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Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages. Two different chromatographic columns are connected in sequence, and the effluent from the first system is transferred onto the second column. Typically the... | 0 | Chromatography + Titration + pH indicators |
A wallpaper is a mathematical object covering a whole Euclidean plane by repeating a motif indefinitely, in manner that certain isometries keep the drawing unchanged. For each wallpaper there corresponds a group of congruent transformations, with function composition as the group operation. Thus, a wallpaper group (or ... | 1 | Crystallography |
Heteroepitaxial growth is classified into three primary growth modes-- Volmer–Weber (VW), Frank–van der Merwe (FM) and Stranski–Krastanov (SK).
In the VW growth regime, the epitaxial film grows out of 3D nuclei on the growth surface. In this mode, the adsorbate-adsorbate interactions are stronger than adsorbate-surface... | 1 | Crystallography |
Antibody elution is the process of removing antibodies that are attached to their targets, such as the surface of red blood cells. Techniques include using heat, a freeze-thaw cycle, ultrasound, acids or organic solvents. No single method is best in all situations. | 0 | Chromatography + Titration + pH indicators |
In the isometric system, the most common types of twins are the Spinel Law (twin plane, parallel to an octahedron) <111>, where the twin axis is perpendicular to an octahedral face, and the Iron Cross <001>, which is the interpenetration of two pyritohedrons, a subtype of dodecahedron.
In the hexagonal system, calcite ... | 1 | Crystallography |
For over 150 years, scientists from all around the world have known about the crystallization of protein molecules.
In 1840, Friedrich Ludwig Hünefeld accidentally discovered the formation of crystalline material in samples of earthworm blood held under two glass slides and occasionally observed small plate-like crysta... | 1 | Crystallography |
The strictest form of order in a solid is lattice periodicity: a certain pattern (the arrangement of atoms in a unit cell) is repeated again and again to form a translationally invariant tiling of space. This is the defining property of a crystal. Possible symmetries have been classified in 14 Bravais lattices and 230 ... | 1 | Crystallography |
The Wigner–Seitz cell always has the same point symmetry as the underlying Bravais lattice. For example, the cube, truncated octahedron, and rhombic dodecahedron have point symmetry O, since the respective Bravais lattices used to generate them all belong to the cubic lattice system, which has O point symmetry. | 1 | Crystallography |
Crystal violet or gentian violet, also known as methyl violet 10B or hexamethyl pararosaniline chloride, is a triarylmethane dye used as a histological stain and in Gram's method of classifying bacteria. Crystal violet has antibacterial, antifungal, and anthelmintic (vermicide) properties and was formerly important as ... | 0 | Chromatography + Titration + pH indicators |
The Martin Medal is an award given for outstanding contributions to the advancement of separation science. The award is presented by The Chromatographic Society, a UK-based organization promoting all aspects of chromatography and related separation techniques. The award is named after Professor Archer J.P Martin, who c... | 0 | Chromatography + Titration + pH indicators |
The metric tensor is sometimes used for calculations involving the unit cell and is defined (in matrix form) as:
In two dimensions,
In three dimensions,
The distance between two points and in the unit cell can be determined from the relation:
The distance from the origin of the unit cell to a point within the unit ... | 1 | Crystallography |
#Rutile (TiO) frequently exhibits a prismatic or acicular growth habit. In the presence of alkali dopants or a solid-state ZrSiO dopant, rutile has been observed to crystallise from an anatase parent-phase in the form of abnormally large grains existing in a matrix of finer, equiaxed anatase or rutile grains.
