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In crystallography, a diffraction standard, or calibration crystal, is a crystal used to calibrate an X-ray spectrometer to an absolute X-ray energy scale. Quartz or silicon crystals are typically used. There are also reports of crystals of silver behenate or silver stearate having been used for this purpose.
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X-ray crystallography (XRC) is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angles and intensities of these diffracted beams, a crystallographer can produce a three-dimensional picture of the density of electrons within the crystal. From this electron density, the mean positions of the atoms in the crystal can be determined, as well as their chemical bonds, their crystallographic disorder, and various other information.
X-ray fluorescence (XRF) is the emission of characteristic "secondary" X-rays from a material that has been excited by being bombarded with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis and chemical analysis, particularly in the investigation of metals, glass, ceramics and building materials, and for research in geochemistry, forensic science, archaeology and art objects such as paintings
In X-ray crystallography, wide-angle X-ray scattering (WAXS) or wide-angle X-ray diffraction (WAXD) is the analysis of Bragg peaks scattered to wide angles, which are caused by sub-nanometer-sized structures. It is an X-ray-diffraction method and commonly used to determine a range of information about crystalline materials. The term WAXS is commonly used in polymer sciences to differentiate it from SAXS but many scientists doing "WAXS" would describe the measurements as Bragg/X-ray/powder diffraction or crystallography.
X-ray scattering techniques are a family of non-destructive analytical techniques which reveal information about the crystal structure, chemical composition, and physical properties of materials and thin films. These techniques are based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy.
BeppoSAX was an Italian–Dutch satellite for X-ray astronomy which played a crucial role in resolving the origin of gamma-ray bursts (GRBs), the most energetic events known in the universe. It was the first X-ray mission capable of simultaneously observing targets over more than 3 decades of energy, from 0.1 to 300 kiloelectronvolts (keV) with relatively large area, good energy resolution and imaging capabilities. BeppoSAX was a major programme of the Italian Space Agency (ASI) with the participation of the Netherlands Agency for Aerospace Programmes (NIVR). The prime contractor for the space segment was Alenia while Nuova Telespazio led the development of the ground segment. Most of the scientific instruments were developed by the Italian National Research Council (CNR) while the Wide Field Cameras were developed by the Netherlands Institute for Space Research (SRON) and the LECS was developed by the astrophysics division of the European Space Agency's ESTEC facility.
Copper(II) nitrate, Cu(NO3)2, is an inorganic compound that forms a blue crystalline solid. Anhydrous copper nitrate forms deep blue-green crystals and sublimes in a vacuum at 150-200 °C. Copper nitrate also occurs as five different hydrates, the most common ones being the hemipentahydrate and trihydrate.
Scheelite is a calcium tungstate mineral with the chemical formula CaWO4. It is an important ore of tungsten (wolfram). Well-formed crystals are sought by collectors and are occasionally fashioned into gemstones when suitably free of flaws. Scheelite has been synthesized using the Czochralski process; the material produced may be used to imitate diamond, as a scintillator, or as a solid-state lasing medium. It was also used in radium paint in the same fashion as was zinc sulphide, and Thomas Edison invented a fluoroscope with a calcium tungstate-coated screen, making the images six times brighter than those with barium platinocyanide; the latter chemical allowed Röntgen to discover X-rays in early November 1895.
An electron microprobe (EMP), also known as an electron probe microanalyzer (EPMA) or electron micro probe analyzer (EMPA), is an analytical tool used to non-destructively determine the chemical composition of small volumes of solid materials. It works similarly to a scanning electron microscope: the sample is bombarded with an electron beam, emitting x-rays at wavelengths characteristic to the elements being analyzed. This enables the abundances of elements present within small sample volumes to be determined, when a conventional accelerating voltage of 15-20 kV is used. The concentrations of elements from lithium to plutonium may be measured at levels as low as 100 parts per million (ppm), material dependent, although with care, levels below 10 ppm are possible The ability to quantify lithium by EPMA became a reality in 2008.
Zinc selenide (ZnSe) is a light-yellow, solid compound comprising zinc (Zn) and selenium (Se). It is an intrinsic semiconductor with a band gap of about 2.70 eV at 25 °C (77 °F). ZnSe rarely occurs in nature, and is found in the mineral that was named after Hans Stille called "stilleite."
Orchestral Favorites is an album by Frank Zappa first released in May 1979 on his own DiscReet Records label. The album is entirely instrumental and features music performed by the 37-piece Abnuceals Emuukha Electric Symphony Orchestra. It reached #168 on the Billboard 200 album chart in the United States.
The aim of color calibration is to measure and/or adjust the color response of a device to a known state. In International Color Consortium (ICC) terms, this is the basis for an additional color characterization of the device and later profiling. In non-ICC workflows, calibration refers sometimes to establishing a known relationship to a standard color space in one go. The device that is to be calibrated is sometimes known as a calibration source; the color space that serves as a standard is sometimes known as a calibration target. Color calibration is a requirement for all devices taking an active part of a color-managed workflow, and is used by many industries, such as television production, gaming, photography, engineering, chemistry, medicine and more.
