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c_sd5zhmfivby8 | In operator theory, a bounded operator T on a Hilbert space is said to be nilpotent if Tn = 0 for some n. It is said to be quasinilpotent or topologically nilpotent if its spectrum σ(T) = {0}. | Nilpotent operator |
c_uwpos28yonsn | In operator theory, a bounded operator T: X → Y between normed vector spaces X and Y is said to be a contraction if its operator norm ||T || ≤ 1. This notion is a special case of the concept of a contraction mapping, but every bounded operator becomes a contraction after suitable scaling. The analysis of contractions p... | Contraction (operator theory) |
c_ibivo1z76nxy | In operator theory, a branch of mathematics, a positive-definite kernel is a generalization of a positive-definite function or a positive-definite matrix. It was first introduced by James Mercer in the early 20th century, in the context of solving integral operator equations. Since then, positive-definite functions and... | Positive-definite kernel function |
c_x0naburkmhko | In operator theory, a branch of mathematics, every Banach algebra can be associated with a group called its abstract index group. | Abstract index group |
c_122e99vu4913 | In operator theory, a dilation of an operator T on a Hilbert space H is an operator on a larger Hilbert space K, whose restriction to H composed with the orthogonal projection onto H is T. More formally, let T be a bounded operator on some Hilbert space H, and H be a subspace of a larger Hilbert space H' . A bounded op... | Dilation (operator theory) |
c_k9yuhlqmv8tb | Namely, that a dilation satisfy the following (calculus) property: P H f ( V ) | H = f ( T ) {\displaystyle P_{H}\;f(V)|_{H}=f(T)} where f(T) is some specified functional calculus (for example, the polynomial or H∞ calculus). The utility of a dilation is that it allows the "lifting" of objects associated to T to the le... | Dilation (operator theory) |
c_syrqh00hlgl1 | In operator theory, a multiplication operator is an operator Tf defined on some vector space of functions and whose value at a function φ is given by multiplication by a fixed function f. That is, for all φ in the domain of Tf, and all x in the domain of φ (which is the same as the domain of f). This type of operator i... | Multiplication operator |
c_5zhk2dz35ses | In operator theory, a set X ⊆ C {\displaystyle X\subseteq \mathbb {C} } is said to be a spectral set for a (possibly unbounded) linear operator T {\displaystyle T} on a Banach space if the spectrum of T {\displaystyle T} is in X {\displaystyle X} and von-Neumann's inequality holds for T {\displaystyle T} on X {\display... | Spectral set |
c_i954dvxyfinx | In operator theory, an area of mathematics, Douglas' lemma relates factorization, range inclusion, and majorization of Hilbert space operators. It is generally attributed to Ronald G. Douglas, although Douglas acknowledges that aspects of the result may already have been known. The statement of the result is as follows... | Douglas' lemma |
c_o0n9m3uilhyi | In operator theory, particularly the study of PDEs, operators are particularly easy to understand and PDEs easy to solve if the operator is diagonal with respect to the basis with which one is working; this corresponds to a separable partial differential equation. Therefore, a key technique to understanding operators i... | Scalar transformation |
c_4wvikojl791y | In operator theory, quasinormal operators is a class of bounded operators defined by weakening the requirements of a normal operator. Every quasinormal operator is a subnormal operator. Every quasinormal operator on a finite-dimensional Hilbert space is normal. | Quasinormal operator |
c_i7lzhvjrv5hx | In operator theory, the Gelfand–Mazur theorem is a theorem named after Israel Gelfand and Stanisław Mazur which states that a Banach algebra with unit over the complex numbers in which every nonzero element is invertible is isometrically isomorphic to the complex numbers, i. e., the only complex Banach algebra that is ... | Gelfand–Mazur theorem |
c_hfb1t0inbrpu | So a = λ · 1. This gives an isomorphism from A to C. The theorem can be strengthened to the claim that there are (up to isomorphism) exactly three real Banach division algebras: the field of reals R, the field of complex numbers C, and the division algebra of quaternions H. This result was proved first by Stanisław Maz... | Gelfand–Mazur theorem |
c_6qvhw93p6fhj | In operator theory, the commutant lifting theorem, due to Sz.-Nagy and Foias, is a powerful theorem used to prove several interpolation results. | Commutant lifting theorem |
c_eppf9cnp67kc | In operator theory, von Neumann's inequality, due to John von Neumann, states that, for a fixed contraction T, the polynomial functional calculus map is itself a contraction. | Von Neumann's inequality |