# Alumina... | 1 | Crystallography |
A slurry of resin, such as DEAE-Sephadex is poured into the column. The matrix that is used is insoluble with charged groups that are covalently attached. These charged groups are referred to as exchangers like cation and anion exchangers. After it settles, the column is pre-equilibrated in buffer before the protein m... | 0 | Chromatography + Titration + pH indicators |
It can complement X-ray crystallography for studies of very small crystals (<0.1 micrometers), both inorganic, organic, and proteins, such as membrane proteins, that cannot easily form the large 3-dimensional crystals required for that process. Protein structures are usually determined from either 2-dimensional crystal... | 1 | Crystallography |
Any periodic tiling can be seen as a wallpaper. More particularly, we can consider as a wallpaper a tiling by identical tiles edge‑to‑edge, necessarily periodic, and conceive from it a wallpaper by decorating in the same manner every tiling element, and eventually erase partly or entirely the boundaries between these t... | 1 | Crystallography |
Thermal laser epitaxy (TLE) is a physical vapor deposition technique that utilizes irradiation from continuous-wave lasers to heat sources locally for growing films on a substrate. This technique can be performed under ultra-high vacuum pressure or in the presence of a background atmosphere, such as ozone, to deposit ... | 1 | Crystallography |
Gentian violet has antibacterial, antifungal, antihelminthic, antitrypanosomal, antiangiogenic, and antitumor properties. It is used medically for these properties, in particular for dentistry, and is also known as "pyoctanin" (or "pyoctanine"). It is commonly used for:
* Marking the skin for surgery preparation and al... | 0 | Chromatography + Titration + pH indicators |
* The analyst wishes to simplify the conduct of a variety of titrations by using one sensor for all. For example, a laboratory might conduct routinely acid/base, redox, complexometric, sulfate and chloride titrations. A single thermometric sensor in conjunction with an autosampler will enable all titrations to be perfo... | 0 | Chromatography + Titration + pH indicators |
The reciprocal to a simple hexagonal Bravais lattice with lattice constants and is another simple hexagonal lattice with lattice constants and rotated through 90° about the c axis with respect to the direct lattice. The simple hexagonal lattice is therefore said to be self-dual, having the same symmetry in reciproc... | 1 | Crystallography |
MCP-RHEED is a system in which an electron beam is amplified by a micro-channel plate (MCP). This system consists of an electron gun and an MCP equipped with a fluorescent screen opposite to the electron gun. Because of the amplification, the intensity of the electron beam can be decreased by several orders of magnitud... | 1 | Crystallography |
In 1925, Coward received a Rockefeller Fellowship to continue her studies and research on vitamin A in the Department of Agricultural Chemistry at the University of Wisconsin–Madison under Dr. Harry Steenbock. On her return to Britain, she was appointed head of the Nutrition Department of the Royal Pharmaceutical... | 0 | Chromatography + Titration + pH indicators |
The principles involved can be understood by considering the most efficient way of packing together equal-sized spheres and stacking close-packed atomic planes in three dimensions. For example, if plane A lies beneath plane B, there are two possible ways of placing an additional atom on top of layer B. If an additional... | 1 | Crystallography |
PED possesses many advantageous attributes that make it well suited to investigating crystal structures via direct methods approaches:
# Quasi-kinematical diffraction patterns: While the underlying physics of the electron diffraction is still dynamical in nature, the conditions used to collect PED patterns minimize man... | 1 | Crystallography |
Phenol red, sometimes labelled with a different name, such as "Guardex Solution #2", is used as a pH indicator in home swimming pool test kits.
Chlorine can result in the bleaching of the dye in the absence of thiosulfate to inhibit the oxidizing chlorine. High levels of bromine can convert phenol red to bromophenol re... | 0 | Chromatography + Titration + pH indicators |
Alizarine Yellow R is produced by azo coupling of salicylic acid and diazonium derivative of 4-Nitroaniline | 0 | Chromatography + Titration + pH indicators |
Blood plasma is the liquid component of blood, which contains dissolved proteins, nutrients, ions, and other soluble components. In whole blood, red blood cells, white blood cells, and platelets are suspended within the plasma. The goal of plasma purification and processing is to extract specific materials that are pre... | 0 | Chromatography + Titration + pH indicators |
* The advantages of an oxidation-reduction reactor in gas chromatography include
* The reactor ensures uniform sensitivity to most organic molecules, leading to consistent and reliable detection across a wide range of analytes.
* By eliminating the need for multiple calibrations and standards, the reactor increases the... | 0 | Chromatography + Titration + pH indicators |
In crystallography, a crystallographic point group is a three dimensional point group whose symmetry operations are compatible with a three dimensional crystallographic lattice. According to the crystallographic restriction it may only contain one-, two-, three-, four- and sixfold rotations or rotoinversions. This redu... | 1 | Crystallography |
The aforementioned hydrodynamic and hydrostatic instruments may be employed in a variety of ways, or modes of operation, in order to address the particular separation needs of the scientist. Many modes of operation have been devised to take advantage of the strengths and potentialities of the countercurrent chromatogra... | 0 | Chromatography + Titration + pH indicators |
Common sphere packings taken on by atomic systems are listed below with their corresponding packing fraction.
