Unreferenced date December 2009 The path that light takes in traversing an optical system is often called the optical path . The physical length of an optical device can be reduced to less than the length of the optical path by using folded optics . The optical path length as defined in optics is the length of the path multiplied by the index of refraction of the medium. See also Optical path length DEFAULTSORT Optical path Category Optics Optics stub de Strahlengang it Cammino ottico sv Str lg ng ... more details
Unreferenced date December 2009 Orphan date December 2009 A Tower telescope is a telescope with a large refraction length at which the tube is installed inside a tower. Tower telescopes are mainly used for examinations of the sun. Examples Solar Observatory Tower Meudon Richard B. Dunn Solar Telescope Mount Wilson Observatory Solar telescopes Mount Wilson Observatory DEFAULTSORT Tower Telescope Category Telescopes ... more details
Pseudomyopia refers to an intermittent and temporary shift in refraction of the eye towards myopia , in which the focusing of light in front of the retina is due to a transient spasm of the ciliary muscle causing an increase in the refractive power of the eye. It may be either organic, through stimulation of the parasympathetic nervous system , or functional in origin, through eye strain or fatigue of ocular systems. It is common in young adults who have active accommodation eye accommodation , and classically occurs after a change in visual requirements, such as students preparing for an exam, or a change in occupation. The major symptom is intermittent blurring of distance vision particularly noticeable after prolonged periods of near work, and symptoms of asthenopia . The vision may clear temporarily using concave minus lenses. The diagnosis is done by cycloplegia cycloplegic refraction using a strong cycloplegic like atropine or homatropine eye drops. Accommodative amplitude and facility may be reduced as a result of the ciliary muscle spasm. Treatment is dependent on the underlying aetiology. Organic causes may include systemic or ocular medications, brain stem injury, or active ocular inflammation such as uveitis . Functional pseudomyopia is managed though modification of working conditions, an updated refraction, or through appropriate ocular exercises. References Reflist cite journal author Chan R, Trobe J title Spasm of accommodation associated with closed head trauma. journal J Neuroophthalmol volume 22 issue 1 pages 15 7 year 2002 pmid 11937900 cite journal author Chentsova O, Shatalov O title Comparative analysis of the efficacy of some methods of conservative treatment of accommodation spasms and myopia in children journal Vestn Oftalmol volume 118 issue 6 pages 10 2 year 2002 pmid 12506647 See also Refraction Category Diseases of the eye and adnexa ... more details
orphan date January 2009 A ray of light traveling in an optical fiber must be incident at the critical angle on the internal surface of the fiber in order to have total internal reflection . When the ray is fed into the fiber, the refractive index of the traveling medium is different from what it is inside the optical fiber. So the angle of incidence should be such that after refraction, when the ray of light reaches the cladding, it does so at the critical angle. DEFAULTSORT Half Acceptance Angle Category Fiber optics Compu network stub ... more details
italictitle On Colors or De Coloribus is a treatise attributed to Aristotle but sometimes ascribed to Theophrastus or Strato of Lampsacus Strato . The work outlines the theory that all colors yellow, red, purple, green, and blue are derived from mixtures of black and white. On colors had a pronounced impact on subsequent color theories and remained influential until Isaac Newton s experiments with light refraction. See also Corpus Aristotelicum Philo stub Category Color Category Works by Aristotle is Um liti pt Das Cores fi V reist ... more details
The Pescadero Basin is a submarine depression located on the seabed at the southern end of the Gulf of California . The basin results from the activity of one of the several spreading centers in the Gulf. The basin is linked to the Pescadero Fault to the south, and the Atl Fault in the north. References http adsabs.harvard.edu abs 2003AGUFM.T31E0885S Continent Ocean Transition Across the Alarcon Basin, Gulf of California from Seismic Reflection and Refraction Data , Sutherland et al 2003 Category Geology of Mexico Category Article Feedback 5 ... more details
