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c_spiy0h42vsb7 | Then, logically, they should avoid synchronizing their cycles. By the same token, if males during the course of human evolution became valued by females for additional purposes – hunting and bringing home food, for example – then females should resist being controlled by dominant male harem-holders. If males are useful... | McClintock effect |
c_3bem95r59f83 | Under those circumstances, according to this argument, the logical strategy would be for females to synchronize as tightly as they can (see figure b, right).One implication is that there may be a link between the degree of synchrony in a population (whether seasonal, lunar or both), and the degree of reproductive egali... | McClintock effect |
c_nes3xahd1ror | On the other hand, while conceding that it would be impossible to get clockwork synchrony throughout an inter-birth interval, Power et al. argued that once we take account of birth seasonality – enhancing the effects of menstrual synchrony by clumping fertile cycles within a relatively brief time-window – it emerges th... | McClintock effect |
c_bszpq7szqw38 | It is suggested that the human female may once have had adaptive reasons for evolving such a cycle length – implying some theoretical potential for synchrony to a lunar clock – but did so in an African setting under prehistoric conditions which today no longer exist. Not all archaeologists accept that lunar periodicity... | McClintock effect |
c_b8rm8ugo7o6x | In order to work properly, a video card or graphics adapter must set a mode—a combination of screen resolution, color depth and refresh rate—that is within the range of values supported by itself and the attached display screen. This operation is called mode-setting, and it usually requires raw access to the graphics h... | Direct Rendering Manager |
c_5xxo4nbj0t0z | In early days, the user space programs that wanted to use the graphical framebuffer were also responsible for providing the mode-setting operations, and therefore they needed to run with privileged access to the video hardware. In Unix-type operating systems, the X Server was the most prominent example, and its mode-se... | Direct Rendering Manager |
c_8f0l3hnuiyw9 | It not only breaks the isolation that operating systems should provide between programs and hardware, raising both stability and security concerns, but also could leave the graphics hardware in an inconsistent state if two or more user space programs try to do the mode-setting at the same time. To avoid these conflicts... | Direct Rendering Manager |
c_1nk12kej2j6f | The XFree86-VidModeExtension extension was introduced in XFree86 3.1.2 to let any X client request modeline (resolution) changes to the X Server. VidMode extension was later superseded by the more generic XRandR extension. However, this was not the only code doing mode-setting in a Linux system. | Direct Rendering Manager |
c_pgjnyht14e8m | During the system booting process, the Linux kernel must set a minimal text mode for the virtual console (based on the standard modes defined by VESA BIOS extensions). Also the Linux kernel framebuffer driver contained mode-setting code to configure framebuffer devices. To avoid mode-setting conflicts, the XFree86 Serv... | Direct Rendering Manager |
c_ngnp2byfzat7 | One single failure or crash of one of these programs could leave the system without a working display due to a modeset misconfiguration, and therefore unusable. It was also impossible for the kernel to show error or debug messages when the screen was in a graphics mode—for example when X was running—since the only mode... | Direct Rendering Manager |
c_zal3uj40is8w | Then, every process—including the X Server—should be able to command the kernel to perform mode-setting operations, and the kernel would ensure that concurrent operations don't result in an inconsistent state. The new kernel API and code added to the DRM module to perform these mode-setting operations was called Kernel... | Direct Rendering Manager |
c_t9kzecm9rv5u | KMS also makes it easier to write alternative graphics systems, which now don't need to implement their own mode-setting code. By providing centralized mode management, KMS solves the flickering issues while changing between console and X, and also between different instances of X (fast user switching). | Direct Rendering Manager |
c_xxbt0dknhc91 | Since it is available in the kernel, it can also be used at the beginning of the boot process, saving flickering due to mode changes in these early stages. The fact that KMS is part of the kernel allows it to use resources only available at kernel space such as interrupts. For example, the mode recovery after a suspend... | Direct Rendering Manager |
c_8fvgnrivi7zs | The kernel also allows the hotplug of new display devices easily, solving a longstanding problem. Mode-setting is also closely related to memory management—since framebuffers are basically memory buffers—so a tight integration with the graphics memory manager is highly recommended. That's the main reason why the kernel... | Direct Rendering Manager |