* Hexagonal close-packed (HCP): 0.74
* Face-centered cubic (FCC): 0.74 (also called cubic close-packed, CCP)
* Body-centered cubic (BCC): 0.68
* Simple cubic: 0.52
* Diamond cubic: 0.34
The majority of metals t... | 1 | Crystallography |
Centrifugal partition chromatography is a special chromatographic technique where both stationary and mobile phase are liquid, and the stationary phase is immobilized by a strong centrifugal force. Centrifugal partition chromatography consists of a series-connected network of extraction cells, which operates as element... | 0 | Chromatography + Titration + pH indicators |
Different methods to determine the equivalence point include:
;pH indicator: A pH indicator is a substance that changes color in response to a chemical change. An acid-base indicator (e.g., phenolphthalein) changes color depending on the pH. Redox indicators are also frequently used. A drop of indicator solution is add... | 0 | Chromatography + Titration + pH indicators |
Although there are several commercially available universal pH indicators, most are a variation of a formula patented by Yamada in 1933. | 0 | Chromatography + Titration + pH indicators |
Much of the past research into the composition and toxicity of UCM hydrocarbons has been conducted by the Petroleum and Environmental Geochemistry Group (PEGG) at the University of Plymouth, UK. As well as the hydrocarbon UCM, oils also contain more polar compounds such as those containing oxygen, sulphur or nitrogen. ... | 0 | Chromatography + Titration + pH indicators |
By far the most common and perhaps standard form of ionization is electron ionization (EI). The molecules enter into the MS (the source is a quadrupole or the ion trap itself in an ion trap MS) where they are bombarded with free electrons emitted from a filament, not unlike the filament one would find in a standard lig... | 0 | Chromatography + Titration + pH indicators |
In ion exchange chromatography, the Gibbs–Donnan effect is observed when the pH of the applied buffer and the ion exchanger differ, even up to one pH unit. For example, in anion-exchange columns, the ion exchangers repeal protons so the pH of the buffer near the column differs is higher than the rest of the solvent. As... | 0 | Chromatography + Titration + pH indicators |
The simple cubic Bravais lattice, with cubic primitive cell of side , has for its reciprocal a simple cubic lattice with a cubic primitive cell of side (or in the crystallographer's definition). The cubic lattice is therefore said to be self-dual, having the same symmetry in reciprocal space as in real space. | 1 | Crystallography |
In the RHEED setup, only atoms at the sample surface contribute to the RHEED pattern. The glancing angle of incident electrons allows them to escape the bulk of the sample and to reach the detector. Atoms at the sample surface diffract (scatter) the incident electrons due to the wavelike properties of electrons.
The di... | 1 | Crystallography |
CrysTBox offers tools for automated processing of diffraction patterns and high-resolution transmission electron microscope images. Since the tools employ algorithms of artificial intelligence and computer vision, they are designed to require minimal operator effort providing higher accuracy compared to manual evaluati... | 1 | Crystallography |
Macle is a term used in crystallography. It is a crystalline form, twin-crystal or double crystal (such as chiastolite). It is crystallographic twin according to the spinel twin law and is seen in octahedral crystals or minerals such as diamond and spinel. The twin law name comes from the fact that is commonly observed... | 1 | Crystallography |
Order strengthening brought about from the interaction of dislocations with ordered precipitates, forming anti-phase boundaries as dislocations move throughout the crystal, can lead to significant increases in strength and creep resistance. For this reason, order strengthening is often exploited for high-temperature cr... | 1 | Crystallography |
In microbiology, methyl red is used in the methyl red test (MR test), used to identify bacteria producing stable acids by mechanisms of mixed acid fermentation of glucose (cf. Voges–Proskauer test).
