Refimprove date July 2008 Image Spektrofotometri.jpg thumb 300px Spectrophotometer In chemistry , spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. ref Allen, D., Cooksey, C., & Tsai, B. 2010, October 5 . Spectrophotometry. Retrieved from http www.nist.gov pml div685 grp03 spectrophotometry.cfm ref It is more specific than the general term electromagnetic spectroscopy in that spectrophotometry deals with Visible spectrum visible light, near ultraviolet , and near infrared , but does not cover time resolved spectroscopy time resolved spectroscopic techniques. Spectrophotometry involves the use of a spectrophotometer. A spectrophotometer is a photometer a device for measuring light intensity that can measure intensity as a function of the light source wavelength. Important features of spectrophotometers are spectral bandwidth and linear range of absorption or reflectance measurement. Spectrophotometers are commonly used for the measurement of transmittance or reflectance of solutions, transparent or opaque solids, such as polished glass, or gases. However they can also be designed to measure the diffusivity ... and calibrations . ref Allen, D., Cooksey, C., & Tsai, B. 2010, October 5 . Spectrophotometry ... 17 ref An example of an experiment in which spectrophotometry is used is the determination of the equilibrium ... of the solution can be tested using spectrophotometry. The amount of light that passes through ... relative to the initial substance . ref name george UV visible spectrophotometry main Ultraviolet ... as well. Visible region 400 700 nm spectrophotometry is used extensively in colorimetry science ... , plastic , or quartz glass quartz . IR spectrophotometry main Infrared spectroscopy Spectrophotometers .... Samples for IR spectrophotometry may be smeared between two discs of potassium bromide or ground ... Spectrophotometry Atomic emission spectroscopy Inductively coupled plasma atomic emission spectroscopy ... more details
Spectrometry may refer to Ion mobility spectrometry , an analytical technique used to separate and identify ionized molecules in the gas phase based on their ion mobility in a carrier buffer gas Mass spectrometry , an analytical technique that measures the mass to charge ratio of charged particles Rutherford backscattering spectrometry , an analytical technique used to determine the structure and composition of materials by measuring the backscattering of a beam of high energy ions impinging on a sample Neutron triple axis spectrometry , a technique used in inelastic neutron scattering See also Spectrometer Spectrophotometry Spectroscopy disambig ... more details
Photometry can refer to Photometry optics , the science of measurement of visible light in terms of its perceived brightness to human vision Photometry astronomy , the measurement of the flux or intensity of an astronomical object s electromagnetic radiation Spectrophotometry , the measurement of spectral distribution along with the flux or intensity See also Radiometry disambig es Fotometr a desambiguaci n fr Photom trie sr ... more details
orphan date August 2010 infobox tool name GeneQuant image Genequant.jpg image size caption other name classification types used with inventor manufacturer model related GeneQuant is a Electronic test equipment tool that can be used to measure the concentration of nucleic acid and protein from a sample. The basic principle of this tool is to measure the absorbance of the sample at 230, 260, 280, 320, 546, 562, 595 and 600 nm, so it works like a Spectrophotometry spectrophotometer . Category Laboratory equipment biology stub id GeneQuant ... more details