c_6ndaaoxlue7n | In ophthalmic terminology, "aspheric lens" specifically refers to a subclass of aspheric lens. Designs that feature "flatter" curves trade optical quality for cosmetic appearance. By using a non-spheric lens shape, an aspheric lens attempts to correct the error induced by flattening the lens. Typically, the design focu... | Ophthalmic lens |
c_9ylahhulyc42 | This is of primary benefit to farsighted individuals, whose lenses have a thick center. An atoric lens design refers to a lens with a more complex aspheric lens design. An atoric lens design can address errors over more corners of the lens, not just the horizontal and vertical axis. A toric lens is designed to compensa... | Ophthalmic lens |
c_9oquqze5xsf5 | In ophthalmology and optometry, a slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an examination of the anterior segment and posterior segment of the human eye, wh... | Slit lamp |
c_xik8c75z4sq0 | In ophthalmology and optometry, there are two major forms of eye exam using ultrasound: A-scan ultrasound biometry, is commonly referred to as an A-scan (amplitude scan). A-mode provides data on the length of the eye, which is a major determinant in common sight disorders, especially for determining the power of an int... | Ultrasound scan |
c_w9y999y91i33 | In ophthalmology, OCE could be utilized to characterize the mechanical properties of the cornea in order to diagnose related ocular disease: especially to diagnose and assess the properties of keratoconus, which provides necessary information to establish adaptive biomechanical models of the cornea for the optimization... | Optical coherence elastography |
c_qkn8vce2dl20 | In ophthalmology, choroidal neovascularization is the formation of a microvasculature within the innermost layer of the choroid of the eye. Neovascularization in the eye can cause a type of glaucoma (neovascularization glaucoma) if the new blood vessels' bulk blocks the constant outflow of aqueous humour from inside th... | Neovascularization |
c_p4yetuxm0n50 | In ophthalmology, cryoextraction is a form of intracapsular cataract extraction in which a cryoextractor, a special type of cryoprobe, is used to freeze the crystalline lens and pull it intact from the eye. Dr. Charles Kelman is credited with pioneering this surgical method in 1962. It can also be used in the treatment... | Cryoextraction (medicine) |
c_zf4ro1t1afdd | In ophthalmology, glued intraocular lens or glued IOL is a surgical technique for implantation, with the use of biological glue, of a posterior chamber IOL (intraocular lens) in eyes with deficient or absent posterior capsules. A quick-acting surgical fibrin sealant derived from human blood plasma, with both hemostatic... | Glued intraocular lens |
c_3a7f7fbz844n | In ophthalmology, pannus refers to the growth of blood vessels into the peripheral cornea. In normal individuals, the cornea is avascular. Chronic local hypoxia (such as that occurring with overuse of contact lenses) or inflammation may lead to peripheral corneal vascularization, or pannus. | Pannus |
c_wbcip23sdti8 | Pannus may also develop in diseases of the corneal stem cells, such as aniridia. It is often resolved by peritomy. == References == | Pannus |
c_pqbvlu4bfchm | In ophthalmology, tonus may be a central consideration in eye surgery, as in the manipulation of extraocular muscles to repair strabismus. Tonicity aberrations are associated with many diseases of the eye (e.g. Adie syndrome). | Muscle tone |
c_kkqjp9ziciuo | In opponent color spaces in which two of the axes are perceptually orthogonal to lightness, such as the CIE 1976 (L*, a*, b*) (CIELAB) and 1976 (L*, u*, v*) (CIELUV) color spaces, hue may be computed together with chroma by converting these coordinates from rectangular form to polar form. Hue is the angular component o... | Hue angle |
c_p6ub4rwr15uy | In opposition to entity theory, individuals with an incremental (also referred to as "flexible," and "malleable") view of intelligence believe that intelligence is adjustable. The belief is that intelligence is the result of hard work and the use of the appropriate strategies. This is particularly adaptive because rath... | Goal orientation |
c_8k8lsb2zq43g | In opposition to five-membered cyclic carbonate, the six-membered ones like trimethylene carbonate are thermodynamically less stable than its polymer, undergoing the ring-opening polymerization with retention of CO 2 {\displaystyle _{2}} in the polymer structure, and generation an aliphatic polycarbonate. Ring-opening ... | Poly(trimethylene carbonate) |
c_i5302japahnv | In opposition to the conundrum of the valence theories of mood-congruence, proponents such as Paula Niedenthal propose a theory of categorical conception. The theory of categorical conception argues that mood-congruence of current affective states and memory recall are subject to attentional strengths and deficits in c... | Mood congruence |