The MR test, the "M" portion of the four IMViC tests, is used to identify enteric bacteria based on their pattern of gluc... | 0 | Chromatography + Titration + pH indicators |
Anthocyanins are approved for use as food colorants in the European Union, Australia, and New Zealand, having colorant code E163. In 2013, a panel of scientific experts for the European Food Safety Authority concluded that anthocyanins from various fruits and vegetables have been insufficiently characterized by safety ... | 0 | Chromatography + Titration + pH indicators |
In materials science, the Burgers vector, named after Dutch physicist Jan Burgers, is a vector, often denoted as , that represents the magnitude and direction of the lattice distortion resulting from a dislocation in a crystal lattice. | 1 | Crystallography |
Weak affinity chromatography (WAC) is an affinity chromatography technique for affinity screening in drug development. WAC is an affinity-based liquid chromatographic technique that separates chemical compounds based on their different weak affinities to an immobilized target. The higher affinity a compound has towards... | 0 | Chromatography + Titration + pH indicators |
Similar to yttrium, rare-earth metals from Gd to Lu can form REBSi-type boride. The first such compound was synthesized by solid-state reaction and its structure was deduced as YB. X-ray powder diffraction (XRD) and electron diffraction indicated that YB has an orthorhombic structure with lattice constants a = 1.66251(... | 1 | Crystallography |
Redox titrations are based on a reduction-oxidation reaction between an oxidizing agent and a reducing agent. A potentiometer or a redox indicator is usually used to determine the endpoint of the titration, as when one of the constituents is the oxidizing agent potassium dichromate. The color change of the solution fr... | 0 | Chromatography + Titration + pH indicators |
Dye-ligand affinity chromatography is one of the Affinity chromatography techniques used for protein purification of a complex mixture. Like general chromatography, but using dyes to apply on a support matrix of a column as the stationary phase that will allow a range of proteins with similar active sites to bind to, r... | 0 | Chromatography + Titration + pH indicators |
The column is a glass or plastic cylinder packed with beads of resin and filled with buffer solution. It is normally mounted vertically with the buffer flowing downward from top to bottom. A glass frit at the bottom of the column retains the resin beads in the column while allowing the buffer and dissolved proteins to ... | 0 | Chromatography + Titration + pH indicators |
In geometry and crystallography, a Bravais lattice, named after , is an infinite array of discrete points generated by a set of discrete translation operations described in three dimensional space by
where the n are any integers, and a are primitive translation vectors, or primitive vectors, which lie in different dire... | 1 | Crystallography |
The simplest approach is to connect two commercial columns in series, which is termed a “tandem column”. Another approach is “biphasic column”, by packing two stationary phases separately in two ends of the same column. The third approach is to homogenize two or more different types of stationary phases in a single col... | 0 | Chromatography + Titration + pH indicators |
LC–MS is frequently used in drug development because it allows quick molecular weight confirmation and structure identification. These features speed up the process of generating, testing, and validating a discovery starting from a vast array of products with potential application. LC–MS applications for drug developme... | 0 | Chromatography + Titration + pH indicators |
The Wyckoff positions are named after Ralph Walter Graystone Wyckoff, an American X-ray crystallographer who authored several books in the field. His 1922 book, The Analytical Expression of the Results of the Theory of Space Groups, contained tables with the positional coordinates, both general and special, permitted b... | 1 | Crystallography |
In chemistry, isomorphism has meanings both at the level of crystallography and at a molecular level. In crystallography, crystals are isomorphous if they have identical symmetry and if the atomic positions can be described with a set of parameters (unit cell dimensions and fractional coordinates) whose numerical valu... | 1 | Crystallography |
The heat of neutralization of a fully dissociated acid with a fully dissociated base is approximately –56kJ/mol. The reaction is thus strongly exothermic, and is an excellent basis for a wide range of analysis in industry. An advantage for the industrial analyst is that the use of stronger titrants (1 to 2 mol/L) permi... | 0 | Chromatography + Titration + pH indicators |
The ÄKTA explorer was the first high end FPLC (Fast Protein Liquid Chromatography) system that was developed for Life Science research by the Swedish company Pharmacia in 1994. Its purpose was to simplify and automatize protein purification. It was followed by a line of similar devices (the "Äkta" line). The product li... | 0 | Chromatography + Titration + pH indicators |
There has been a growing interest in the application of IC in the analysis of pharmaceutical drugs. IC is used in different aspects of product development and quality control testing. For example, IC is used to improve stabilities and solubility properties of pharmaceutical active drugs molecules as well as used to det... | 0 | Chromatography + Titration + pH indicators |
4-Nitrophenol can be used as a pH indicator. A solution of 4-nitrophenol appears colorless below pH 5.4 and yellow above pH 7.5. This color-changing property makes this compound useful as a pH indicator.