The Carmen Basin is a submarine depression geology depression located on the seabed at the southern end of the Gulf of California . The basin results from the activity of one of the several spreading centers in the Gulf. The basin is linked to the Farallon Fault to the south, and the Carmen Fault in the north. References http adsabs.harvard.edu abs 2003AGUFM.T31E0885S Continent Ocean Transition Across the Alarcon Basin, Gulf of California from Seismic Reflection and Refraction Data , Sutherland et al 2003 Category Geology of Mexico ... more details
A photometeor is a bright object or phenomenon appearing in Earth s atmosphere when sunlight or moonlight creates a reflection , refraction , diffraction or interference under particular circumstances. The most frequent are halo s, rainbow s, iridiscence s, glory optical phenomenon glories , Bishop s ring s, mirage s, scintillation s, green flash es, etc. See also Hydrometeor Lithometeor Electrometeor Notes and references references date April 2012 Portal Weather Category Meteorological phenomena Category Optical phenomena de Photometeor fr Photom t ore sv Meteor Fotometeorer climate stub ... more details
Unreferenced stub auto yes date December 2009 A transition radiation detector TRD is a particle detector using the math gamma math dependent threshold of transition radiation in a stratified material. It contains many layers of materials with different Index of refraction indices of refraction . At each interface between materials, the probability of transition radiation increases with the relativistic Lorentz factor gamma factor . Thus particles with large math gamma math give off many photons , and small math gamma math give off few. For a given energy, this allows a discrimination between a lighter particle which has a high math gamma math and therefore radiates and a heavier particle which has a low math gamma math and radiates much less . DEFAULTSORT Transition Radiation Detector Category Particle detectors Particle stub ar de bergangsstrahlungsdetektor ru ... more details
Refractor Engine is a game engine that was designed by Stockholm based studio Refraction Games , first developed for the video game Codename Eagle , which was released in November 1999. Refraction Games was later bought by Digital Illusions CE , and the engine was used in their flagship first person shooter title, Battlefield series Battlefield , specifically the first in the series Battlefield 1942 . DICE later designed and developed the Refractor 2 Engine to be used for the second installment of the sequel to Battlefield 1942 , Battlefield 2 . Games using Refractor Engine Version 1.0 Codename Eagle Battlefield 1942 Battlefield Vietnam Rallisport Challenge Version 2.0 Battlefield 2 Battlefield 2142 Battlefield Heroes Battlefield Online Battlefield Play4Free References Reflist Category Video game engines Videogame software stub ar da Refractor Engine hu Refractor Engine pl Refractor Engine pt Refractor Engine ru Refractor Engine tr Refractor Engine uk Refractor Engine zh Refractor ... more details
the light is bent when it enters the crystal angle of refraction . The index of refraction can be defined ... three indices of refraction na 1.485, nb 1.490, nc 1.494. A minerals birefringence is defined as the difference between the highest and lowest index of refraction, amicite s birefringence is 0.009 ... more details
ducts, the transmission can be extended to very large distances. Under refraction File Subrefraction.jpg thumb Under refraction in radar operation On the other hand, if the air is unstable and cools ... s causing irregularities in the troposphere , scattering due to meteor s, refraction in the ionized ... atmospheric ducting, ionospheric reflection and refraction, and reflection from water bodies and terrestrial ... factor for the propagation of radiowaves, especially the super refraction. However, reflection on the ionosphere ... observed when calm, stable atmospheric conditions, often associated with super refraction in a temperature ... more details
