small cells containing Plasma (physics), plasma: Ionization, ionized gas that responds to electric fields. Plasma televisions were the first large (over diagonal) flat-panel displays to be released to the public. Until about 2007, plasma displays were commonly used in large televisions. By 2013, they had lost nearly all market share due to competition from low-cost liquid-crystal displays (LCDs). Manufacturing of plasma displays for the United States retail market ended in 2014, and manufacturing for the Chinese market ended in 2016. Plasma displays are obsolete, having been superseded in most if not all aspects by OLED displays. Competing display technologies include cathode-ray tube (CRT), organic light-emitting diode (OLED), CRT projectors, AMLCD, digital light processing (DLP), SED-tv, LED display, field emission display (FED), and quantum dot display (QLED). History Early development Kálmán Tihanyi, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Excimer Lamp
An excimer lamp (or excilamp) is a source of ultraviolet light based on spontaneous emission of excimer (exciplex) molecules. Introduction Excimer lamps are quasimonochromatic light sources operating over a wide range of wavelengths in the ultraviolet (UV) and vacuum ultraviolet (VUV) spectral regions. Operation of an excimer lamp is based on the formation of ''excited dimers'' (excimers), which spontaneously transiting from the excited state to the ground state result in the emission of UV photons. The spectral maximum of excimer lamp radiation is specified by a working excimer molecule: : Excimers are diatomic molecules (dimers) or polyatomic molecules that have stable excited electronic states and an unbound or weakly bound (thermally unstable) ground state. Initially, only homonuclear diatomic molecules with a stable excited state but a repulsive ground state were called excimers (excited dimers). The term "excimer" was later extended to refer any polyatomic molecule with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
