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	Ultraviolet divergence - Biocrawler
		In physics, an ultraviolet divergence is a situation in which an integral, for example a Feynman diagram, diverges because of contributions of objects with very high energy approaching infinity, or, equivalently, because of physical phenomena at very short distances.
		The classic example of an ultraviolet divergence, and the scenario from which the name arises, occurs when one attempts to calculate the amount of radiation emitted by a fl body using classical mechanics.
		This problem, which was known as the ultraviolet catastrophe, is addressed by quantum mechanics, which limits the amount of radiation emitted at low wavelengths by requiring that low-wavelength light exist in larger energy packets.
	www.biocrawler.com /encyclopedia/Ultraviolet_divergence (209 words)

	Nikon MicroscopyU: Laser Safety
		Ultraviolet-A (315-400 nanometers): The cornea and aqueous humor transmit this wavelength range, which is then primarily absorbed by the lens of the eye.
		In general, ultraviolet and far-infrared laser radiation is absorbed at the cornea or lens, and its effect depends upon the intensity and exposure duration.
		Very little of the ultraviolet 325-nanometer radiation is able to reach the retina due to strong absorption by the eye lens, and long-term exposure may contribute to cataract development.
	www.microscopyu.com /articles/fluorescence/lasersafety.html (7418 words)

	NationMaster - Encyclopedia: Ultraviolet divergence
		The solution to this problem, which was known as the ultraviolet catastrophe, is quantum mechanics which limits the amount of radiation emitted at low wavelengths by requiring that low wavelength light exist in larger energy packets.
		The ultraviolet catastrophe, also called the Rayleigh-Jeans catastrophe, was a prediction of early 20th century classical physics that an ideal fl body at thermal equilibrium will emit radiation with infinite power.
		The term "ultraviolet catastrophe" was first used in 1911 by Paul Ehrenfest, although the concept goes back to 1905; the word "ultraviolet" refers to the fact that the problem appears in the short wavelength region of the electromagnetic spectrum.
	www.nationmaster.com /encyclopedia/Ultraviolet-divergence (453 words)

	Olympus Microscopy Resource Center: Light and Color - Electromagnetic Radiation
		Ultraviolet radiation, at the other end of the visible spectrum, was discovered by Wilhelm Ritter, who was one of the first scientists to investigate the energy associated with visible light.
		Photon energies in the ultraviolet are sufficient to ionize the atoms from a number of gas molecules in the atmosphere, and this is the process by which the ionosphere is created and sustained.
		Ultraviolet light is utilized extensively in scientific instruments to probe the properties of various chemical and biological systems, and it is also important in astronomical observations of the solar system, galaxy, and other parts of the universe.
	www.olympusmicro.com /primer/lightandcolor/electromagintro.html (4927 words)

	Ultraviolet catastrophe - Wikipedia, the free encyclopedia
		The ultraviolet catastrophe, also called the Rayleigh-Jeans catastrophe, was a prediction of early 20th century classical physics that an ideal fl body at thermal equilibrium will emit radiation with infinite power.
		The term "ultraviolet catastrophe" was first used in 1911 by Paul Ehrenfest, although the concept goes back to 1905; the word "ultraviolet" refers to the fact that the problem appears in the short wavelength region of the electromagnetic spectrum.
		The ultraviolet catastrophe results from the equipartition theorem of classical statistical mechanics which states that all modes (degrees of freedom) of a system at equilibrium have an average energy of kT / 2.
	en.wikipedia.org /wiki/Ultraviolet_catastrophe (584 words)

	Ultraviolet divergence - Wikipedia, the free encyclopedia
		In physics, an ultraviolet divergence is a situation in which an integral, for example a Feynman diagram, diverges because of contributions of objects with very high energy approaching infinity, or, equivalently, because of physical phenomena at very short distances.
		The ultraviolet (UV) divergences are often unphysical effects that can be removed by regularization and renormalization.
		This problem, which was known as the ultraviolet catastrophe, is addressed by quantum mechanics, which limits the amount of radiation emitted at low wavelengths by requiring that low-wavelength light exist in larger energy packets.
	en.wikipedia.org /wiki/Ultraviolet_divergence (209 words)