Blu-ray Disc Recordable (BD-R) refers to two direct to disc optical disc recording technologies that can be recorded on to a Blu-ray-based optical disc with an optical disc recorder. BD-R discs can be written to once, whereas Blu-ray Disc Recordable Erasable (BD-RE) can be erased and re-recorded multiple times. Disc capacities are 25 GB for single-layer discs, 50 GB for double-layer discs, 100 GB ("XL") for triple-layer, and 128 GB for quadruple-layer.
Silver behenate is a silver salt of the long-chain fatty acid behenic acid. It is a possible low-angle diffraction standard that was characterized using the powder diffraction technique.
Small-angle X-ray scattering (SAXS) is a small-angle scattering technique by which nanoscale density differences in a sample can be quantified. This means that it can determine nanoparticle size distributions, resolve the size and shape of (monodisperse) macromolecules, determine pore sizes, characteristic distances of partially ordered materials, and much more. This is achieved by analyzing the elastic scattering behaviour of X-rays when travelling through the material, recording their scattering at small angles. It belongs to the family of small-angle scattering (SAS) techniques along with small-angle neutron scattering, and is typically done using hard X-rays with a wavelength of 0.07 – 0.2 nm.. Depending on the angular range in which a clear scattering signal can be recorded, SAXS is capable of delivering structural information of dimensions between 1 and 100 nm, and of repeat distances in partially ordered systems of up to 150 nm. USAXS can resolve even larger dimensions, as the smaller the recorded angle, the larger the object dimensions that are probed.
SilverFast is the name of a family of software for image scanning and processing, including photos, documents and slides, developed by LaserSoft Imaging.
Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast, and resolution of the film.
Christopher Graham Rapley is a British scientist. He is Professor of Climate Science at University College London, a Fellow of St Edmund's College Cambridge, a member of the Academia Europaea, Chair-elect of the European Science Foundation's European Space Sciences Committee, Patron of the Surrey Climate Commission, a member of the Science Museum’s Science Advisory Board, and member of the UK Clean Growth Fund Advisory Board. His previous posts include Director of the Science Museum (London), Director of the British Antarctic Survey, Chairman of the London Climate Change Partnership, President of the Scientific Committee on Antarctic Research, Vice President of the European Science Foundation's European Polar Board, Executive Director of the International Geosphere-Biosphere Programme, and founder - leader of UCL Mullard Space Science Laboratory's (MSSL) Remote Sensing Group. In the 1970s he was instrument scientist on two Skylark rocket payloads flown from Woomera, Australia to study the Soft X-ray Diffuse Background, on four Aerobee flights for White Sands, New Mexico in collaboration with the Lockheed Missile and Space Co's (LMSC) Palo Alto research laboratory to test a new design of solar X-ray spectrometer. He was instrument scientist for the Bent Crystal Spectrometer and Flat Crystal Spectrometer detector package flown on NASA’s Solar Maximum Mission as part of the X-Ray Polychromator provided by UCL MSSL, LMSC and the Rutherford Appleton Laboratory. In 1994 whilst on a sabbatical at NASA's Jet Propultion Laboratory he contributed to the design of the Cassini RADAR instrument. He led numerous ESA funded studies on the use of radar altimeters to study Earth’s polar ice, land and inland water, underpinning the ESA Earth Observation satellite series ERS-1, ERS-2, and Envisat. The MSSL group provided the on-board calibration sources for the UK Along-Track Scanning Radiometer flown on the same spacecraft. He was Chair of the International Council of Science - World Meteorological Organisation's International Planning Group for the International Polar Year 2007-2008 and a member of the IPY Steering Committee. From 2012-2016 he was a member, then Chair, of the European Space Agency Director General’s High-Level Science Policy Advisory Committee. His current interests are in the role of climate scientists in society, the communication of climate science and the need to better balance the discovery of new facts about the climate system and the delivery of benefit to society. He is Chair of the UCL Policy Commission on Communicating Climate Science. In 2014 Prof Rapley and the playwright Duncan Macmillan wrote the acclaimed play 2071 which Prof Rapley performed in 2014/15 at the Royal Court Theatre and in Hamburg and Brussels. The book is available from John Murray. More recently Prof Rapley was the Science Consultant on BBC1’s ‘Climate Change – The Facts’ presented by Sir David Attenborough. He has recently been appointed as the science advisor on a BBC1 four-part series on the Swedish climate activist, Greta Thunberg. In 2003 Prof Rapley was appointed CBE by Her Majesty the Queen. In 2008 he was awarded the Edinburgh Science Medal for having made 'a significant contribution to the understanding and wellbeing of humanity'
In crystallography, a Greninger chart is a chart that allows angular relations between zones and planes in a crystal to be directly read from an x-ray diffraction photograph.
Enrico Costa is an Italian astrophysicist, known for studies of gamma ray bursts (GRBs).
John Michael Squire was professor of structural biophysics in the University of London, a visiting professor at Imperial College London and a research fellow at the University of Bristol, where he researched muscle contraction and blood vessel glycocalyx structure. He was a Fellow of both the Institute of Physics and the Society of Biology. He was an emeritus member of the US Biophysical Society and an honorary member of the British Biophysical Society.