The yellow color of the 4-nitrophenolate form (or 4-nitrophenoxide) is due to a maximum of absorbance at 405 nm (ε... | 0 | Chromatography + Titration + pH indicators |
Chemical additives are small chemical compounds that are added to the crystallization process to increase the yield of crystals. The role of small molecules in protein crystallization had not been well thought of in the early days since they were thought of as contaminants in most case. Smaller molecules crystallize be... | 1 | Crystallography |
Anthocyanins may have a protective role in plants against extreme temperatures. Tomato plants protect against cold stress with anthocyanins countering reactive oxygen species, leading to a lower rate of cell death in leaves. | 0 | Chromatography + Titration + pH indicators |
The frit fast atom bombardment (FAB) and continuous flow-FAB (CF-FAB) interfaces were developed in 1985 and 1986 respectively. Both interfaces were similar, but they differed in that the first used a porous frit probe as connecting channel, while CF-FAB used a probe tip. From these, the CF-FAB was more successful as a ... | 0 | Chromatography + Titration + pH indicators |
The Zener ratio is only applicable to cubic crystals. To overcome this limitation, a Universal Elastic Anisotropy Index (AU) was formulated from variational principles of elasticity and tensor algebra. The AU is now used to quantify the anisotropy of elastic crystals of all classes. | 1 | Crystallography |
If the SAD is taken from one a or a few single crystals, the diffractogram depicts a regular pattern of bright spots. Since the diffraction pattern can be seen as a two-dimensional projection of reciprocal crystal lattice, the pattern can be used to measure lattice constants, specifically the distances and angles betw... | 1 | Crystallography |
Desalting spin columns are widely available with various volumes and MWCO limits:
* [http://www.piercenet.com/cat/desalting-columns Thermo Scientific Pierce Products]
* [http://www.bio-rad.com/en-us/category/bio-spin-micro-bio-spin-size-exclusion-columns Bio-Rad Laboratories, Inc.]
* [https://www.cytivalifesciences.com... | 0 | Chromatography + Titration + pH indicators |
After the discovery of x-rays by Wilhelm Röntgen in 1895, and of the principles of X-ray diffraction by Laue and the Bragg family, it took several decades for the benefits of diffraction imaging to be fully recognized, and the first useful experimental techniques to be developed. The first systematic reports of laborat... | 1 | Crystallography |
* Orbifold signature:
* Coxeter notation: [4,4]
* Lattice: square
* Point group: D
* The group p4g has two centres of rotation of order four (90°), which are each other's mirror image, but it has reflections in only two directions, which are perpendicular. There are rotations of order two (180°) whose centres are loca... | 1 | Crystallography |
Many of the crystallographic point groups share the same internal structure. For example, the point groups , 2, and m contain different geometric symmetry operations, (inversion, rotation, and reflection, respectively) but all share the structure of the cyclic group C. All isomorphic groups are of the same order, but n... | 1 | Crystallography |
Phenolphthalein has been used for over a century as a laxative, but is now being removed from over-the-counter laxatives over concerns of carcinogenicity. Laxative products formerly containing phenolphthalein have often been reformulated with alternative active ingredients: Feen-a-Mint switched to bisacodyl, and Ex-Lax... | 0 | Chromatography + Titration + pH indicators |
Acidic solutions of fluoride (including hydrofluoric acid) can be determined by a simple thermometric titration with boric acid.