	Infrared divergence - Biocrawler
		In physics, an infrared divergence is a situation in which an integral, for example a Feynman diagram, diverges because of contributions of objects with very small energy approaching zero, or, equivalently, because of physical phenomena at very long distances.
		The infrared (IR) divergence usually appears in theories with massless particles, and it means that we have asked an incorrect question.
		See also ultraviolet divergence, cutoff, renormalization, renormalization group.
	www.biocrawler.com /encyclopedia/Infrared_divergence (118 words)

	Search Encyclopedia.com (Site not responding. Last check: )
		Ozone in the ozone layer is formed by the action of solar ultraviolet light on oxygen.
		Essential in regulating calcium and phosphorus absorption by the body, vitamin D can be formed in the skin by ultraviolet rays contained in sunlight; it can also be consumed in such foods as fish oils, eggs, and butter.
		Acquired mutations are caused by repeated insults from triggers (e.g., cigarette smoke or ultraviolet rays) referred to as carcinogens.
	www.encyclopedia.com /search.asp?target=Ultraviolet+divergence&rc=10&fh=12&fr=11 (518 words)

	Laser Fundamentals
		Ultraviolet radiation for lasers consists of wavelengths between 180 and 400 nm.
		When radiation is absorbed, the effect on the absorbing biological tissue is either photochemical, thermal, or mechanical: in the ultraviolet region, the action is primarily photochemical; in the infrared region, the action is primarily thermal; and in the visible region, both effects are present.
		The shorter wavelengths are the ultraviolet and the longer wavelengths are the infrared.
	www.fas.org /man/dod-101/navy/docs/laser/fundamentals.htm (2259 words)

	Ultraviolet catastrophe -- Facts, Info, and Encyclopedia article (Site not responding. Last check: )
		The solution to this problem led to the development of an early form of (The branch of quantum physics that accounts for matter at the atomic level; an extension of statistical mechanics based on quantum theory (especially the Pauli exclusion principle)) quantum mechanics.
		According to classical electromagnetism, the number of electromagnetic modes in a 3-dimensional cavity, per unit frequency, is proportional to the square of the frequency.
		The packets of energy later came to be called (A quantum of electromagnetic radiation; an elementary particle that is its own antiparticle) photons, and played a key role in the quantum description of electromagnetism.
	www.absoluteastronomy.com /encyclopedia/u/ul/ultraviolet_catastrophe.htm (536 words)

	[No title]
		In figure 2, the high intensity of the ultraviolet emission, the richness of the lines, and their fairly even distribution over the entire spectral range, freedom from wandering, and the localization of the luminous area in a small region may be seen.
		Apomorphine ultraviolet spectra obtained by different Hilger instruments were shown to have fine structure between 300 and 325 mμ as found by Gompel and Henri (1912), and Elvidge (1940) ([39]).
		The ultraviolet chromophore present in N-allylnormorphine, morphine, normorphine, and related compounds, is the hexadrophenanthrene ring, according to Seagers et al., to which chromophore the authors attribute the similarity of the ultraviolet spectra of all opiates ([54]).
	www.unodc.org /unodc/bulletin/bulletin_1954-01-01_3_page005.html?print=yes (12178 words)

	Atmospheric thermodynamics 2
		About 10% of the radiation is in the near end of the ultraviolet range (0.1 to 0.4 microns), 40% in the visible light range (0.4 to 0.7 µm), 49% in the short wave infra-red range (0.7 to 3.0 µm) and 1% is higher energy and X-ray radiation.
		As the surface pressure is the weight per unit area of the overlaying column of air, and even though divergences in one part of the column are largely balanced by convergences in another, the slight change in mass content (thickness) of the over-riding air changes the pressure at the surface.
		Divergence or convergence may be induced by a change in surface drag, for instance when an airstream crosses a coastline.
	www.auf.asn.au /meteorology/section1b.html (5003 words)

	LEOT Laser Tutorial - Course 3: Laser Technology - Module 13: Measurement of Laser Outputs (Site not responding. Last check: )
		The far-field beam divergence of a laser is the constant beam divergence angle at a large distance from the laser output aperture.
		The beam divergence may be determined by measuring the beam diameter at the focal point of a positive lens and then calculating the divergence angle.
		A laser with a divergence angle of 1.0 mrad and output power of 0.68 W is focused onto an aperture with a diameter of 1.0 mm by a lens with a focal length of 120 cm.
	repairfaq.ece.drexel.edu /sam/CORD/leot/course03_mod13/mod03-13.html (5297 words)