A fluorometer or fluorimeter is a device used to measure parameters of fluorescence its intensity and wavelength distribution of emission spectrum after Excitation spectrum excitation by a certain spectrum of light. ref http www.scribd.com doc 10514060 Fluorescence Spectrophotometry ref These parameters are used to identify the presence and the amount of specific molecules in a medium. Modern fluorometers are capable of detecting fluorescent molecule concentrations as low as 1 part per trillion. Fluorescence analysis can be orders of magnitude more sensitive than other techniques. Applications include chemistry biochemistry , medicine , Environmental quality environmental monitoring. For instance, they are used to measure chlorophyll fluorescence to investigate plant physiology. Fluorometer types Filter fluorometer Spectrofluorometer See also Fluorescence spectroscopy , for a fuller discussion of instrumentation Chlorophyll fluorescence , to investigate plant ecophysiology. Radiometer , to measure various electromagnetic radiation Spectrometer , to analyze spectrum of electromagnetic radiation Scatterometer , to measure scattered radiation Category Laboratory equipment Category Electromagnetic radiation meters es Fluor metro it Fluorimetro nl Fluorimeter sv Fluorimeter Reflist http www.scribd.com doc 10514060 Fluorescence Spectrophotometry ... more details
Summary A traditional skin color map based on the data of Biasutti. Data for native populations collected by R. Biasutti prior to 1940. Sources http biology.plosjournals.org perlserv ?request get document&doi 10.1371 2Fjournal.pbio.0000027 , http anthro.palomar.edu vary vary 1.htm Reflectance spectrophotometry is a much more modern way of measurement of human skin color. See Jablonski s work http www.bgsu.edu departments chem faculty leontis chem447 PDF files Jablonski skin color 2000.pdf http anthro.palomar.edu adapt images map of skin color distribution.gif Note Based on the map here Image Map of skin hue equi.png but without the white streak across Morocco and Algeria. Filled it with an intermediate skin tone value, like Biasutti s own map shows. Licensing GFDL migration relicense ... more details
chembox verifiedrevid 400116938 ImageFile Indophenol.svg ImageSize IUPACName 4 4 hydroxyphenyl iminocyclohexa 2,5 dien 1 one OtherNames Section1 Chembox Identifiers ChemSpiderID Ref chemspidercite correct chemspider ChemSpiderID 9951 InChI 1 C12H9NO2 c14 11 5 1 9 2 6 11 13 10 3 7 12 15 8 4 10 h1 8,14H InChIKey RSAZYXZUJROYKR UHFFFAOYAS StdInChI Ref stdinchicite correct chemspider StdInChI 1S C12H9NO2 c14 11 5 1 9 2 6 11 13 10 3 7 12 15 8 4 10 h1 8,14H StdInChIKey Ref stdinchicite correct chemspider StdInChIKey RSAZYXZUJROYKR UHFFFAOYSA N CASNo 500 85 6 PubChem 10379 SMILES O C 2 C C C N c1ccc O cc1 C C 2 Section2 Chembox Properties C 12 H 9 N 1 O 2 Appearance Density MeltingPt BoilingPt Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition Indophenol is an artificial blue metachromatic dye , obtained by the action of Phenols phenol on certain nitrogenous derivatives of quinone . ref http dictionary.reference.com browse indophenol Definition of indophenol from Dictionary.com ref Indophenol resembles the color indigo in appearance. Dichlorphenolindophenol Dichlorophenol indophenol DCPIP , a form of indophenol, is often used to determine the presence of vitamin C , or ascorbic acid . ref http www3.interscience.wiley.com journal 113291042 abstract?CRETRY 1&SRETRY 0 Ascorbic acid and indophenol ref The formation of indophenol is used to determine ammonia and paracetamol by spectrophotometry. ref Tsuboi, T. Hirano, Y. Shibata, Y. Motomizu, S. Sensitivity Improvement of Ammonia Determination Based on Flow Injection Indophenol Spectrophotometry with Manganese II Ion as a Catalyst and Analysis of Exhaust Gas of Thermal Power Plant, Analytical Sciences, October 2002, Vol. 18, pp. 1141 4 ref Indophenol blue CAS 132 31 0 is a completely different molecule with systematic name N p dimethylaminophenyl 1,4 naphthoquinoneimine . ref http www.sciencemag.org cgi content abstract 139 3557 835 Systematic name of idophenol blue ref References references Category Indopheno ... more details
Unreferenced date December 2009 In chemistry , the path length is defined as the distance that light UV Visible spectrum VIS travels through a sample in an analytical cell. Typically, a sample cell is made of quartz , glass, or a plastic rhombic cuvette with a volume typically ranging from 0.1 mL to 10 mL or larger used in a spectrophotometer . For the purposes of spectrophotometry i.e. when making calculations using the Beer Lambert law the path length is measured in centimeters rather than in meters . In a computer network , the path length is one of many possible router metrics used by a router to help determine the best Routing route among multiple routes