c_op3ammil4k7z | The attention can be implicitly or explicitly encoded. For instance, if an individual is sad, they will pay more attention to the aspects of their environment that are congruent with sadness such as melancholy or dreary weather. Therefore, if someone is frequently depressed, they are more likely to pay attention to rep... | Mood congruence |
c_64hvwkpn4yzv | In opposition to the modern revisers, Meredith Kline reemphasized the idea of a covenant of works as expressed in the Westminster Confession of Faith 7.2 as a means to protect a gospel of grace. Kline wrote: If meritorious works could not be predicated of Jesus Christ as second Adam, then obviously there would be no me... | Covenant Theology |
c_bvekiotplzwk | The gospel truth, however, is that Christ has performed the one act of righteousness and by His obedience of the one the many are made righteous (Rom 5:18, 19)… . Underlying Christ's mediatorship of a covenant of grace for the salvation of believers is His earthly fulfillment, through meritorious obedience, of His heav... | Covenant Theology |
c_q27btdfadjqb | Kline, Michael Horton, and others have sought to uphold the distinction of two sorts of covenant traditions: one based on merit, earned by obedience to law (works), and the other on promise (grace). While the consensus in Calvinist theology is that works are antithetical to grace as the means of justification, differen... | Covenant Theology |
c_e7d9ox99ruza | Since this is understood to be an impossible task for the corrupted sinner, it is Christ who perfectly obeyed the law in fulfillment of the covenant of works. Jesus, earning the reward, graciously bestows it to His people (cf. Luke 22:29). | Covenant Theology |
c_ggmozulzxqka | For example, R. C. Sproul writes, "Man's relationship to God in creation was based on works. What Adam failed to achieve, Christ, the second Adam, succeeded in achieving. Ultimately the only way one can be justified is by works." | Covenant Theology |
c_vjbfoe90u7c9 | The sinner is thus saved by Christ's works and not his own. Right standing before God is then due to an alien or imputed righteousness received by faith, not by personal faithfulness which is the fruition of salvation and not its ground. On the other hand, Calvinist theologians more in line with Murray tend to say that... | Covenant Theology |
c_ei2r9493gro2 | Consequently, works are the necessary response to grace and not the precondition for it. For example, Michael Williams writes, "The function of law within Scripture is the maintenance of relationship, not the creation of relationship. Legal obligation is not the precondition for life and relationship. Rather, life and ... | Covenant Theology |
c_04ruiei2b2zy | In opposition, some feminists believe sex-positivity perceives disadvantage in women but makes them easier to oppress. A large religious—particularly Abrahamic—conservative opposition to sex-positivity sees human sexuality as a destructive force except under the contract of a marriage. Sexual acts are ranked hierarchic... | Sex-positive movement |
c_eqnkuldwejmy | These feminists insist they are "sex-critical" rather than "sex-negative". Scholar, Verkerk, acknowledges this by stating that "there are both harmful and liberating aspects of female sexual objectification and an accurate account of it must consider both". | Sex-positive movement |
c_mx758m0w9wiw | Critics also take issue with the commodification of sexuality. Women are told both to invest in western standards of beauty and sexualization while also becoming "consumable objects themselves." | Sex-positive movement |
c_2jw7ortusqcd | Sex-positive feminism has also been criticized for its emphasis on defeating the patriarchal gender norms through personal life choices, "rather than to dismantle, critique, expose, or challenge systematic discrimination and violence." The SlutWalk has received criticism of its efficacy as an activist event. SlutWalk's... | Sex-positive movement |
c_vkg5epsldzmu | Despite the aim of the slut-walk, critics point out that the word "slut" had not been reclaimed. Rather, the word slut had become reified. Critics of the SlutWalk also suggest that the focus on revealing clothing "ultimately displace the sombre and deadly issues of rape, domestic violence, sexual abuse, and street hara... | Sex-positive movement |
c_ux0wwrgrdpvg | In opposition, there have been legacy villains in fiction as well. In comics, examples are DC's Blockbuster, Captain Boomerang, and Clayface; Marvel's Green Goblin, Mysterio, and Electro. In Disney's Gargoyles, a multi-generational line of villains known as the Hunter share the same scar on their faces. == References =... | Legacy hero |