Snell s law also known as the Snell Descartes law and the law of refraction is a mathematical formula formula used to describe the relationship between the angle of incidence angles of incidence and refraction ... isotropic medium optics media , such as water and glass. Image Snells law2.svg thumb Refraction of light ... of refraction sub 2 sub is less than the angle of incidence sub 1 sub that is, the ray in the higher ... ray tracing to compute the angles of incidence or refraction, and in experimental optics and gemology ... index metamaterials , which allow light to be bent backward at a negative angle of refraction ... 355456 issue 3 ref Snell s law states that the ratio of the sine s of the angles of incidence and refraction ... to the opposite ratio of the indices of refraction math frac sin theta 1 sin theta 2 frac v 1 v ... showing his discovery of the law of refraction. Ptolemy , a Greek living in Alexandria , ref ... regarding refraction angles, but it was inaccurate for angles that were not small. Ptolemy was confident ... of Optics 1021 , came closer to discovering the law of refraction, though he did not take this step ... of refraction, lenses and rainbow , p. 5, Demokritus University, Thrace , Greece . ref Image Snell ..., 1837. ref The law of refraction was first accurately described by Ibn Sahl , of Baghdad , in the manuscript ... rays through refractive media with varying indices of refraction. The indices of refraction of the media ... would refract away from the normal line. Refraction between two surfaces is also referred to as reversible ... index of refraction , and proportionally lower speed of light , than the region above it. Snell s law .... Total internal reflection and critical angle File Refraction internal reflection diagram.svg thumb 250px right Demonstration of no refraction at angles greater than the critical angle. Main Total ... is large enough that the sine of the angle of refraction be greater than one. This of course is impossible ... and index of refraction are complex valued. Consequently, so are the angle of refraction ... more details
i.e. Royal London Refraction Hospital . ref Agarwal, R. 1985 , Royal LRH?, Optometry Today, volume ... three years later. Institute of Optometry In 1988 the London Refraction Hospital changed its name ... more details
of refraction versus molecular fraction of ethanol in water is linear, and the weight fraction equals ... structure that contributes to the net index of refraction. The refractivity of a single molecule is the refractive ... of refraction n is calculated from the change of angle of a collimated monochromatic beam of light from vacuum into liquid using Snell s law for refraction . Using the theory of light as an electromagnetic ... c , the index of refraction of water is n c v. The Gladstone Dale term n 1 is the non linear optical ... locally by electric forces acting between atoms, the optic path length is due to refraction at constant ... and measured average indices of refraction of minerals Mandarino 2007 . However, specific values ... model of light consistent with these electrostatic refraction calculations occurs if the electromagnetic ..., T.P. 1864 Researches on the refraction, dispersion and sensitiveness of liquids. Phil. Trans. Royal ..., 29, 525 32 Teertstra DK 2008a Photon refraction in dielectric crystals using a modified Gladstone Dale relation. J Phys Chem C 112, 7757 7760 Teertstra DK 2008b The refraction of light by garnet ... more details
The rippability of an earth rock material is a measure of its ability to be excavated with conventional excavation equipment. ref cite book author W. Ed Wightman, Frank Jalinoos, Philip Sirles, and Kanaan Hanna title Application of Geophysical Methods to Highway Related Problems year 2003 chapter 6.2.3 Determining the Rippability of Rocks pages 318 322 publisher Federal Highway Administration, Central Federal Lands Highway Div. url http www.cflhd.gov agm engapplications SubsurfaceChartacter 623DeterminingRippabilityRock.htm accessed 17 Sep 2009 ref A material may be classified as rippable, marginally rippable or non rippable. The rippability of a material is often evaluated by an engineering geologist and or geophysicist utilizing the seismic refraction equipment see refraction ,. ref cite journal author F. MacGregor, R. Fell, G. R. Mostyn, G. Hocking, and G. McNally title The estimation of rock rippability journal Quarterly Journal of Engineering Geology & Hydrogeology year 1994 volume 27 issue 2 pages 123 144 doi 10.1144 GSL.QJEGH.1994.027.P2.04 ref ref cite journal author D. M. McCann and P.J. Fenning title Estimation of rippability and excavation conditions from seismic velocity measurements journal Geological Society, London, Engineering Geology Special Publications year 1995 volume 10 pages 335 343 doi 10.1144 GSL.ENG.1995.010.01.29 ref Rippability studies can involve the performance of seismic refraction traverse s, the drilling of boring s with an air percussion drill rig, the excavation of test trenches with a bulldozer with rippers or backhoe, and by geologic mapping. References Reflist Category Geotechnical engineering civil engineering stub ... more details