c_8rygcfi37dpx | Any DRM driver can choose to provide the DRIVER_MODESET flag when it registers with the DRM core to indicate that supports the KMS API. Those drivers that implement Kernel Mode-Setting are often called KMS drivers as a way to differentiate them from the legacy—without KMS—DRM drivers. KMS has been adopted to such an ex... | Direct Rendering Manager |
c_z2ltwlyuxfoy | In order to work properly, it is important that both antenna circuits be carefully balanced. To start with the antennae have to be identical, with identical electrical properties in the wiring and the lengths of the leads adjusted to be equal. Since the antennae have inductance and capacitance due to their mechanical l... | Bellini-Tosi direction finder |
c_6o8ye34o34jl | For this reason a variety of systems were used to decrease the sensitivity of the radiogoniometer to mis-tuning. Primary among these was the aperiodic aerial concept, which described the mechanical layout of the radiogoniometer's internal wiring. By winding the sense coil wiring around a vertical cylinder, and wiring t... | Bellini-Tosi direction finder |
c_m72h0z1y542i | In order-theoretic mathematics, a graded partially ordered set is said to have the Sperner property (and hence is called a Sperner poset), if no antichain within it is larger than the largest rank level (one of the sets of elements of the same rank) in the poset. Since every rank level is itself an antichain, the Spern... | Sperner property of a partially ordered set |
c_ntcwe87slrzk | In order-theoretic mathematics, a series-parallel partial order is a partially ordered set built up from smaller series-parallel partial orders by two simple composition operations.The series-parallel partial orders may be characterized as the N-free finite partial orders; they have order dimension at most two. They in... | Series–parallel partial order |
c_egvyn9ha42ww | In order-theoretic mathematics, the deviation of a poset is an ordinal number measuring the complexity of a poset. A poset is also known as a partially ordered set. The deviation of a poset is used to define the Krull dimension of a module over a ring as the deviation of its poset of submodules. | Deviation of a poset |
c_jyz6pg0prsbh | In order: 2012-13: Philip Scott. 2013-14: David Hare. 2014-15: Nick Salter. 2015-16: Fiona Morrison. | Institute and Faculty of Actuaries |
c_5tctzqvkqvxt | 2016-17: Marjorie Ngwenya. 2017-18: Colin Wilson. 2018-19: Jules Constantinou. 2019-20: John Taylor. 2020-21: Tan Suee Chieh. | Institute and Faculty of Actuaries |
c_s831bzoc5yii | In ordinal ranking, all items receive distinct ordinal numbers, including items that compare equal. The assignment of distinct ordinal numbers to items that compare equal can be done at random, or arbitrarily, but it is generally preferable to use a system that is arbitrary but consistent, as this gives stable results ... | Ranking |
c_y4uswenwhmw9 | With this strategy, if A ranks ahead of B and C (which compare equal) which are both ranked ahead of D, then A gets ranking number 1 ("first") and D gets ranking number 4 ("fourth"), and either B gets ranking number 2 ("second") and C gets ranking number 3 ("third") or C gets ranking number 2 ("second") and B gets rank... | Ranking |
c_ktgvulo71yko | In ordinary Smalltalk code, without using HOM, obtaining a collection of the employees that have a salary of 1000 would be achieved with the following code: However, using HOM, it can be expressed as follows: Here, select is a higher order message, and hasSalary: is understood to be called on the select message itself,... | Higher order message |
c_m35dc09c5n4k | In ordinary circumstances, corporate service providers may not, or alternatively will not, act as a trustee for the clients which they provide services to. This is to maintain the integrity of the client organization and its ability to represent itself in legal processes. It also avoids excessive risk on behalf of the ... | Business services |
c_bvl0uo3pnw71 | In ordinary circumstances, striped hyenas are extremely timid around humans, though they may show bold behaviours toward people at night. On rare occasions, striped hyenas have preyed on humans. In the 1880s, a hyena was reported to have attacked humans, especially sleeping children, over a three-year period in the Eri... | Striped hyena |
c_4a0pxqh8zcms | Further attacks were reported later in some parts of Transcaucasia, particularly in 1908. Instances are known in Azerbaijan of striped hyenas killing children sleeping in courtyards during the 1930s and 1940s. In 1942, a guard sleeping in his hut was mauled by a hyena in Golyndzhakh. | Striped hyena |
c_h0ry65e0v45x | Cases of children being taken by hyenas by night are known in southeast Turkmenia's Bathyz Nature Reserve. A further attack on a child was reported around Serakhs in 1948. Several attacks have occurred in India; in 1962, nine children were thought to have been taken by hyenas in the town of Bhagalpur in the Bihar State... | Striped hyena |