to a destination. It consists of the end to end hop count from a source to a destination over the network. More simply, in general computer terminology, it can mean simply the total number of instructions executed from point A to point B in a program Instruction path length . In physics, the path length is defined as the total distance an object travels. Unlike displacement, which is the total distance an object travels from a starting point, path length is the total distance travelled, regardless of where it travelled. DEFAULTSORT Path Length Category Spectroscopy Category Computer networking Category Computing terminology ... more details
Spec may refer to spec is a music video or commercial which its creator produces at his own expense to improve his showreel in order to get a paid job. Often the people involved work for free and there is no video commissioner in between. spec script , a script written by an aspiring screenwriter to act as a sort of written audition as part of the process of obtaining representation by a literary agent Spec Ad , an advertising term used when an ad is built to the customers specifications Spec series , a description of Spec racing Spec Miata , a Spec racing class Spec Racer Ford , a Spec racing class Spec RX 7 , a Spec racing class Spectinomycin , an antibiotic Specification , an explicit set of requirements to be satisfied by a material, product, or service. Standard Performance Evaluation Corporation , an organization that produces benchmarks Columbia Daily Spectator , a student newspaper that is nicknamed the Spec Spectrum of a ring , a mathematical structure often written as Spec R Spectrophotometry Spectrophotometer , a device for measuring light intensity and wavelength. Speculation , hypothetical thinking Spec sheet or data sheet used to describe something technical GNU Compiler Collection spec file See also SPEC Spec sharp Spec disambig de SPEC ... more details
Orphan date September 2006 att March 2011 merge to titration date February 2011 Gas phase titration refers, generally, to any titration done in the gas phase . More specifically, it refers to a method for determining reactive species in the gas phase by reaction with an excess of some other gas, which acts as the titrant . Most commonly the gaseous analyte is ozone , which can be titrated with nitrogen oxide according to the reaction O sub 3 sub NO O sub 2 sub NO sub 2 sub . After the reaction is complete, the remaining titrant and the product can be quantified e.g., by Fourier transform spectroscopy FT IR this also gives the amount of analyte present in the original sample. Gas phase titration has two advantages over simple spectrophotometry. First, the measurement no longer depends on path length, since the same path length is used for the measurement of both the excess titrant and the product. Secondly, the measurement no longer depends on a linear change in absorbance as a function of analyte concentration Beer Lambert law . Finally, it is useful for samples containing species which interfere at wavelengths typically used for the analyte. References http www.bipm.fr en scientific chem gas titration.html Description from the Bureau International du Poids et Mesures Category Analytical chemistry ... more details
The Lieberman Burchard or acetic anhydride test is used for the detection of cholesterol . The formation of a green or green blue colour after a few minutes is positive. Lieberman Burchard is a reagent used in a colourimetric test http www.biology online.org dictionary Colourimetric test to detect cholesterol, which gives a deep green colour. This colour begins as a purplish, pink colour and progresses through to a light green then very dark green colour. The colour is due to the hydroxyl group OH of cholesterol reacting with the reagents and increasing the conjugation of the un saturation in the adjacent fused ring. Since this test uses acetic anhydride and sulfuric acid as reagent s, caution must be exercised so as not to receive severe burns. Method Dissolve one or two crystals of cholesterol in dry chloroform in a dry test tube. Add several drops of acetic anhydride and then 2 drops of conc.H sub 2 sub SO sub 4 sub and mix carefully. After the reaction finished, the concentration of cholesterol can be measured using spectrophotometry . References Campbell, Mary K. & Shawn O. Farrell. Biochemistry. 4th ed. . Singapore Thomson Asia Pte Ltd. 2005 . http www.clinchem.org cgi reprint 20 7 794.pdf Category Medical tests Med diagnostic stub ... more details
