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Dispersion Staining
The optical properties of all liquid and solid materials change as a function of the wavelength of light used to measure them. This change as a function of wavelength is called the dispersion of the optical properties. The graph created by plotting the optical property of interest by the wavelength at which it is measured is called a dispersion curve. The dispersion staining is an analytical technique used in light microscopy that takes advantage of the differences in the dispersion curve of the refractive index of an unknown material relative to a standard material with a known dispersion curve to identify or characterize that unknown material. These differences become manifest as a color when the two dispersion curves intersect for some visible wavelength. This is an optical staining technique and requires no stains or dyes to produce the color. Its primary use today is in the confirmation of the presence of asbestos in construction materials but it has many other applications ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrocellulose
Nitrocellulose (also known as cellulose nitrate, flash paper, flash cotton, guncotton, pyroxylin and flash string, depending on form) is a highly flammable compound formed by nitrating cellulose through exposure to a mixture of nitric acid and sulfuric acid. One of its first major uses was as guncotton, a replacement for gunpowder as propellant in firearms. It was also used to replace gunpowder as a low-order explosive in mining and other applications. In the form of collodion it was also a critical component in an early photographic emulsion, the use of which revolutionized photography in the 1860s. Production The process uses a mixture of nitric acid and sulfuric acid to convert cellulose into nitrocellulose. The quality of the cellulose is important. Hemicellulose, lignin, pentosans, and mineral salts give inferior nitrocelluloses. In precise chemical terms, nitrocellulose is not a nitro compound, but a nitrate ester. The glucose repeat unit (anhydroglucose) within the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Köhler Illumination
Köhler illumination is a method of specimen illumination used for transmitted and reflected light (trans- and epi-illuminated) optical microscopy. Köhler illumination acts to generate an even illumination of the sample and ensures that an image of the illumination source (for example a halogen lamp filament) is not visible in the resulting image. Köhler illumination is the predominant technique for sample illumination in modern scientific light microscopy. It requires additional optical elements which are more expensive and may not be present in more basic light microscopes. History and motivation Prior to Köhler illumination critical illumination was the predominant technique for sample illumination. Critical illumination has the major limitation that the image of the light source (typically a light bulb) falls in the same plane as the image of the specimen, i.e. the bulb filament is visible in the final image. The image of the light source is often referred to as the filame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion Staining Becke Line
Dispersion may refer to: Economics and finance * Dispersion (finance), a measure for the statistical distribution of portfolio returns *Price dispersion, a variation in prices across sellers of the same item * Wage dispersion, the amount of variation in wages encountered in an economy * Dispersed knowledge, notion that any one person is unable to perceive all economic forces Science and mathematics Mathematics * Statistical dispersion, a quantifiable variation of measurements of differing members of a population **Index of dispersion, a normalized measure of the dispersion of a probability distribution * Dispersion point, a point in a topological space the removal of which leaves the space highly disconnected Physics *The dependence of wave velocity on frequency or wavelength: **Dispersion (optics), for light waves ** Dispersion (water waves), for water waves ** Acoustic dispersion, for sound waves ** Dispersion relation, the mathematical description of dispersion in a system ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion Staining Color Pairs2
Dispersion may refer to: Economics and finance * Dispersion (finance), a measure for the statistical distribution of portfolio returns *Price dispersion, a variation in prices across sellers of the same item * Wage dispersion, the amount of variation in wages encountered in an economy * Dispersed knowledge, notion that any one person is unable to perceive all economic forces Science and mathematics Mathematics * Statistical dispersion, a quantifiable variation of measurements of differing members of a population **Index of dispersion, a normalized measure of the dispersion of a probability distribution * Dispersion point, a point in a topological space the removal of which leaves the space highly disconnected Physics *The dependence of wave velocity on frequency or wavelength: **Dispersion (optics), for light waves ** Dispersion (water waves), for water waves ** Acoustic dispersion, for sound waves ** Dispersion relation, the mathematical description of dispersion in a system ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion Staining Darkfield
Dispersion may refer to: Economics and finance * Dispersion (finance), a measure for the statistical distribution of portfolio returns *Price dispersion, a variation in prices across sellers of the same item * Wage dispersion, the amount of variation in wages encountered in an economy * Dispersed knowledge, notion that any one person is unable to perceive all economic forces Science and mathematics Mathematics * Statistical dispersion, a quantifiable variation of measurements of differing members of a population **Index of dispersion, a normalized measure of the dispersion of a probability distribution * Dispersion point, a point in a topological space the removal of which leaves the space highly disconnected Physics *The dependence of wave velocity on frequency or wavelength: **Dispersion (optics), for light waves ** Dispersion (water waves), for water waves ** Acoustic dispersion, for sound waves ** Dispersion relation, the mathematical description of dispersion in a system ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion Staining Color Pairs