c_ylymey2tt5z9 | In oppositionIn June 2020, Baskut Tuncak, United Nations's Special Rapporteur on toxics and human rights, wrote on Japan's Kyodo News that the communities of Fukushima have the right not to be exposed deliberately to additional radioactive contamination." Greenpeace and five other UN Rapporteurs (including Clément Nyal... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_slpekxkyy280 | Various governments have voiced concerns, including the governments of South Korea, North Korea, Taiwan, China, Russia, Germany, the Philippines, New Zealand, Belize, Costa Rica, Dominican Republic, El Salvador, Guatemala, Honduras, Nicaragua, Panama, and Mexico. In June 2021, at least 70 U.S. | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_r32cfbsm10dy | civic groups condemned Japan's wastewater discharge plan, and 17 civic organizations from various countries held protests in Berlin. In January 2023, the U.S. National Association of Marine Laboratories expressed their opposition to the plan and stated that “there was a lack of adequate and accurate scientific data sup... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_r6n13kzp6hvx | There were concerns about the health impacts of long-term, low-dose exposure to tritium as a result of Japan's multi-decade plan to release the wastewater into the sea. In May 2023, Jinbo Party leader Yoon Hee-sook said that the Korean inspection team that visited the treatment facilities had failed to address the "bio... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_hfr3pcp436ro | The South Korean government had banned seafood from the waters near Fukushima and says it will closely monitor the radioactivity level of salt farms. A similar salt rush occurred in China, after the discharge began. In the months leading up to the start of discharge, over 80 per cent of South Koreans surveyed opposed t... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_eix38h7e4r24 | In August 2023, the Green Party of the United States issued a press release opposing the discharge. In the same month, Shaun Burnie, senior nuclear specialist for Greenpeace, accused the Japanese government and TEPCO of diverting attention away from the radiation levels in the waste water from the nuclear plant by emph... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_n5rzk70vksw0 | According to the organisers, about 50,000 people gathered in Seoul. Some attempted to storm the Japanese embassy there. Japanese shops reported receiving spam calls from China after the start of the discharge. | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_uhoys37o1o8b | The Japanese government responded by summoning the deputy minister at the Chinese embassy. Chinese state media outlets CCTV and China Global Television Network ran paid ads denouncing the water release on Facebook and Instagram in multiple countries and languages. Critics labeled it part of a concerted disinformation c... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_u41y6wk23ql7 | The Chinese government, Hong Kong, Macau, and the South Korean government have banned aquatic imports from some or all regions of Japan.In supportU.S. Secretary of State Antony Blinken stated on 13 April 2021, “We thank Japan for its transparent efforts in its decision to dispose of the treated water”. US Climate Envoy... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_gu6f569h8hr9 | In February 2023, President of the Federated States of Micronesia David Panuelo said he trusted Japan's intention and capabilities but would continue to consult with Japan to ensure the water's safety. Micronesia had previously expressed strong opposition to Japan releasing the water. On 14 June 2023, Palau President S... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_29g2tmx182jp | expressed understanding of Japan's plan to release the treated waste water into the sea, remarking "The people who would be impacted most are their own people. And if it's acceptable to their people, it should be acceptable to all of us." On 23 August 2023, Fijian Prime Minister Sitiveni Rabuka expressed support for th... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_wi33lk8ba2w2 | In July 2023, the IAEA released its conclusion that Japan's plans to slowly discharge the treated wastewater are in accordance with the relevant international safety standards. It stopped short of endorsing the decision, however. Arjun Makhijani, president of the Institute for Energy and Environmental Research, critici... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_df0c6f9tqaoz | On 9 August 2023, during a Nuclear Non-Proliferation Treaty (NPT) committee, Australia, France, Italy, Malaysia, United Kingdom, and the United States expressed support for the IAEA report released in July. Australia said it was "independent, impartial and science-based" and trusts it completely, the UK also said it ca... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_e52c4kn1vgxf | In August 2023, a panel of five independent experts consulting for the Pacific Islands Forum was split on the issue of discharge. Some had no issue with it, saying it would not harm the Pacific. Two of the panelists said trying to obtain information from Japan was difficult and its data had "red flags". | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_xsox9dtbyr7b | In the same month, in an article in The Japan Times, they advised Japan to postpone the release of the wastewater as they believed the "full extent of the nuclear isotopes in the damaged plant's tanks" needed more study. Ferenc Dalnoki-Veress, a scientist-in-residence at the Middlebury Institute of International Studie... | Discharge of radioactive water of the Fukushima Daiichi Nuclear Power Plant |