: B(OH) + 3F + 3H ↔ BF + 3HO
The titration plot illustrated in Figure 19 shows that the endpoint is quite rounded, suggesting that the reaction might not proceed to stoichiometric equilibrium... | 0 | Chromatography + Titration + pH indicators |
In a crystal, a superstructure manifests itself through additional reflections in diffraction patterns, e.g., in low energy electron diffraction (LEED) or X-ray diffraction experiments. Often a set of weak diffraction spots appears between the stronger spots belonging to what is referred to as the substructure. In some... | 1 | Crystallography |
The Bragg condition is correct for very large crystals. Because the scattering of X-rays and neutrons is relatively weak, in many cases quite large crystals with sizes of 100 nm or more are used. While there can be additional effects due to crystal defects, these are often quite small. In contrast, electrons interact t... | 1 | Crystallography |
Though the terms equivalence point and endpoint are often used interchangeably, they are different terms. Equivalence point is the theoretical completion of the reaction: the volume of added titrant at which the number of moles of titrant is equal to the number of moles of analyte, or some multiple thereof (as in poly... | 0 | Chromatography + Titration + pH indicators |
The previously described work of Martin and Synge impacted the development of the previously known column chromatography and inspired new forms of chromatography such as countercurrent distribution, paper chromatography, and gas-liquid chromatography which is more commonly known as gas chromatography. The modification ... | 0 | Chromatography + Titration + pH indicators |
A Chromatography column is a device used in chromatography for the separation of chemical compounds. A chromatography column contains the stationary phase, allowing the mobile phase to pass through it. Chromatography columns of different types are used in both gas and liquid chromatography. | 0 | Chromatography + Titration + pH indicators |
Thorin (also called thoron or thoronol) is an indicator used in the determination of barium, beryllium, lithium, uranium and thorium compounds. Being a compound of arsenic, it is highly toxic. | 0 | Chromatography + Titration + pH indicators |
Gas chromatography-mass spectrometry (GC-MS) is a two-dimensional chromatography technique that combines the separation technique of gas chromatography with the identification technique of mass spectrometry. GC-MS is the single most important analytical tool for the analysis of volatile and semi-volatile organic compou... | 0 | Chromatography + Titration + pH indicators |
Solid-phase epitaxy (SPE) is a transition between the amorphous and crystalline phases of a material. It is usually produced by depositing a film of amorphous material on a crystalline substrate, then heating it to crystallize the film. The single-crystal substrate serves as a template for crystal growth. The annealing... | 1 | Crystallography |
Stable isotope mass spectrometry is conducted in the Department of Geography, and was recently used by the Landmark Trust to determine very precisely the age of the timber from Llwyn Celyn farmhouse to the year 1420. | 0 | Chromatography + Titration + pH indicators |
The name "gentian violet" (or Gentianaviolett in German) is thought to have been introduced by the German pharmacist Georg Grübler, who in 1880 started a company in Leipzig that specialized in the sale of staining reagents for histology. The gentian violet stain marketed by Grübler probably contained a mixture of methy... | 0 | Chromatography + Titration + pH indicators |
High performance affinity chromatography (HPAC) works by passing a sample solution through a column packed with a stationary phase that contains an immobilized biologically active ligand. The ligand is in fact a substrate that has a specific binding affinity for the target molecule in the sample solution. The target mo... | 0 | Chromatography + Titration + pH indicators |
Two dimensional space has the same number of crystal systems, crystal families, and lattice systems. In 2D space, there are four crystal systems: oblique, rectangular, square, and hexagonal. | 1 | Crystallography |
An acid–base titration is a method of quantitative analysis for determining the concentration of Brønsted-Lowry acid or base (titrate) by neutralizing it using a solution of known concentration (titrant). A pH indicator is used to monitor the progress of the acid–base reaction and a titration curve can be constructed.
... | 0 | Chromatography + Titration + pH indicators |
The retention factor (R) may be defined as the ratio of the distance travelled by the solute to the distance travelled by the solvent. It is used in chromatography to quantify the amount of retardation of a sample in a stationary phase relative to a mobile phase. R values are usually expressed as a fraction of two deci... | 0 | Chromatography + Titration + pH indicators |
The use of displacement chromatography is rather limited, and is mostly used for preparative chromatography. The basic principle is based on a molecule with a high affinity for the chromatography matrix (the displacer) which is used to compete effectively for binding sites, and thus displace all molecules with lesser a... | 0 | Chromatography + Titration + pH indicators |
The fourth shell includes programs on representation theory of space and point groups. [http://www.cryst.ehu.es/rep/repres.html REPRES] constructs little group and full group irreducible representations for a given space group and a k-vector; [http://www.cryst.ehu.es/rep/correl.html CORREL] deals with the correlations ... | 1 | Crystallography |