A photoelectric flame photometer is a device used in Inorganic chemistry inorganic chemical Analytical chemistry analysis to determine the concentration of certain metal ions, among them sodium , potassium , lithium , and calcium . In principle, it is a controlled flame test with the intensity of the flame colour quantified by photoelectric circuitry. The sample is introduced to the flame at a constant rate. Filters select which colours the photometer detects and exclude the influence of other ions. Before use, the device requires calibration with a series of standard solutions of the ion to be tested. Flame photometry is crude but cheap compared to Emission spectroscopy flame emission spectroscopy , where the emitted light is analysed with a monochromator. Its status is similar to that of the colorimeter which uses filters compared to the Spectrophotometry spectrophotometer which uses a monochromator . it also has the range of metals that could be analysed and the limit of detection are also considered References http www.articlesbase.com science articles flame photometers and how they work 2640727.html Category Inorganic chemistry ca Fot metre de flama pl Fotometria p omieniowa ... more details
Frank Scott Hogg June 26, 1904 &ndash January 1, 1951 was born to Dr. James Scott Hogg and Ida Barberon in Cambridge, Ontario Preston , Ontario . After earning and undergraduate degree from the University of Toronto, Hogg received the second doctorate in astronomy awarded at Harvard University in 1929 where he pioneered in the study of spectrophotometry of star s and of Electromagnetic spectrum spectra of comet s. ref cite web url http www.rasc.ca journal pdfs 1999 12.pdf title Canadian Astronomers who Earned the Ph.D. at Harvard in the Shapley Era work Hoffleit, Dorrit. Journal of the Royal Astronomical Society of Canada. December 1999, Volume No. 3, Number 6. 262 271 accessdate 2007 03 08 ref In September 1931, he married Helen Sawyer Hogg . During World War II, he developed a two star sextant for air navigation. He was the head of the Department of Astronomy at the University of Toronto and director of the David Dunlap Observatory from 1946 until his death. During this time he pursued the observatory s major research program to study the motions of faint stars in the line of sight. ref cite web url http www.thecanadianencyclopedia.com index.cfm?PgNm TCE&Params A1ARTA0003807 title Hogg, Frank Scott work Millman, Peter M. The Canadian Encyclopedia accessdate 2007 03 08 ref The crater Hogg crater Hogg on the Moon is co named for him and Arthur Robert Hogg Arthur Hogg . Notes references External links http www.thecanadianencyclopedia.com index.cfm?PgNm TCE&Params A1ARTA0003807 Frank Scott Hogg Persondata Metadata see Wikipedia Persondata . NAME Hogg, Frank Scott ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH PLACE OF BIRTH DATE OF DEATH PLACE OF DEATH DEFAULTSORT Hogg, Frank Scott Category 1904 births Category 1951 deaths Category Canadian astronomers Category University of Toronto alumni Category Harvard University alumni Category People from Cambridge, Ontario Category University of Toronto faculty Category Canadian people of Scottish descent astronomer stub Can ... more details
Expert subject Anatomy date February 2009 Image Cochlea crosssection.png thumb 300px Cross section of cochlea . Perilymph is located in the scala tympani and scala vestibuli the aqua regions at the top and bottom of the diagram. Perilymph is an extracellular fluid located within the cochlea part of the ear in two of its three compartments the scala tympani and scala vestibuli . The ionic composition of perilymph is comparable to that of Blood plasma plasma and cerebrospinal fluid . The major cation in perilymph is sodium The values of sodium and potassium concentration in the perilymph are 138 millimolar mM and 6.9 millimolar mM , respectively. ref cite journal author Bosher SK, Warren RL title Observations on the