c_djj1s2mkaok4 | In optical astronomy, interferometry is used to combine signals from two or more telescopes to obtain measurements with higher resolution than could be obtained with either telescopes individually. This technique is the basis for astronomical interferometer arrays, which can make measurements of very small astronomical... | Astronomical optical interferometry |
c_j2b3ypeaw2i3 | These include radio telescope arrays such as VLA, VLBI, SMA, LOFAR and SKA, and more recently astronomical optical interferometer arrays such as COAST, NPOI and IOTA, resulting in the highest resolution optical images ever achieved in astronomy. The VLT Interferometer is expected to produce its first images using apert... | Astronomical optical interferometry |
c_g1mfkm27phux | In optical astronomy, stray light from sky glow can limit the ability to detect faint objects. In this sense stray light is light from other sources that is focused to the same place as the faint object. Stray light is a major issue in the design of a coronagraph, used for observing the Sun's corona. | Stray light |
c_83e8kjaxf9ho | In optical astronomy, the air mass provides an indication of the deterioration of the observed image, not only as regards direct effects of spectral absorption, scattering and reduced brightness, but also an aggregation of visual aberrations, e.g. resulting from atmospheric turbulence, collectively referred to as the q... | Air mass (astronomy) |
c_o5ti4dhtyvvb | The Greenwood frequency and Fried parameter, both relevant for adaptive optics, depend on the air mass above them (or more specifically, on the zenith angle). In radio astronomy the air mass (which influences the optical path length) is not relevant. The lower layers of the atmosphere, modeled by the air mass, do not s... | Air mass (astronomy) |
c_v0udnq9ff15t | Instead, some radio waves are affected by the ionosphere in the upper atmosphere. Newer aperture synthesis radio telescopes are especially affected by this as they “see” a much larger portion of the sky and thus the ionosphere. In fact, LOFAR needs to explicitly calibrate for these distorting effects (van der Tol & van... | Air mass (astronomy) |
c_ldro7cpzsvd1 | In optical burst switching, offset time is the time between the burst header/control packet. The offset time used in one-way reservation schemes allows the network time to schedule the burst and set-up resources prior to burst arrival is sent into the network. The offset time can be varied to allow the network time to ... | Offset time |
c_gihkibt1aeji | In optical communications, intensity modulation (IM) is a form of modulation in which the optical power output of a source is varied in accordance with some characteristic of the modulating signal. The envelope of the modulated optical signal is an analog of the modulating signal in the sense that the instantaneous pow... | Intensity modulation |
c_lf7okxd5a0sw | Bell Laboratories had a working, but impractical, system in 1969. Heterodyne and homodyne systems are of interest because they are expected to produce an increase in sensitivity of up to 20 dB allowing longer hops between islands for instance. Such systems also have the important advantage of very narrow channel spacin... | Intensity modulation |
c_ayx9tvegagkl | In optical communications, the part of the infrared spectrum that is used is divided into seven bands based on availability of light sources, transmitting/absorbing materials (fibers), and detectors: The C-band is the dominant band for long-distance telecommunication networks. The S and L bands are based on less well e... | Infrared |
c_6y618ewfdtu6 | In optical design jargon, an apodization function is used to purposely change the input intensity profile of an optical system, and it may be a complicated function to tailor the system to certain properties. Usually, it refers to a non-uniform illumination or transmission profile that approaches zero at the edges. | Apodization |
c_42iz0lbf7l1m | In optical disc authoring, there are multiple modes for recording, including Disc-At-Once, Track-At-Once, and Session-At-Once. | Optical disc recording modes |
c_qich8i38lfga | In optical disc manufacturing, replication is the process of producing discs via methods that do not involve "burning" blank CD, DVD or other discs; the latter is known as duplication. The replication of optical discs involves: the creation of a glass master from a client original master. the creation of a nickel stamp... | Glass master |
