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Resolution 2398(XXIII)
Resolution(s) may refer to: Common meanings * Resolution (debate), the statement which is debated in policy debate * Resolution (law), a written motion adopted by a deliberative body * New Year's resolution, a commitment that an individual makes at New Year's Day * Dispute resolution, the settlement of a disagreement Science, technology, and mathematics Mathematics and logic * Resolution (algebra), an exact sequence in homological algebra * Resolution (logic), a rule of inference used for automated theorem proving * Standard resolution, the bar construction of resolutions in homological algebra * Resolution of singularities in algebraic geometry Measurements * Resolution (audio), a measure of digital audio quality * Resolution (electron density), the quality of an X-ray crystallography or cryo-electron microscopy data set * Angular resolution, the capability of an optical or other sensor to discern small objects * Depositional resolution, the age difference of foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Resolution
Optical resolution describes the ability of an imaging system to resolve detail, in the object that is being imaged. An imaging system may have many individual components, including one or more lenses, and/or recording and display components. Each of these contributes (given suitable design, and adequate alignment) to the optical resolution of the system; the environment in which the imaging is done often is a further important factor. Lateral resolution Resolution depends on the distance between two distinguishable radiating points. The sections below describe the theoretical estimates of resolution, but the real values may differ. The results below are based on mathematical models of Airy discs, which assumes an adequate level of contrast. In low-contrast systems, the resolution may be much lower than predicted by the theory outlined below. Real optical systems are complex, and practical difficulties often increase the distance between distinguishable point sources. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiral Resolution
Chiral resolution, or enantiomeric resolution, is a process in stereochemistry for the separation of racemic compounds into their enantiomers. It is an important tool in the production of optically active compounds, including drugs. Another term with the same meaning is optical resolution. The use of chiral resolution to obtain enantiomerically pure compounds has the disadvantage of necessarily discarding at least half of the starting racemic mixture. Asymmetric synthesis of one of the enantiomers is one means of avoiding this waste. Crystallization of diastereomeric salts The most common method for chiral resolution involves conversion of the racemic mixture to a pair of diastereomeric derivatives by reacting them with chiral derivatizing agents, also known as chiral resolving agents. The derivatives which are then separated by conventional crystallization, and converted back to the enantiomers by removal of the resolving agent. The process can be laborious and depends on the div ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resolution (beam Engine)
''Resolution'' was an early beam engine, installed between 1781–1782 at Coalbrookdale as a water-returning engine to power the blast furnaces and ironworks there. It was one of the last water-returning engines to be constructed, before the rotative beam engine made this type of engine obsolete. Water power in Coalbrookdale Coalbrookdale was a cradle of the First Industrial Revolution and was the scene of Abraham Darby's first production of iron by a coke-fired blast furnace, rather than the previous and expensive charcoal. Coalbrookdale is a narrow steep-sided valley that offered useful water power to drive the furnace blast and the various stamp mills, boring engines, etc. Contemporary visitors commented upon the picturesque 'fine cascades' of water. Although the water power available at Coalbrookdale had been described as 'abundant', it was also seasonal: in the summer months, the lack of water could require the furnace to be 'blown out' for some months and work suspend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit In The Last Place
In computer science and numerical analysis, unit in the last place or unit of least precision (ulp) is the spacing between two consecutive floating-point numbers, i.e., the value the least significant digit (rightmost digit) represents if it is 1. It is used as a measure of accuracy in numeric calculations. Definition One definition is: In radix b with precision p, if b^e \le , x, x. Otherwise, \operatorname (x + 1) = x or \operatorname (x + 1) = x + \operatorname(x), depending on the value of the least significant digit and the exponent of x. This is demonstrated in the following Haskell code typed at an interactive prompt: > until (\x -> x x+1) (+1) 0 :: Float 1.6777216e7 > it-1 1.6777215e7 > it+1 1.6777216e7 Here we start with 0 in single precision and repeatedly add 1 until the operation does not change the value. Since the significand for a single-precision number contains 24 bits, the first integer that is not exactly representable is 224+1, and this value rounds to 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Resolution