electrochemistry of the cochlear endolymph of the rat a quantitative study of its electrical potential and ionic composition as determined by means of flame spectrophotometry journal Proceedings of the Royal Society of London Series B, Biological Sciences volume 171 issue 1023 pages 227 247 date 1968 11 05 pmid 4386844 doi 10.1098 rspb.1968.0066 ref Perilymph versus Endolymph The inner ear has two parts the bony labyrinth and the membranous labyrinth . The membranous labyrinth is contained within the bony labyrinth, and within the membranous labyrinth is a fluid called endolymph. Between the outer wall of the membranous labyrinth and the wall of the bony labyrinth is the location of perilymph. Perilymph and endolymph have unique ionic compositions suited to their functions in regulating electrochemical impulses of hair cells. The electric potential of endolymph is 80 90 mV more positive than perilymph due to a higher concentration of K compared to Na. ref cite journal author Konishi T, Hamrick PE, Walsh PJ title Ion transport in guinea pig cochlea. I. Potassium and sodium transport journal Acta Otolaryngol volume 86 issue 1 2 pages 22 34 year 1978 pmid 696294 doi 10.3109 00016487809124717 ref Clinical significance It has also been suggested that ... more details
Image OpticalFlats157 03.jpg thumb Optical flats in case. About 1 inch 2.5 cm in diameter Image Optical flat interference fringes.jpg thumb Testing flatness of surfaces with optical flats. The lefthand surface is flat, the righthand surface is uneven. Optical flats are optical grade pieces of glass lapping lapped and polishing polished to be extremely flat on one or both sides, usually within a few millionths of an inch about 25 nanometres . They are used with a monochromatic light to determine the flatness of other optical surfaces by Interference wave propagation interference . ref cite book last English first R. E. editor first Albert G. editor last Ingalls editorlink Albert Graham Ingalls title Amateur Telescope Making Amateur Telescope Making, Book Three publisher Scientific American date 1953 pages 156 162 chapter Optical Flats isbn ref When an optical flat is placed on another surface, interference fringe s Newton s rings are seen due to interference in the tiny gap between the two surfaces. The spacing between the fringes is smaller where the gap is changing more rapidly, indicating a departure from flatness in one of the two surfaces, in a similar way to the contour lines on a map. A flat surface is indicated by a pattern of straight, parallel fringes with equal spacing, while other patterns indicate uneven surfaces. Two adjacent fringes indicate a difference in elevation of one half wavelength of the light used, so by counting the fringes differences in elevation of the surface can be measured to millionths of an inch. Usually only one of the two surfaces is made optically flat to the specified tolerance, and this surface is indicated by an arrow on the edge of the glass. Optical flats are sometimes given an optical coating and used as precision mirror s for special purposes, such as in a Fabry P rot interferometer or laser cavity . Optical flats have uses in spectrophotometry as well. Image Optical flats in use.jpg thumb left Optical flats being used to c ... more details
Unreferenced stub auto yes date December 2009 DISPLAYTITLE ortho Nitrophenyl galactoside Chembox Name ortho Nitrophenyl galactoside ImageFile ONPG structure.png ImageSize 200px IUPACName 2R,3R,4S,5R 2 Hydroxymethyl 6 2 nitrophenoxy oxane 3,4,5 triol OtherNames 2 Nitrophenylgalactoside Abbreviations ONPG Section1 Chembox Identifiers CASNo 19710 96 4 PubChem 123646 SMILES O N O C1 CC CC C1O C H 2O C H CO C H O C H O C H 2O MeSHName 2 nitrophenylgalactoside Section2 Chembox Properties Formula C sub 12 sub H sub 15 sub NO sub 8 sub MolarMass 301.249 Appearance Density MeltingPt BoilingPt Section3 Chembox Hazards Solubility MainHazards FlashPt Autoignition Lowercase ortho Nitrophenyl galactoside ortho Nitrophenyl galactoside ONPG is a colorimeter colorimetric and spectrophotometry spectrophotometric substrate biochemistry substrate for detection of beta galactosidase activity. This compound is normally colorless. However if galactosidase is present, it