	Burning lasers from megalaser
		The most powerful ultraviolet laser in the world, (the 60-terawatt Omega, at the Laboratory for Laser Energetics at the University of Rochester, New York) is used to test fusion experiments (the same nuclear energy that powers the sun).
		Laser radiation may be emitted in the visible portion of the electromagnetic spectrum, wavelengths of 0.4 µ m and 0.7 µ m, or in the invisible infrared and ultraviolet regions.
		At longer and shorter wavelengths, such as the far infrared and the ultraviolet, radiation striking the eye is absorbed in the cornea and the lens rather than being focused on the retina.
	www.megalaser.com /lasers.htm (1686 words)

	Ultraviolet
		Ultraviolet (UV) radiation is electromagnetic radiation of a wavelength shorter than that of the visible region, but longer than that of soft X-rays.
		Many birds have patterns in their plumage that are invisible at usual wavelengths but seen in ultraviolet, and the urine of some animals is much easier to spot with ultraviolet.
		solar corona as seen in "deep" ultraviolet light at 17.1 nm by the Extreme ultraviolet Imaging Telescope instrument aboard the SOHO spacecraft]] The Sun emits ultraviolet radiation in the UVA, UVB, and UVC bands, but because of absorption in the atmosphere's ozone layer, 99% of the ultraviolet radiation that reaches the Earth's surface is UVA.
	www.kiwipedia.com /en/ultraviolet.html (445 words)

	Broadmining: Ultraviolet (Site not responding. Last check: )
		Ultraviolet radiation itself is invisible, but illuminating certain materials with UV radiation prompts the visible effects of fluorescence and
		Ultraviolet lamps are used to sterilize workspaces and tools used in biology laboratories and medical facilities.
		Ultraviolet radiation is increasingly being used to disinfect drinking water and in waste water treatment plants.
	lowide.com /Ultraviolet (1953 words)

	12.20.2001 - World's smallest laser caught in act of lasing by UC Berkeley chemists
		Because the diameter of the wire is less than a full wavelength, the beam diverges at a large angle upon exiting the nanowire, forming a cone.
		These ultraviolet nanolasers have generated great excitement in the optoelectronics community because of their potential applications in miniature optical computer circuitry and communications devices, Yang said.
		By measuring the patterns of the emitted laser light, the chemists were able to determine the mechanism of the laser action and the optical properties of the nanolaser.
	www.berkeley.edu /news/media/releases/2001/12/20_laser.html (606 words)

	Laser diode/lens assembly - Patent 5615052
		Furthermore, the divergence or focus of one particular laser diode/lens assembly may be different than the divergence or focus of another laser diode/lens assembly, depending on the mechanical tolerances of the various parts making up the two different assemblies.
		The divergence or focus must, however, remain substantially constant during operation of the gas spectroscopy device due to the spatial variation in sensitivity of photodetectors as well as the spatial sensitivity of the beam directing properties of the sample cell containing the gas being analyzed.
		Because the lens is immovably fixed directly to the housing of the laser diode, the divergence or focus of the laser beam, while not precisely known, varies less than does the divergence or focus of a beam typically emitted from a laser diode collimator of the prior art.
	www.freepatentsonline.com /5615052.html (8110 words)

	LED infrared skin rejuvination light anti-aging, wounds acne DPL Therapy as seen on TV informercials NASA Infra-Red
		Red or ultraviolet light was successfully used in the 19th century for the treatment of pockmarks and lupus vulgaris by Danish physician, N. Finsen, the father of contemporary phototherapy.
		However, ultraviolet light is an ionizing radiation, and therefore has a damaging potential for biomolecules and has to be used in photomedicine with certain precautions.
		The beam diameter and divergence should be selected based on the three dimensional size and shape of the tissue area affected.
	www.lighttherapyproducts.com /LEDMorestudies.html (2333 words)