Temporal resolution (TR) refers to the discrete resolution of a measurement with respect to time. Physics Often there is a trade-off between the temporal resolution of a measurement and its spatial resolution, due to Heisenberg's uncertainty principle. In some contexts, such as particle physics, this trade-off can be attributed to the finite speed of light and the fact that it takes a certain period of time for the photons carrying information to reach the observer. In this time, the system might have undergone changes itself. Thus, the longer the light has to travel, the lower the temporal resolution. Technology Computing In another context, there is often a tradeoff between temporal resolution and computer storage. A transducer may be able to record data every millisecond, but available storage may not allow this, and in the case of 4D PET imaging the resolution may be limited to several minutes. Electronic displays In some applications, temporal resolution may instead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spatial Resolution
In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resolution is directly connected to angular resolution, other instruments, like synthetic aperture radar or a network of weather stations, produce data whose spatial sampling layout is more related to the Earth's surface, such as in remote sensing and satellite imagery. See also * Image resolution * Ground sample distance * Level of detail * Resel In image analysis, a resel (from ''res''olution ''el''ement) represents the actual spatial resolution in an image or a volumetric dataset. The number of resels in the image may be lower or equal to the number of pixel/voxels in the image. In an act ... References Accuracy and precision {{physics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resolution (mass Spectrometry)
In mass spectrometry, resolution is a measure of the ability to distinguish two peaks of slightly different mass-to-charge ratios ''ΔM'', in a mass spectrum. Resolution and resolving power There are two different definitions of resolution and resolving power in mass spectrometry. IUPAC definition The IUPAC definition for resolution in mass spectrometry is :R = \cfrac = \mathrm :\Delta M = \mathrm :M = \mathrm Where a larger resolution indicates a better separation of peaks. This definition is used in a number of mass spectrometry texts. This use is also implied by the term "high-resolution mass spectrometry." A high value for resolution corresponding to good separation of peaks is similar to the convention used with chromatography separations, although it is important to note that the definitions are not the same. High resolution indicating better peak separation is also used in ion mobility spectrometry. Resolving power definition Some mass spectrometrists use the definit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resolution (chromatography)
In chromatography, resolution is a measure of the separation of two Summit (topography), peaks of different retention time ''t'' in a chromatogram. Expression Chromatographic peak resolution is given by :R_s = 2\cfrac where tR is the retention time and wb is the peak width at baseline. Here compound 1 elutes before compound 2. If the peaks have the same width :R_s = \cfrac . Plate number The theoretical plate height is given by :H = \frac where L is the column length and N the number of theoretical plates. The relation between plate number and peak width at the base is given by :N = 16 \cdot \left(\frac\right)^2 \,. See also *Van Deemter equation *Resolution (mass spectrometry) *Image resolution References External linksIUPAC Nomenclature for Chromatography {{chromatography, Chromatography, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrometer
A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the spectral components are somehow mixed. In visible light a spectrometer can separate white light and measure individual narrow bands of color, called a spectrum. A mass spectrometer measures the spectrum of the masses of the atoms or molecules present in a gas. The first spectrometers were used to split light into an array of separate colors. Spectrometers were developed in early studies of physics, astronomy, and chemistry. The capability of spectroscopy to determine chemical composition drove its advancement and continues to be one of its primary uses. Spectrometers are used in astronomy to analyze the chemical composition of stars and planets, and spectrometers gather data on the origin of the universe. Examples of spectrometers are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Resolution
The spectral resolution of a spectrograph, or, more generally, of a frequency spectrum, is a measure of its ability to resolve features in the electromagnetic spectrum. It is usually denoted by \Delta\lambda, and is closely related to the resolving power of the spectrograph, defined as R = \frac, where \Delta\lambda is the smallest difference in wavelengths that can be distinguished at a wavelength of \lambda. For example, the Space Telescope Imaging Spectrograph (STIS) can distinguish features 0.17 nm apart at a wavelength of 1000 nm, giving it a resolution of 0.17 nm and a resolving power of about 5,900. An example of a high resolution spectrograph is the ''Cryogenic High-Resolution IR Echelle Spectrograph'' (CRIRES+) installed at ESO's Very Large Telescope, which has a spectral resolving power of up to 100,000. Doppler effect The spectral resolution can also be expressed in terms of physical quantities, such as velocity; then it describes the difference between vel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