Hydrolysis hydrolyzes the ONPG molecule into galactose and ortho nitrophenol . The latter compound has a yellow color that can be used to check for enzyme activity by means of a Colorimeter colorimetric assay at 420 nm wavelength . galactosidase is required for lactose utilization, so the intensity of the color produced can be used as a measure of the enzymatic rate. Though ONPG mimics lactose and is hydrolyzed by galactosidase, it is unable to act as an inducer for the lac operon. Without another lactose analog that can act as an inducer, such as IPTG , galactosidase will not be transcribed and ONPG will not be hydrolyzed. Glycosides DEFAULTSORT Ortho Nitrophenyl Galactoside Category Galactosides Nitrophenyl galactoside, ortho Category Nitrobenzenes Biochem stub de O Nitrophenyl D galactopyranosid fr Ortho nitroph nyl galactoside ... more details
Orphan date February 2009 SIAscopy measures the amount of haemoglobin , melanin and collagen in the stratum corneum , Epidermis skin epidermis and dermis to a depth of 2 mm, and identifies whether melanin is present in the epidermis or the dermis. The information is presented as SIAscans, which show how these components vary over the skin. SIAscopy makes use of the way light interacts with skin the way it scatters or bounces and the amount absorbed by cells and other structures and how this varies for different wavelengths or colours of light and is based on Symon Cotton s Thesis PhD thesis . ref Cotton S. D 1998 A non invasive Medical imaging imaging system for assisting in the diagnosis of Melanoma malignant melanoma . PhD thesis. University of Birmingham Birmingham University , UK ref ref M. MONCRIEFF,S. COTTON, E. CLARIDGE AND P. HALL 2002 Spectrophotometric intracutaneous analysis a new technique for imaging pigmented skin lesions, British Journal of Dermatology 2002 146 448 457. ref Due to the multi layered structure of the skin, and because the most prominent chromophores have slowly varying spectral properties, it is possible to generate models which can predict the method of light transport within skin. This allows analysis of the skin using broadband Spectrophotometry spectrophotometric techniques. The device used to capture the information is a SIAscope. Image Skinmodel2.jpg thumb Optical model of the skin based on physics of image formation In order to generate the model, simulations are run for hundreds of thousands of different combinations of haemoglobin, melanin, collagen and dermal melanin. The result of each simulation represents how the camera would respond if it was to image the corresponding combination of skin chromophore s. This information is stored, and then interrogated during each scan in order to generate SIAscans. Each SIAscan is a bitmap representing the concentration of each chromophore on every pixel. Image siaa.JPG thumb Handhel ... more details
Unreferenced date May 2009 In spectrophotometry , the Compton edge is a feature of the spectrograph that results from the Compton scattering in the scintillator or Particle detector detector . When a gamma ray scatters off the scintillator but escapes, only a fraction of its energy is registered by the detector. This leads to a spectrum of gamma rays in the data that is not really there. The highest energy that occurs from this process is the Compton edge. Background File Am Be SourceSpectrum.jpg right thumb 300px Gamma spectrum of a radioactive Am Be source. In a Compton scattering process, an incident photon collides with an electron in a material. The amount of energy exchanged varies with angle, and is given by the formula math frac 1 E prime frac 1 E frac 1 m text e c 2 left 1 cos theta right math or math E prime frac E 1 frac 1 cos theta E m text e c 2 math E is the energy of the incident photon. E is the energy of the outgoing photon, which escapes the material. math m text e math is the mass of the electron. c is the speed of light. math theta math is the angle of deflection for the photon. The amount of energy transferred to the material varies with the angle of deflection. As math theta math approaches zero, none of the energy is transferred. The maximum amount of energy is transferred when math theta math approaches 180 degrees. math E T E E prime math math E text Compton E T text max frac 2E 2 m text e c 2 2E math It is impossible for the photon to transfer any more energy via this process, hence there is a sharp cutoff at this energy giving rise to the name Compton edge . See also Gamma ray spectroscopy Compton suppression DEFAULTSORT Compton Edge Category Spectroscopy Physics stub ar ... more details