A close packed unit cell, both face-centered cubic and hexagonal close packed, can form two different shaped holes. Looking at the three green spheres in the hexagonal packing illustration at the top of the page, they form a triangle-shaped hole. If an atom is arranged on top of this triangular hole it forms a tetrah... | 1 | Crystallography |
* Cost of reactor and replacements (each replacement unit costs ~ $6000)
* Addition of dead volume causes an increase in peak broadening depending on the GC column flow rates and molecule types (5-10% broadening is typical)
** Heteroatoms and oxidation of Polyarc transfer lines increase this broadening
* Susceptible t... | 0 | Chromatography + Titration + pH indicators |
TLC is a useful tool for reaction monitoring. For this, the plate normally contains a spot of starting material, a spot from the reaction mixture, and a co-spot (or cross-spot) containing both. The analysis will show if the starting material disappeared and if any new products appeared. This provides a quick and easy w... | 0 | Chromatography + Titration + pH indicators |
In reversed-phase (e.g. aqueous mobile phase) elution, the aqueous phase is used as the mobile phase with a less polar stationary phase. In countercurrent chromatography the same solvent system may be used in either normal or reversed phase mode simply by switching the direction of mobile phase flow through the column. | 0 | Chromatography + Titration + pH indicators |
Phases can also be inferred by using a process called molecular replacement, where a similar molecules already-known phases are grafted onto the intensities of the molecule at hand, which are observationally determined. These phases can be obtained experimentally from a homologous molecule or if the phases are known f... | 1 | Crystallography |
In geometry, the dyakis dodecahedron /ˈdʌɪəkɪsˌdəʊdɪkəˈhiːdrən/ or diploid is a variant of the deltoidal icositetrahedron with pyritohedral symmetry, transforming the kite faces into chiral quadrilaterals. It is the dual of the cantic snub octahedron. It can be constructed by enlarging 24 of the 48 faces of the disdyak... | 1 | Crystallography |
Anthocyanins are thought to be subject to physiochemical degradation in vivo and in vitro. Structure, pH, temperature, light, oxygen, metal ions, intramolecular association, and intermolecular association with other compounds (copigments, sugars, proteins, degradation products, etc.) generally are known to affect the c... | 0 | Chromatography + Titration + pH indicators |
The mobile phase or eluent is a solvent or a mixture of solvents used to move the compounds through the column. It is chosen so that the retention factor value of the compound of interest is roughly around 0.2 - 0.3 in order to minimize the time and the amount of eluent to run the chromatography. The eluent has also be... | 0 | Chromatography + Titration + pH indicators |
Tandem mass spectrometry (Tandem MS or MS/MS) uses two mass analyzers in sequence to separate more complex mixtures of analytes. The advantage of tandem MS is that it can be much faster than other two-dimensional methods, with times ranging from milliseconds to seconds. Because there is no dilution with solvents in MS,... | 0 | Chromatography + Titration + pH indicators |
After successful formation of a stable nucleus, a growth stage ensues in which free particles (atoms or molecules) adsorb onto the nucleus and propagate its crystalline structure outwards from the nucleating site. This process is significantly faster than nucleation. The reason for such rapid growth is that real crysta... | 1 | Crystallography |
In geometry and crystallography, the Laves graph is an infinite and highly symmetric system of points and line segments in three-dimensional Euclidean space, forming a periodic graph. Three equal-length segments meet at 120° angles at each point, and all cycles use ten or more segments. It is the shortest possible trip... | 1 | Crystallography |
The compound has uses ranging from medicine to laboratory syntheses of chemically similar compounds. o-Cresophthalein has been used to derive polyamides and polyimides, colorimetrically estimate calcium in serum, and predict amount of time to wait before blood collection after a patient receives gadodiamide. | 0 | Chromatography + Titration + pH indicators |
The extraction cells consist of hollow bodies with inlets and outlets of liquid connection. The cells are first filled with the liquid chosen to be the stationary phase. Under rotation, the pumping of the mobile phase is started, which enters the cells from the inlet. When entering the flow of mobiles phase forms small... | 0 | Chromatography + Titration + pH indicators |
To carry out metal cation titrations using EDTA, it is almost always necessary to use a complexometric indicator to determine when the end point has been reached. Common indicators are organic dyes such as Fast Sulphon Black, Eriochrome Black T, Eriochrome Red B, Patton Reeder, or Murexide. Color change shows that th... | 0 | Chromatography + Titration + pH indicators |
* Coupled substitutions are common in the silicate minerals where substitutes for in tetrahedral sites.
For example, when a plagioclase feldspar solid solution series forms, albite (Na Al SiO) can change to anorthite (Ca AlSiO) by having replace . However, this leaves a negative charge that has to be balanced by the... | 1 | Crystallography |
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