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Spectrophotometry
Spectrophotometry is a branch of electromagnetic spectroscopy concerned with the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. Spectrophotometry uses photometers, known as spectrophotometers, that can measure the intensity of a light beam at different wavelengths. Although spectrophotometry is most commonly applied to ultraviolet, Visible spectrum, visible, and infrared radiation, modern spectrophotometers can interrogate wide swaths of the electromagnetic spectrum, including x-ray, ultraviolet, Visible spectrum, visible, infrared, or microwave wavelengths. Overview Spectrophotometry is a tool that hinges on the quantitative analysis of molecules depending on how much light is absorbed by colored compounds. Important features of spectrophotometers are spectral bandwidth (the range of colors it can transmit through the test sample), the percentage of sample transmission, the logarithmic range of sample absorptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy (astronomy)
Astronomical spectroscopy is the study of astronomy using the techniques of spectroscopy to measure the spectrum of electromagnetic radiation, including visible light, ultraviolet, X-ray, infrared and radio waves that radiate from stars and other celestial objects. A stellar spectrum can reveal many properties of stars, such as their chemical composition, temperature, density, mass, distance and luminosity. Spectroscopy can show the velocity of motion towards or away from the observer by measuring the Doppler shift. Spectroscopy is also used to study the physical properties of many other types of celestial objects such as planets, nebulae, galaxies, and active galactic nuclei. Background Astronomical spectroscopy is used to measure three major bands of radiation in the electromagnetic spectrum: visible light, radio waves, and X-rays. While all spectroscopy looks at specific bands of the spectrum, different methods are required to acquire the signal depending on the frequency. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometer
A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, photodiode, or photomultiplier. Photometers measure: *Illuminance * Irradiance * Light absorption * Scattering of light * Reflection of light *Fluorescence *Phosphorescence * Luminescence Historically, photometry was done by estimation, comparing the luminous flux of a source with a standard source. By the 19th century, common photometers included Rumford's photometer, which compared the depths of shadows cast by different light sources, and Ritchie's photometer, which relied on equal illumination of surfaces. Another type was based on the extinction of shadows. Modern photometers utilize photoresistors, photodiodes or photomultipliers to detect light. Some models employ photon counting, measuring light by counting individual photons. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Materials Science
Materials science is an interdisciplinary field of researching and discovering materials. Materials engineering is an engineering field of finding uses for materials in other fields and industries. The intellectual origins of materials science stem from the Age of Enlightenment, when researchers began to use analytical thinking from chemistry, physics, and engineering to understand ancient, phenomenological observations in metallurgy and mineralogy. Materials science still incorporates elements of physics, chemistry, and engineering. As such, the field was long considered by academic institutions as a sub-field of these related fields. Beginning in the 1940s, materials science began to be more widely recognized as a specific and distinct field of science and engineering, and major technical universities around the world created dedicated schools for its study. Materials scientists emphasize understanding how the history of a material (''processing'') influences its struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruce Merrifield
Robert Bruce Merrifield (July 15, 1921 – May 14, 2006) was an American biochemist who won the Nobel Prize in Chemistry in 1984 for the invention of solid phase peptide synthesis. Early life He was born in Fort Worth, Texas, on 15 July 1921, the only son of George E. Merrifield and Lorene née Lucas. In 1923 the family moved to California where he attended nine grade schools and two high schools before graduating from Montebello High School in 1939. It was there that he developed an interest both in chemistry and in astronomy. After two years at Pasadena Junior College he transferred to the University of California at Los Angeles (UCLA). After graduation in chemistry he worked for a year at the Philip R. Park Research Foundation taking care of an animal colony and assisting with growth experiments on synthetic amino acid diets. One of these was the experiment by Geiger using the law of the minimum that first demonstrated that the essential amino acids must be present ''simultan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Scientist (magazine)