nofootnotes date December 2010 Orphan date February 2009 Cleanup date September 2007 LBOZ is a coefficient used in spectrophotometry to estimate selectivity amount of overlapping of spectrum spectra in quantitative manner. It is named after its creators Lorber, Bergmann, von Oepen, and Zinn. Definition Image lboz spectra.png thumb right 300 px Sample synthetic spectra of four components Let math mathbf X math be a matrix of the spectra absorbances , where the k rows correspond to the components in mixture and n columns correspond to the sequence of wavelengths. The LBOZ criterion for k th component is calculated from the following formula math xi k frac 1 mathbf X k row mathbf X k col math where math mathbf X math means a pseudoinverse of the matrix and math cdots math means an Euclidean space euclidean length of a vector. Properties The image above show synthetic Gaussian function gaussian spectra. The LBOZ criteria are 0.561 for black compound, 0.402 for red compound, 0.899 for green and 0.549 for blue. LBOZ always lie in range 0,1 and has strong mathematical sense it presents the amount of spectral signal which is not overlapped by the others. Hence, the uncertainty of a compound quantity increases by math 1 xi math in presence of the other compounds. In this case, the highest uncertainty is expected during determination of red compound theoretically 2.38 times greater than during determination of its compound alone. Implementation The following function in GNU Octave Matlab can be useful to calculate LBOZ pre function ksi LBOZ X X X ksi 1. sqrt sum X. 2 . sum pinv X . 2 endfunction pre References A. Lorber, Anal. Chem. 58 1986 1167. A. Lorber, A. Harel, Z. Goldbart, I.B. Brenner, Anal. Chem. 59 1987 1260. G. Bergmann, B. von Oepen, P. Zinn, Anal. Chem. 59 1987 2522. Category Spectroscopy pl LBOZ ... more details
orphan date March 2010 Alexis Spectral Data is a software developed for colour matching processes that calculates from available spectral data the colour numbers used by computers to display colours on screen. It displays the colour for each reflectivity spectral reflectance curve and records the calculated tristimulus trichromatic values and colour numbers along with the spectral curves. This eliminates the need to scan the samples separately with a Truecolour Scanner while creating the database. The spectral data can be introduced manually as a series of reflectivity reflectance values at wavelength s measured in different standard illuminant s with an arbitrary but fixed increment that must be kept for each spectral curve throughout the creation of the whole database. Therefore, older UV VIS spectrophotometry Spectrophotometers that can t be Interface computer science interfaced with computers can also be used for creating the database needed for colour matching. ref Razvan Ion M. Preda, Maria Marcela Savu, Aurelia Meghea, Corneliu Tarabasanu Mihaila, Mathematical model for colour matching applied in sheepskin dyeing , IULTCS Centenary Congress, London 1997, Congress Proceedings, 798 803. ref Alexis Spectral Data determines the whiteness degree in a less time consuming method, which permits storage and easier handling of the obtained data. ref Maria Marcela Savu, Razvan Ion Preda, Florin Vrejoiu, Determination of whiteness degree for various leather support, 11th Congress of the Leather and Shoe Industries, Hungary 1998, 451 ref Alexis Spectral Data can export the tristimulus trichromatic values , calculated from the spectral curves, to Alexis Analyser, software that handles only trichromatic data. The earliest information about the development of this software comes from a paper published by a student at the Politehnica University of Bucharest University Politehnica Bucharest in 1993 ref Razvan Ion M. Preda, Mircea Popescu, True RGB colour analysis , Chemistry a ... more details