In nonlinear optics , filament propagation is propagation of a beam of light through a medium without diffraction . This is possible because the Kerr effect causes an index of refraction change in the medium, resulting in self focusing of the beam. Filament propagation of laser pulses in the atmosphere was observed in 1994 by G rard Mourou and his team at University of Michigan . The balance between the self focusing refraction and self attenuating diffraction by ionization and rarefaction of a laser beam of terawatt intensities, created by chirped pulse amplification , in the atmosphere creates filaments which act as waveguides for the beam thus preventing divergence. If a light filament drops below the intensity needed for this dynamic balance, called modulation instability, it can merge with another filament and continue propagating without broadening as with all earlier means of sending light. The filaments, having made a plasma, turn the narrowband laser pulse into a broadband pulse having a wholly new set of applications. Filament propagation in a semiconductor medium can also be observed in large aperture vertical cavity surface emitting laser s. External links http www.aip.org pt vol 54 iss 8 p17.html Experiments Detail How Powerful Ultrashort Laser Pulses Propagate through Air http www.nrl.navy.mil content.php?P 03REVIEW59 Filamentation and Propagation of Ultra Short, Intense Laser Pulses in Air optics stub Category Nonlinear optics ... more details
Unreferenced date December 2009 About the album by the experimental music group Urdu band Urdu the Indo Aryan language Urdu Infobox Album See Wikipedia WikiProject Albums Name Urdu Type studio Longtype Artist Urdu band Urdu Cover Released 1985 Recorded Genre Art rock Length 52 08 Label Refraction record company Refraction Producer Reviews Last album This album Next album Urdu 1985 is the only album released by the Art rock experimental pop music group Urdu band Urdu . Urdu was a trio consisting of Robert Rich musician Robert Rich , Rick Davies musician Rick Davies and Andrew McGowan. They worked together under this name from 1983 84. This album of their accumulated recordings was released in 1985, after Urdu s members had moved on to other projects. Track listing Questioning the Moon 6 07 Jazz Rmff 4 07 Air Ritual 5 50 Land s End 7 40 To the Menlo Walker 9 14 Billboard Angel 5 30 Amphibian 10 40 DEFAULTSORT Urdu Album Category Urdu albums Category 1985 albums ... more details
Multiple issues refimprove June 2010 orphan December 2007 wikify December 2010 The plus minus method is a geophysical principle attributed to Hagedoorn for statics solution derivation in which two emergence points on a refractor and a common midpoint cmp on the surface are considered. It is used to interpret seismic refraction profiles over irregular layers whose slope angles are less that 10 . Both forward and reverse shooting allow for matched time distance graphs to be plotted. The Plus component of the method allows for the perpendicular depth to the refractor to be calculated. The Minus component helps determine the seismic velocity of the refractive medium. Examples t tABCD tDEFG tABFG t tABCD tDEFG tABFG see the figure in the Seismic Data Processing text by Ozdogan Yilmaz on pg 227 References reflist Further reading http www.cseg.ca publications journal 1965 12 1965 Hagedoorn J plus minus method.pdf The Plus Minus Method of Interpreting Seismic Refraction Sections authored by J.G. Hagedoorn presented to the fifteenth meeting of the European Association of Exploration Geophysicists in London from 10 to 12 December 1958 . Published in Geophysical Prospecting, the Plus minus method is elaborated on pg. 67 Category Seismology measurement Geophysics stub ... more details