c_572oh283e9t0 | A census on wild animal attacks during a five-year period in the Indian state of Madhya Pradesh showed that hyenas had only attacked three people, the lowest figure when compared to deaths caused by wolves, gaur, boar, elephants, tigers, leopards and sloth bears.Though attacks on live humans are rare, striped hyenas wi... | Striped hyena |
c_4wozghumyejp | In ordinary complex geometry, an almost complex structure is integrable to a complex structure if and only if the Lie bracket of two sections of the holomorphic subbundle is another section of the holomorphic subbundle. In generalized complex geometry one is not interested in vector fields, but rather in the formal sum... | Generalized complex manifold |
c_lo10gshg48t9 | In ordinary conversation, everything usually refers only to the totality of things relevant to the subject matter. When there is no expressed limitation, everything may refer to the universe, or the world. The universe is most commonly defined as everything that physically exists: the entirety of time, all forms of mat... | Everything |
c_1ead0rl46k2e | According to some speculations, this universe may be one of many disconnected universes, which are collectively denoted as the multiverse. In the bubble universe theory, there are an infinite variety of universes, each with different physical constants. In the many-worlds hypothesis, new universes are spawned with ever... | Everything |
c_5a2e67itopyq | By definition, these speculations cannot currently be tested experimentally, yet, if multiple universes do exist, they would still be part of everything. Especially in a metaphysical context, World may refer to everything that constitutes reality and the universe: see World (philosophy). However, world may only refer t... | Everything |
c_s0lv5drvk9gk | In ordinary incandescent lamps, evaporated tungsten mostly deposits onto the inner surface of the bulb, causing the bulb to blacken and the filament to grow increasingly weak until it eventually breaks. The presence of the halogen, however, sets up a reversible chemical reaction cycle with this evaporated tungsten. The... | Halogen bulbs |
c_l5vg9oxq89hj | At some point, however, it will reach higher temperature regions within the bulb where it then dissociates, releasing tungsten back onto the filament and freeing the halogen to repeat the process. However, the overall bulb envelope temperature must be significantly higher than in conventional incandescent lamps for thi... | Halogen bulbs |
c_nbbvv3vp280v | Since quartz is very strong, the gas pressure can be higher, which reduces the rate of evaporation of the filament, permitting it to run a higher temperature (and so luminous efficacy) for the same average life. The tungsten released in hotter regions does not generally redeposit where it came from, so the hotter parts... | Halogen bulbs |
c_oeibjc4u2cfh | Quite soon, bromine was found to have advantages, but was not used in elemental form. Certain hydrocarbon bromine compounds gave good results. | Halogen bulbs |
c_2fbruexfmpja | Regeneration of the filament is also possible with fluorine, but its chemical reactivity is so great that other parts of the lamp are attacked. The halogen is normally mixed with a noble gas, often krypton or xenon. The first lamps used only tungsten for filament supports, but some designs use molybdenum – an example b... | Halogen bulbs |
c_z0yijn8v1gjg | For a fixed power and life, the luminous efficacy of all incandescent lamps is greatest at a particular design voltage. Halogen lamps made for 12 to 24 volt operation have good light outputs, and the very compact filaments are particularly beneficial for optical control (see picture). The ranges of multifaceted reflect... | Halogen bulbs |
c_kltit4vhcnh1 | In ordinary language, a crime is an unlawful act punishable by a state or other authority. The term crime does not, in modern criminal law, have any simple and universally accepted definition, though statutory definitions have been provided for certain purposes. The most popular view is that crime is a category created... | Illegal activity |
c_awnx8msyo0b2 | Such acts are forbidden and punishable by law.The notion that acts such as murder, rape, and theft are to be prohibited exists worldwide. What precisely is a criminal offence is defined by the criminal law of each relevant jurisdiction. While many have a catalogue of crimes called the criminal code, in some common law ... | Illegal activity |
c_1a915oebhw6j | The state (government) has the power to severely restrict one's liberty for committing a crime. In modern societies, there are procedures to which investigations and trials must adhere. If found guilty, an offender may be sentenced to a form of reparation such as a community sentence, or, depending on the nature of the... | Illegal activity |
c_msaatr07th61 | In ordinary language, an average is a single number taken as representative of a list of numbers, usually the sum of the numbers divided by how many numbers are in the list (the arithmetic mean). For example, the average of the numbers 2, 3, 4, 7, and 9 (summing to 25) is 5. Depending on the context, an average might b... | Average value |