Water chemistry analyses are carried out to identify and quantify the chemical components and properties of a certain water. This include pH , major cation s and anion s, trace elements and isotope s. Water chemistry analysis is used extensively to determine the possible uses a water may have or to study the interaction it has with its environment. Water chemistry analysis is often the groundwork of studies of water quality , water pollution pollution , hydrology and geothermal water s. Analyzed components Components commonly analyzed are pH, the cations Sodium Na , Potassium K , Calcium Ca , Manganesium Mg , Si , the anions Chlorine Cl , Fluorine F , sulfate SO sub 4 sub , the trace metals and metalloids Rb , titanium Ti , Iron Fe , manganese Mn , etc., unstable volatiles such as carbon dioxide CO sub 2 sub , hydrogen sulfide H sub 2 sub S and oxygen O sub 2 sub , isotope ratios of isotopes of oxygen sup 18 sup O and deuterium sup 2 sup H , organic material and nutrient s. Methods Depending on the components, different methods are applied to determine the quantities or ratios of the components. While some methods can be performed with standard laboratory equipment, others require advanced devices, such as Inductively coupled plasma mass spectrometry ICP MS . Oxygen and hydrogen sulfide H sub 2 sub S are most commonly measured by titration . Ion chromatography is a sensitive and stable technique that can measure lithium Li , Ammonium NH sub 4 sub , Sodium Na , Potassium K , Calcium Ca and Magnesium Mg quantities among other components. For steam samples, gas chromatography can be used to determine methane , carbon dioxide , oxygen and nitrogen quantities. Spectrophotometry is most commonly used to measure iron content in water samples. Saturated calomel electrode and glass electrode are often used in conjunction to determine the pH of water. Category Analytical chemistry Category Geochemistry Category Water chemistry Analysis chemistry stub ro Analiza chimic a apei ... more details
chembox ImageFile Rufigallol.png ImageSize 200px ImageName Skeletal formula of rufigallol ImageFile1 Rufigallol 3D balls.png ImageSize1 210px ImageName1 Ball and stick model of rufigallol IUPACName 1,2,3,5,6,7 Hexahydroxyanthracene 9,10 dione OtherNames Rufigallic acid 1,2,3,5,6,7 Hexahydroxy 9,10 anthraquinone 1,2,3,5,6,7 Hexahydroxyanthracene 9,10 dione Section1 Chembox Identifiers CASNo 82 12 2 PubChem 65737 SMILES C1 C2C C C C1O O O C O C3 CC C C C3C2 O O O O Section2 Chembox Properties C 14 H 8 O 8 Appearance Density MeltingPt BoilingPt Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition Rufigallol or 1,2,3,5,6,7 hexahydroxy 9,10 anthraquinone is an organic compound with formula chem C 14 O 8 H 8 , which can be viewed as a derivative of anthraquinone through the replacement of six hydrogen atoms H by hydroxyl groups OH . The compound is soluble in dioxane , from which it crystallizes as red needles that sublime without melting at 365 C. ref name azim It can be obtained by treating gallic acid with concentrated sulfuric acid and then with sodium hydroxide . ref name azim Rufigallol is particularly toxic to the malaria l parasite Plasmodium falciparum and has a synergy synergistic effect in combination with the antimalarial drug exifone , which has structural sumilarities to rufigallol. ref name winter R. W. WINTER, KENNETH A. CORNELL, LINDA L. JOHNSON, MARINA IGNATUSHCHENKO,DAVID J. HINRICHS and MICHAEL K. RISCOE 1996 , Potentiation of the Antimalarial Agent Rufigallol . ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Vol. 40, No. 6, pages 1408 1411. http aac.asm.org cgi reprint 40 6 1408.pdf Online version accessed on 2010 02 01. Article has no DOI? doi ref Rufigallol forms a crimson colored complex with beryllium , aluminum , thorium , zirconium and hafnium , and this reaction has been used for the spot test spot and spectrophotometry spectrophotometric determination of beryllium in low concentrations. ref name azim M. A. Azim and A. A. Ayaz 1969 , Spe ... more details
wants to work in the Spectrophotometry report too, here it is for reference ref cite journal title Spectrophotometry Report of OSA Progress Committee for 1922 23 journal Journal of the Optical ... more details
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