|
Spectrophotometers
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, and infrared radiation, modern spectrophotometers can interrogate wide swaths of the electromagnetic spectrum, including x-ray, ultraviolet, visible, infrared, and/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-absorption, and sometimes a percentage of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DU Spectrophotometer
The DU spectrophotometer or Beckman DU, introduced in 1941, was the first commercially viable scientific instrument for measuring the amount of ultraviolet light absorbed by a substance. This model of spectrophotometer enabled scientists to easily examine and identify a given substance based on its absorption spectrum, the pattern of light absorbed at different wavelengths. Arnold O. Beckman's National Technical Laboratories (later Beckman Instruments) developed three in-house prototype models (A, B, C) and one limited distribution model (D) before moving to full commercial production with the DU. Approximately 30,000 DU spectrophotometers were manufactured and sold between 1941 and 1976. Sometimes referred to as a UV–Vis spectrophotometer because it measured both the ultraviolet (UV) and visible spectra, the DU spectrophotometer is credited as being a truly revolutionary technology. It yielded more accurate results than previous methods for determining the chemical compositi ... [...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 History Before electronic light sensitive elements were developed, photometry was done by estimation by the eye. The relative luminous flux of a source was compared with a standard source. The photometer is placed such that the illuminance from the source being investigated is equal to the standard source, as the human eye can judge equal illuminance. The relative luminous fluxes can then be calculated as the illuminance decreases proportionally to the inverse square of distance. A standard example of such a photometer consists of a piece of paper with an o ... [...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 ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then "M ... 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Scientist (magazine)
''The Scientist'' is a professional magazine intended for life scientists. Coverage includes articles on recently published research papers, current research, techniques, important career news, profiles of established and up and coming scientists, publishing, research integrity and best practices, as well as other columns and reports of interest to its readers. The editor-in-chief is Bob Grant. 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 matter covered by the magazine includes: groundbreaking research, industry innovations, careers, financial topics, economics of science, scientific ethics, profiles of scientists, lab tools, scientific publishing, techniques, product spotlight, and guides History ''The Scientist'' was founded by Eugene Garfield in 1986. In 1988, Garfield sold ''The Scientist'', part of the ''Institute for Scientific Informat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beckman Coulter
Beckman Coulter Inc. is a Danaher Corporation company that develops, manufactures, and markets products that simplify, automate and innovate complex biomedical testing. It operates in two industries: Diagnostics and Life Sciences. For more than 80 years, Beckman Coulter Inc. has helped healthcare and laboratory professionals, pharmaceutical and biotechnology companies, universities, medical schools, and research institutions worldwide. The company eventually grew to employ 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 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 the 1950s, the company name ch ... [...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 (band), ... [...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 telescop ... [...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 object, physical entity, association, or structure that exists in 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 galaxy, galaxies, while asteroids, natural satellite, moons, planets, and stars are astronomical bodies. A comet may be identified as both body and object: It is a ''body'' when referring to the frozen Comet nucleus, nucleus of ice and dust, and an ''object'' when describing the entire comet with its diffuse Coma (cometary), coma and Comet tail, tail. Hi ... [...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 frequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, 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 Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Egyptian astronomy, Egyptians, Chinese astronomy, Chinese, Maya civilization, Maya, and many anc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