c_aihn1rw6sfxg | In ordinary materials, the magnetic dipole moments of individual atoms produce magnetic fields that cancel one another, because each dipole points in a random direction, with the overall average being very near zero. Ferromagnetic materials below their Curie temperature, however, exhibit magnetic domains in which the a... | Quantum spin |
c_ni6lxdlfb4px | In diamagnetic materials, on the other hand, the magnetic dipole moments of individual atoms align oppositely to any externally applied magnetic field, even if it requires energy to do so. The study of the behavior of such "spin models" is a thriving area of research in condensed matter physics. For instance, the Ising... | Quantum spin |
c_vcun3e0rdyjk | In ordinary materials, the magnetic dipole moments of individual atoms produce magnetic fields that cancel one another, because each dipole points in a random direction. Ferromagnetic materials below their Curie temperature, however, exhibit magnetic domains in which the atomic dipole moments are locally aligned, produ... | Quantum magnetism |
c_fbs7qse3v9f1 | For instance, the Ising model describes spins (dipoles) that have only two possible states, up and down, whereas in the Heisenberg model the spin vector is allowed to point in any direction. In certain magnets, the magnetic dipoles are only free to rotate in a 2D plane, a system which can be adequately described by the... | Quantum magnetism |
c_zb4ynr6cymau | In ordinary metals, interatomic distances are nearly constant through a wide range of temperatures and pressures; this is not the case with Rydberg matter, whose distances and thus properties vary greatly with excitations. A key variable in determining these properties is the principal quantum number n that can be any ... | Rydberg matter |
c_l10z6fuujeg1 | In ordinary polygonal billiards, the existence of periodic orbits is a major unsolved problem. For instance, it is unknown if every triangular shaped table has a periodic billiard path. More progress has been made for outer billiards, though the situation is far from well understood. As mentioned above, all the orbits ... | Outer billiards |
c_7z97erhdsau5 | In ordinary representation theory, every indecomposable module is irreducible, and so every module is projective. However, the simple modules with characteristic dividing the group order are rarely projective. Indeed, if a simple module is projective, then it is the only simple module in its block, which is then isomor... | Defect zero |
c_0xpo3zaja1ss | Generally, the structure of projective modules is difficult to determine. For the group algebra of a finite group, the (isomorphism types of) projective indecomposable modules are in a one-to-one correspondence with the (isomorphism types of) simple modules: the socle of each projective indecomposable is simple (and is... | Defect zero |
c_pv181qzftl59 | Each projective indecomposable module (and hence each projective module) in positive characteristic p may be lifted to a module in characteristic 0. Using the ring R as above, with residue field K, the identity element of G may be decomposed as a sum of mutually orthogonal primitive idempotents (not necessarily central... | Defect zero |
c_n8u1goo8kpev | In ordinary representation theory, the number of simple modules k(G) is equal to the number of conjugacy classes of G. In the modular case, the number l(G) of simple modules is equal to the number of conjugacy classes whose elements have order coprime to the relevant prime p, the so-called p-regular classes. | Modular representation |
c_6e50ssu0ul2v | In ordinary use, only the oscillator in the dip meter is powered, and the circuit under test's only power is what it drains from the signal in the GDO coil. When both circuits are resonant at the same frequency, power transfer from the coil to the adjacent tested circuit reaches a maximum, consequently the dip meter's ... | Dip meter |
c_nfazxuwsv1hc | In ordеr to storе and rеtriеvе thе data nееdеd for procеssing, AI rеquirеs еffеctivе mеmory systеms. To avoid bottlеnеcks in data accеss, rapid connеctivity and largе-capacity mеmory is crucial. | Hardware for artificial intelligence |
c_t8z2geq1zi3m | In organ performance, block harmony means that close position chords are added below the melody in the right hand, and the left hand doubles the melody an octave lower, while in open harmony the middle note of the chord is played an octave lower creating an "open" space in the chord. | Close and open harmony |
c_855eyg2v5fpp | In organ trios, the lower octaves of a Hammond organ or electronic keyboard are used as a substitute for bass guitar or double bass. The organist can play the bassline using the bass pedal keyboard or using the lower manual. As well, the organist could play right-hand chords and melodies. Organ trios were a widely used... | Rhythm section |