	Untitled Document
		This is because of a property called "divergence." Think of a flashlight, whose light beam spreads out as you move farther away from it.
		This divergence or spreading out of the beam means that the power of the light is spread over an in- creasingly larger area as you move farther away.
		When the light from a light bulb is reflected off a mirror, it continues to diverge and spread its energy over even larger areas.
	vm.cfsan.fda.gov /~cjm/rh/laser1bg.html (1027 words)

	Ultraviolet Divergence
		However I think the ultraviolet divergence is more = = fundamental problem that that solved by renormalization.
		The divergence is cancelled by counter terms in the bare coupling constant which is itself assumed divergent.
		Ultraviolet divegence is very old problem and is not solved completely yet.
	www.pych-one.com /new-5352011-4395.html (1189 words)

	How gas-ion lasers work
		This fundamental mode results in the smallest beam diameter and beam divergence and is capable of being focused to the smallest possible spot size.
		The beam divergence is usually given as the full angle divergence measured in the far field.
		Diameter and divergence values for selected ion laser wavelengths are available for the Lexel 85/95 series, the Lexel 85-SHG and for the Lexel 95-SHG.
	www.lexellaser.com /techinfo_gas-ion.htm (1503 words)

	Read about Ultraviolet divergence at WorldVillage Encyclopedia. Research Ultraviolet divergence and learn about ... (Site not responding. Last check: )
		In physics, an ultraviolet divergence is a situation in which an
		integral, for example a Feynman diagram, diverges because of contributions of objects with very high energy approaching infinity, or, equivalently, because of physical phenomena at very short distances.
		The classic example of an ultraviolet divergence, and the scenario from which the name arises, occurs when one attempts to calculate the amount of radiation emitted by a
	encyclopedia.worldvillage.com /s/b/Ultraviolet_divergence (207 words)

	Re: Volume in the event horizon?
		As particle theory jargon would put it, this is an "infrared divergence" that comes from assuming infinitely large boundary conditions, not an "ultraviolet divergence" that comes from assuming local pointwise interactions.
		Usually infrared divergences are thought of as artifacts of idealization or calculational techniques, not inherently very interesting, whereas ultraviolet divergences are thought of as signs of the limits of a theory at modeling reality on small or high-energy scales.
		Then both kinds of divergence are just indications that you need to fill the regions you don't care about modeling with some sort of calculational placeholder, chosen for convenience-- what we call a regulator.
	www.lns.cornell.edu /spr/1999-06/msg0016969.html (372 words)

	University of Wisconsin - Madison - Zoology Department
		While the underlying mechanism responsible for this phenomenon remains unclear (though evidence suggests that it has a physiological basis independent of body mass), this novel result challenges the view that molecular markers are insensitive to environmental effects.
		To investigate this hypothesis further, I undertook studies of the fossil record to test the validity of divergence times based on assumptions of a molecular clock; such dates are often much older than those indicated by the evidentiary fossil record.
		With hummingbirds, I was then able to develop this idea further to suggest that sexual dimorphism reflects priority of access to food resources as determined by the combined influences of social dominance and of constraints imposed on dominance by mating system.
	www.zoology.wisc.edu /faculty/Ble/Ble.html (1470 words)

	2.2 Divergences in quantum gravity
		In general, the loop momentum integrals in a quantum field theory will diverge in the ultraviolet where the momenta in the loops become arbitrarily large.
		Unless these divergences are of the right form they indicate that a theory cannot be interpreted as fundamental, but is instead valid only at low energies.
		Explicit calculations have shown that non-supersymmetric theories of gravity with matter generically diverge at one loop [132, 43, 42], and pure gravity diverges at two loops [66, 136].
	relativity.livingreviews.org /Articles/lrr-2002-5/node4.html (717 words)

	ANIMAL BEHAVIOR: ON BAT ECHOLOCATION
		Ultraviolet vision was discovered in mammals only a decade ago(2), and in the few rodents and marsupials where it has been found, ultraviolet light is detected by an independent photoreceptor(2,3).
		The authors suggest the result proves that these bats are capable of ultraviolet perception through a single receptor mechanism not previously demonstrated in mammals with intact eyes.
		Chromatic adaptation had the same threshold-elevating effects on ultraviolet and visible test lights, indicating that the same photoreceptor is responsible for both response peaks (ultraviolet and green).
	scienceweek.com /2004/sa040827-1.htm (1307 words)

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