Dispersion may refer to: Economics and finance * Dispersion (finance), a measure for the statistical distribution of portfolio returns *Price dispersion, a variation in prices across sellers of the same item * Wage dispersion, the amount of variation in wages encountered in an economy * Dispersed knowledge, notion that any one person is unable to perceive all economic forces Science and mathematics Mathematics * Statistical dispersion, a quantifiable variation of measurements of differing members of a population **Index of dispersion, a normalized measure of the dispersion of a probability distribution * Dispersion point, a point in a topological space the removal of which leaves the space highly disconnected Physics *The dependence of wave velocity on frequency or wavelength: **Dispersion (optics), for light waves ** Dispersion (water waves), for water waves ** Acoustic dispersion, for sound waves ** Dispersion relation, the mathematical description of dispersion in a system ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dispersion Staining Phase Contrast
Dispersion may refer to: Economics and finance * Dispersion (finance), a measure for the statistical distribution of portfolio returns *Price dispersion, a variation in prices across sellers of the same item * Wage dispersion, the amount of variation in wages encountered in an economy * Dispersed knowledge, notion that any one person is unable to perceive all economic forces Science and mathematics Mathematics * Statistical dispersion, a quantifiable variation of measurements of differing members of a population **Index of dispersion, a normalized measure of the dispersion of a probability distribution * Dispersion point, a point in a topological space the removal of which leaves the space highly disconnected Physics *The dependence of wave velocity on frequency or wavelength: **Dispersion (optics), for light waves ** Dispersion (water waves), for water waves ** Acoustic dispersion, for sound waves ** Dispersion relation, the mathematical description of dispersion in a system ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isaac Newton
Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a "natural philosopher"), widely recognised as one of the greatest mathematicians and physicists and among the most influential scientists of all time. He was a key figure in the philosophical revolution known as the Enlightenment. His book (''Mathematical Principles of Natural Philosophy''), first published in 1687, established classical mechanics. Newton also made seminal contributions to optics, and shares credit with German mathematician Gottfried Wilhelm Leibniz for developing infinitesimal calculus. In the , Newton formulated the laws of motion and universal gravitation that formed the dominant scientific viewpoint for centuries until it was superseded by the theory of relativity. Newton used his mathematical description of gravity to derive Kepler's laws of planetary motion, account for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractive Index
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or refracted, when entering a material. This is described by Snell's law of refraction, , where ''θ''1 and ''θ''2 are the angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices ''n''1 and ''n''2. The refractive indices also determine the amount of light that is reflected when reaching the interface, as well as the critical angle for total internal reflection, their intensity ( Fresnel's equations) and Brewster's angle. The refractive index can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is , and similarly the wavelength in that medium is , where ''Π... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Christiansen (physicist)
Christian Christiansen (9 October 1843 in Lønborg, Denmark – 28 November 1917 Frederiksberg) was a Danish physicist. Christiansen first taught at the local polytechnical school. In 1886, he was appointed to a chair for physics at the University of Copenhagen. He mainly studied radiant heat and optical dispersion, discovering the Christiansen effect (Christiansen filter). Around 1917, he discovered the anomalous dispersion of numerous dyes, including aniline red (fuchsine), by recording absorption spectra. In 1884, he confirmed the Stefan–Boltzmann law. Christiansen was elected a member of the Royal Swedish Academy of Sciences in 1902. He was doctoral advisor to Niels Bohr. In 1912, he retired and Martin Knudsen Martin Hans Christian Knudsen (February 15, 1871 in Hasmark on Funen – May 27, 1949 in Copenhagen) was a Danish physicist who taught and conducted research at the Technical University of Denmark. He is primarily known for his study of molecu ... became ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christiansen Filter
The Christiansen effect is named after the Danish physicist Christian Christiansen and describes the reduced scattering of multi-phase microstructures at wavelengths where their refractive indices match. A Christiansen filter is a narrow bandpass or monochromatic optical filter which consists of an optical cell which is stuffed with a crushed substance (e.g. glass) and a (mostly organic) liquid. The liquid is chosen according to the substance, so that the dispersion curves coincide at one wavelength. For this wavelength the filled optical cell behaves like a plane-parallel, homogeneous disk and allows transmission. All other wavelength ranges of the spectrum are reflected, scattered as well as refracted at the many interfaces between substance and liquid. A change of the transmission behavior of this dispersion filter can be achieved by variation of the liquid, the temperature or variation of the pressure. The fundamental consequence is the change of the refractive index of the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monochromatic Light
{{Short description, Electromagnetic radiation with a single constant frequency In physics, monochromatic radiation is electromagnetic radiation with a single constant frequency. When that frequency is part of the visible spectrum (or near it) the term monochromatic light is often used. Monochromatic light is perceived by the human eye as a spectral color. When monochromatic radiation propagates through vacuum or a homogeneous transparent medium, it has a single constant wavelength. Practical monochromaticity No radiation can be totally monochromatic, since that would require a wave of infinite duration as a consequence of the Fourier transform's localization property (cf. spectral coherence). In practice, "monochromatic" radiation — even from lasers or spectral lines — always consists of components with a range of frequencies of non-zero width. Generation Monochromatic radiation can be produced by a number of methods. Isaac Newton observed that a beam of light from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