c_p88cas52me2h | In optical engineering and telecommunications engineering, the flick is a unit of spectral radiance. One flick corresponds to a spectral radiance of 1 watt per steradian per square centimeter of surface per micrometer of span in wavelength (W·sr−1·cm−2·μm−1). This is equivalent to 1010 watts per steradian per cubic met... | Flick (physics) |
c_hvrtgruvwylk | In optical engineering, an objective is an optical element that gathers light from an object being observed and focuses the light rays from it to produce a real image of the object. Objectives can be a single lens or mirror, or combinations of several optical elements. They are used in microscopes, binoculars, telescop... | Objective (optics) |
c_l5rfoh2bhivi | In optical fiber communications, a muxponder is the element that sends and receives the optical signal on a fiber in much the same way as a transponder except that the muxponder has the additional functionality of multiplexing multiple sub-rate client interfaces onto the line interface. == References == | Muxponder |
c_ocrijdt1i73h | In optical fiber communications, a transponder is the element that sends and receives the optical signal from a fiber. A transponder is typically characterized by its data rate and the maximum distance the signal can travel. The term "transponder" can apply to different items with important functional differences, ment... | Transponder |
c_qdah1yltqrlo | In this view, transponders provide easier-to-handle lower-rate parallel signals, but are bulkier and consume more power than transceivers. according to another description, transceivers are limited to providing an electrical-optical function only (not differentiating between serial or parallel electrical interfaces), w... | Transponder |
c_9zc0pzcm24lz | In optical fiber technology, the substitution method is a method of measuring the transmission loss of a fiber. It consists of: using a stable optical source, at the wavelength of interest, to drive a mode scrambler, the output of which overfills (drives) a 1 to 2 meter long reference fiber having physical and optical ... | Substitution method |
c_j8k95um3qc95 | In optical fibers, attenuation is the rate at which the signal light decreases in intensity. For this reason, glass fiber (which has a low attenuation) is used for long-distance fiber optic cables; plastic fiber has a higher attenuation and, hence, shorter range. There also exist optical attenuators that decrease the s... | Natural attenuation |
c_w6g204o5ppr8 | Attenuation of light is also important in physical oceanography. This same effect is an important consideration in weather radar, as raindrops absorb a part of the emitted beam that is more or less significant, depending on the wavelength used. Due to the damaging effects of high-energy photons, it is necessary to know... | Natural attenuation |
c_ofmgapei3w2d | In addition, gamma radiation is used in cancer treatments where it is important to know how much energy will be deposited in healthy and in tumorous tissue. In computer graphics attenuation defines the local or global influence of light sources and force fields. In CT imaging, attenuation describes the density or darkn... | Natural attenuation |
c_wfoqo8lr1fht | In optical interferometers such as the Michelson interferometer, Mach–Zehnder interferometer, or Sagnac interferometer, one splits an electric field into two components, introduces a time delay to one of the components, and then recombines them. The intensity of resulting field is measured as a function of the time del... | Degree of coherence |
c_x553he6h0izr | The visibility ranges from zero, for incoherent electric fields, to one, for coherent electric fields. Anything in between is described as partially coherent. Generally, g ( 1 ) ( 0 ) = 1 {\displaystyle g^{(1)}(0)=1} and g ( 1 ) ( τ ) = g ( 1 ) ( − τ ) ∗ {\displaystyle g^{(1)}(\tau )=g^{(1)}(-\tau )^{*}} . | Degree of coherence |
c_h1rskcdq0fys | In optical interferometry, homodyne signifies that the reference radiation (i.e. the local oscillator) is derived from the same source as the signal before the modulating process. For example, in a laser scattering measurement, the laser beam is split into two parts. One is the local oscillator and the other is sent to... | Homodyne detection |
c_cs2rj09bu8x9 | In optical mesh networks, nodes are junctions of fiber spans. Some nodes might contain highly sophisticated routing equipment— while others may be just a patch panel. Whatever the case, a node is a shared risk node group—because if the node fails, the failure affects all signals through that particular node. | Shared Risk Resource Group |
c_cnzypbjy4nwq | In optical microscopy, dark-field describes an illumination technique used to enhance the contrast in unstained samples. It works by illuminating the sample with light that will not be collected by the objective lens and thus will not form part of the image. This produces the classic appearance of a dark, almost black,... | Dark field |