RadExPro is a Windows based seismic processing software system produced by DECO Geophysical Software Company. It is suitable for processing of near surface seismics, including seismic reflection , seismic refraction refraction , and MASW. It is also suitable for field seismic acquisition QC, as well as for Vertical seismic profile VSP data processing ref http paulsson.com vsp and 2D seismic software.html ref . The RadExPro software took its origin in 1992 at Moscow State University Lomonosov Moscow State University , Faculty of Geology and later on was transferred to the company together with its initial authors. Originally having been actively sold in Russia and former Soviet Union countries, since 2004 the RadExPro is internationally available. In 2010 the company claimed that they sold more than 400 licenses world wide ref http radexpro.com company our clients ref . References See http en.wikipedia.org wiki Wikipedia Footnotes on how to create references using ref ref tags which will then appear here automatically Reflist External links http www.radexpro.com Official web site of the RadExPro seismic software Categories Category Seismology measurement Category Geophysics Category Geology software ... more details
PLEASE READ Wikipedia Disambiguation dos and don ts BEFORE EDITING NPV can refer to Net present value , an economic standard method for evaluating competing long term projects in capital budgeting Negative predictive value , in biostatistics, the proportion of patients with negative test results who are correctly diagnosed Nuclear Polyhedrosis Virus , a virus that infects butterflies and moths Negative refraction Negative Phase Velocity , an electromagnetic property induced by some exotic optical materials National Popular Vote Interstate Compact , an initiative to circumvent the current U.S. Electoral College system and elect the candidate with the most votes nationwide De Nederlandse Padvinders Netherlands Pathfinders , a precursor to Scouting Nederland , the national scouting organisation of the Netherlands disambig de NPV fr NPV it NPV nl NPV ja NPV ... more details
The abbreviation DPT can refer to The Democratic Party of Turkmenistan The DPT vaccine Diphtheria Pertussis Tetanus vaccine The Democratic peace theory Democratic Peace Theory Dioptre , most commonly a unit measuring refraction in a lens or curved mirror Dipropyltryptamine , a psychedelic tryptamine Doctor of Physical Therapy degree Double permutation test , in statistics Pok mon Diamond and Pearl Pok mon Diamond, Pearl and Pok mon Platinum Platinum DPt , a trilogy of video game s for the Nintendo DS Dirty Pretty Things band , a band founded in 2005 Dirty Pretty Things film , a movie released in 2002 Dynamic Packet Transport Dynamic Preemption Threshold scheduling algorithm Dublin Port Tunnel Dual Port Transceiver , a computer networking device Dumbarton People s Theatre disambig de DPT fa DPT it DPT ja DPT ... more details
The abbreviation IOR may refer to Institute of Recruiters , a non profit Institute for recruiters and HR professionals Refractive index Index of refraction Istituto per le Opere di Religione Institute for Religious Works , the Vatican Bank Interoperable Object Reference , a reference to a CORBA or RMI IIOP object Inhibition of return , a phenomenon in visual perception International Offshore Rule , an early handicapping system for yacht racing Independent Order of Rechabites inclusive or as opposed to XOR exclusive OR IORgroup Ltd formerly Interiors of Richmond , a London based commercial interior design company I.O.R. , optics company of Romania Interest on Reserves, a term used in macroeconomics having to do with the Federal Reserve System disambig de IOR it IOR ja IOR pl IOR ... more details
Unreferenced stub auto yes date December 2009 Tauno Johannes Kukkam ki 1909 1997 was a Finland Finnish geodesist renowned especially for his research into levelling refraction . He defended his doctoral thesis in University of Turku in 1933 on the metrology of length by means of the Yrj V is l V is l comparator. He served as the Director of the Finnish Geodetic Institute 1963 1977. Persondata Metadata see Wikipedia Persondata . NAME Kukkamaki, Tj ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH 1909 PLACE OF BIRTH DATE OF DEATH 1997 PLACE OF DEATH DEFAULTSORT Kukkamaki, Tj Category 1909 births Category 1997 deaths Category Finnish geodesists Finland scientist stub it Tauno Kukkam ki fi T. J. Kukkam ki ... more details
Orphan date December 2009 Unreferenced stub auto yes date December 2009 The Neelanjali Ruby , at 1,370 Carat unit carats 274 g , is the world s largest double star ruby . A ruby is known as a star ruby if it contains an asterism gemmology asterism distinctive star shaped light refraction in the gem. The Neelanjali Ruby is the world s largest star ruby with a 12 point asterism, which is commonly denoted as a double star ruby. The ruby belongs to G. Vidyaraj and is reported to be in Bangalore , India . Category Named rubies Mineral stub ... more details
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