''The Scientist'' is a professional magazine intended for life scientists. ''The Scientist'' covers recently published research papers, current research, techniques, and other columns and reports of interest to its readers. The magazine is published monthly and is available in print and digital formats. Overview The main purpose of the magazine is to provide print and online coverage of the latest developments in life sciences research, technology, careers, and business. Subject matters covered by the magazine include groundbreaking research, industry innovations, careers, financial topics, the economics of science, scientific ethics, profiles of scientists, lab tools, scientific publishing, techniques, product spotlight, and guides. History ''The Scientist'' was founded in 1986 by American businessman Eugene Garfield as part of his academic publishing service ''Institute for Scientific Information.'' The publishing house was sold two years later to ''JPT Publishing'', but Eug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckman Coulter
Beckman Coulter, Inc. is a Danaher Corporation company that develops, manufactures, and markets products relevant to biomedical testing. It operates in the industries of diagnostics under the brand name Beckman Coulter and life sciences under the brand name Beckman Coulter Life Sciences. The company was established in 1935 as National Technical Laboratories, and has become an international company through growth and acquisitions of other life sciences organizations. The company employs over 12,000 people, with $5.8 billion in annual sales by 2017. It is currently headquartered in Brea, California. Beckman Coulter was acquired by Danaher Corporation in 2011. History The company was founded by Caltech professor Arnold O. Beckman in 1935 as National Technical Laboratories to commercialize a pH meter that he had invented. In the 1940s, Beckman changed the name to Arnold O. Beckman, Inc. to sell oxygen analyzers, the ''Helipot'' precision potentiometer, and spectrophotometers. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arnold O
Arnold may refer to: People * Arnold (given name), a masculine given name * Arnold (surname), a German and English surname Places Australia * Arnold, Victoria, a small town in the Australian state of Victoria Canada * Arnold, Nova Scotia United Kingdom * Arnold, East Riding of Yorkshire * Arnold, Nottinghamshire United States * Arnold, California, in Calaveras County * Arnold, Carroll County, Illinois * Arnold, Morgan County, Illinois * Arnold, Iowa * Arnold, Kansas * Arnold, Maryland * Arnold, Mendocino County, California * Arnold, Michigan * Arnold, Minnesota * Arnold, Missouri * Arnold, Nebraska * Arnold, Ohio * Arnold, Pennsylvania * Arnold, Texas * Arnold, Brooke County, West Virginia * Arnold, Lewis County, West Virginia * Arnold, Wisconsin * Arnold Arboretum of Harvard University, Massachusetts * Arnold Township, Custer County, Nebraska Other uses * Arnold (automobile), a short-lived English car * Arnold of Manchester, a former English coachbuilder * Arnold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Flux Density
In spectroscopy, spectral flux density is the quantity that describes the rate at which energy is transferred by electromagnetic radiation through a real or virtual surface, per unit surface area and per unit wavelength (or, equivalently, per unit frequency). It is a radiometric rather than a photometric measure. In SI units it is measured in W m−3, although it can be more practical to use W m−2 nm−1 (1 W m−2 nm−1 = 1 GW m−3 = 1 W mm−3) or W m−2 μm−1 (1 W m−2 μm−1 = 1 MW m−3), and respectively by W·m−2·Hz−1, Jansky or solar flux units. The terms irradiance, radiant exitance, radiant emittance, and radiosity are closely related to spectral flux density. The terms used to describe spectral flux density vary between fields, sometimes including adjectives such as "electromagnetic" or "radiative", and sometimes dropping the word "density". Applications include: *Characterizing remote telesco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Celestial Object
An astronomical object, celestial object, stellar object or heavenly body is a naturally occurring physical entity, association, or structure that exists within the observable universe. In astronomy, the terms ''object'' and ''body'' are often used interchangeably. However, an astronomical body or celestial body is a single, tightly bound, contiguous entity, while an astronomical or celestial ''object'' is a complex, less cohesively bound structure, which may consist of multiple bodies or even other objects with substructures. Examples of astronomical objects include planetary systems, star clusters, nebulae, and galaxies, while asteroids, moons, planets, and stars are astronomical bodies. A comet may be identified as both a body and an object: It is a ''body'' when referring to the frozen nucleus of ice and dust, and an ''object'' when describing the entire comet with its diffuse coma and tail. History Astronomical objects such as stars, planets, nebulae, asteroids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond atmosphere of Earth, Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Egyptian astronomy, Egyptians, Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Chinese astronomy, Chinese, Maya civilization, M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