c_ltpxmh418udb | In optical mineralogy and petrography, a thin section (or petrographic thin section) is a thin slice of a rock or mineral sample, prepared in a laboratory, for use with a polarizing petrographic microscope, electron microscope and electron microprobe. A thin sliver of rock is cut from the sample with a diamond saw and ... | Thin section |
c_l42czte8iimj | The method uses the Michel-Lévy interference colour chart to determine thickness, typically using quartz as the thickness gauge because it is one of the most abundant minerals. When placed between two polarizing filters set at right angles to each other, the optical properties of the minerals in the thin section alter ... | Thin section |
c_vpmmuotl7otm | Plagioclase for example can be seen in the photo on the right as a clear mineral with multiple parallel twinning planes. The large blue-green minerals are clinopyroxene with some exsolution of orthopyroxene. Thin sections are prepared in order to investigate the optical properties of the minerals in the rock. | Thin section |
c_ps2ioytszs6d | This work is a part of petrology and helps to reveal the origin and evolution of the parent rock. A photograph of a rock in thin section is often referred to as a photomicrograph. Thin sections are also used in the microscopic study of bones, metals and ceramics. | Thin section |
c_fj7z0r3pp4uf | In optical mineralogy, a petrographic microscope and cross-polarised light are often used to view the interference pattern. The thin section containing the mineral to be investigated is placed on the microscope stage, above one linear polariser, but with a second (the "analyser") between the objective lens and the eyep... | Optic sign |
c_qpq5p4nxvapu | This both maximises the solid angle subtended by the lens, and hence the angular variation of the light intercepted, and also increases the likelihood that only a single crystal will be viewed at any given time. To view the figure, the light rays leaving the microscope must emerge more or less in parallel. This is typi... | Optic sign |
c_szoh45en4nra | Any crystal section can in principle produce an interference pattern. However, in practice, only a few different crystallographic orientations are both 1. convenient to identify, to allow a figure to be produced, and 2. able to produce reliable information about crystal properties. Typically, the most useful and easily... | Optic sign |
c_trd1s5wn3kj3 | In optical mineralogy, an interference colour chart, also known as the Michel-Levy chart, is a tool first developed by Auguste Michel-Lévy to identify minerals in thin section using a petrographic microscope. With a known thickness of the thin section, minerals have specific and predictable colours in cross-polarized l... | Interference colour chart |
c_clqbepsrslz2 | In optical networking, a lightpath is a path between two nodes in an optical network between which light passes through unmodified. | Lightpath (optical network) |
c_my8x8kc34t6d | In optical physics, laser detuning is the tuning of a laser to a frequency that is slightly off from a quantum system's resonant frequency. When used as a noun, the laser detuning is the difference between the resonance frequency of the system and the laser's optical frequency (or wavelength). Lasers tuned to a frequen... | Laser detuning |
c_gvjb6dvdo1vf | In optical rectification, a high-intensity ultrashort laser pulse passes through a transparent crystal material that emits a terahertz pulse without any applied voltages. It is a nonlinear-optical process, where an appropriate crystal material is quickly electrically polarized at high optical intensities. This changing... | Terahertz time-domain spectroscopy |
c_0xdy4yfaoevw | Typical crystal materials are zinc telluride, gallium phosphide, and gallium selenide. The bandwidth of pulses generated by optical rectification is limited by the laser pulse duration, terahertz absorption in the crystal material, the thickness of the crystal, and a mismatch between the propagation speed of the laser ... | Terahertz time-domain spectroscopy |
c_6ui0ddyxbb2b | In optical sensor systems, problems occur due to the operation principle through the scattered light of the open arc. Therefore, measuring in the working point directly is in most cases not possible when optical sensors are used, a certain advance/distance must be maintained. Further process trouble stems from weld spa... | Sensors for arc welding |
c_adrdyueqsvrg | The direct observation of the arc with special cameras for process monitoring remain an exception. The running of the sensor in front of the arc causes the limited accessibility of corners in the parts. In order to reduce this problem, a design/structure which is as compact as possible and a short advance distance are ... | Sensors for arc welding |
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