c_ft8ygzkwpli8 | Organ trios are sometimes used in rock as well. The Doors' keyboardist Ray Manzarek used a keyboard bass to play the bass lines. Manzarek, guitarist Robby Krieger, and drummer John Densmore would act as an organ trio with the addition of singer Jim Morrison. | Rhythm section |
c_sf108gjiy2dw | In organic (and inorganic) chemistry, nucleophilic substitution is a fundamental class of reactions in which a nucleophile selectively bonds with or attacks the positive or partially positive charge on an atom or a group of atoms. As it does so, it replaces a weaker nucleophile, which then becomes a leaving group; the ... | Aromatic substitution |
c_2i1w53iddpsq | The prior state of charge is restored when the leaving group (LG) departs with an electron pair. The principal product in this case is R−Nuc. In such reactions, the nucleophile is usually electrically neutral or negatively charged, whereas the substrate is typically neutral or positively charged. An example of nucleoph... | Aromatic substitution |
c_ydu4s7i7d7i2 | In organic and inorganic hybrid systems such as Organic-Inorganic Hybrid Perovskite and Metal–Organic Frameworks (MOFs), the organic–inorganic interface is a critical parameter that controls the performance of light-harvesting devices. Lead-halide perovskite materials demonstrate exceptional photophysical properties an... | Light Harvesting Materials |
c_vny0wk4q37ij | MOFs may also be functionalized through surface modification with quantum dots, or through the embedding of photosensitive ruthenium or osmium metal complexes into the MOF structure.Inorganic materials such as silicon nanostructures, inorganic oxide films (e.g. titanium oxide and indium oxide), and ultrathin two-dimens... | Light Harvesting Materials |
c_u3smpoz2ky2v | Silicon is highly abundant, has extensive charge carrier mobility and high stability, allowing it to be widely used in photovoltaic and semiconductor applications. Currently the most efficient single junction device employing silicon has reached a solar conversion efficiency as high as 29.1%. Silicon nanostructures suc... | Light Harvesting Materials |
c_v3fvgoq8b4jw | Silicon nanostructures also allow for the quantum confinement effect which can improve light absorption ranges and light-induced responses.Dye-sensitized solar cells frequently incorporate titanium dioxide as a principal component because it imparts sensitizer adsorption as well as charge separation and electron transp... | Light Harvesting Materials |
c_k5zrqd3aeexk | In organic and organometallic chemistry, an organyl group is an organic substituent with one (sometimes more) free valence(-s) at a carbon atom. The term is often used in chemical patent literature to protect claims over a broad scope. | Organyl group |
c_b50ef3jxb3bp | In organic carboxylic acids, an electronegative substituent can pull electron density out of an acidic bond through the inductive effect, resulting in a smaller p K a {\displaystyle \mathrm {p} K_{{\ce {a}}}} value. The effect decreases, the further the electronegative element is from the carboxylate group, as illustra... | Strong acids |
c_vqxrgzwuu0pe | In organic chemistry a carbonate can also refer to a functional group within a larger molecule that contains a carbon atom bound to three oxygen atoms, one of which is double bonded. These compounds are also known as organocarbonates or carbonate esters, and have the general formula ROCOOR′, or RR′CO3. Important organo... | (CO3)2- |
c_vf0fdyq4nho8 | In organic chemistry a halohydrin (also a haloalcohol or β-halo alcohol) is a functional group in which a halogen and a hydroxyl are bonded to adjacent carbon atoms, which otherwise bear only hydrogen or hydrocarbyl groups (e.g. 2-chloroethanol, 3-chloropropane-1,2-diol). The term only applies to saturated motifs, as s... | Halohydrin |
c_wyi17yqs0lh9 | In organic chemistry a hydroxy ketone (often referred to simply as a ketol) is a functional group consisting of a ketone flanked by a hydroxyl group. Chemicals in this group can be classified by the position of the hydroxyl relative to the ketone. The two main classes have the hydroxyl on the alpha or beta carbon, that... | Hydroxy ketone |
c_hxpjqt1kcjcl | They are commonly formed by condensation or reductive coupling of two carbonyl compounds or oxidation of ketones. The simplest such compound is hydroxyacetone. If the alcohol is primary, alpha-hydroxy ketones give a positive Fehling's test. | Hydroxy ketone |
c_nsgl1vqbs2xt | Beta-hydroxy ketones are a type of aldol. They are commonly formed by an aldol reaction between two carbonyl compounds. A simple example is diacetone alcohol. | Hydroxy ketone |
c_vha16nna3c8r | In organic chemistry a methylthiomethyl (MTM) ether is a protective group for hydroxyl groups. Hydroxyl groups are present in many chemical compounds and they must be protected during oxidation, acylation, halogenation, dehydration and other reactions to which they are susceptible. Many kinds of protective groups for h... | Methylthiomethyl ether |
c_e4lgjp5lc6am | To introduce an MTM ether to a hydroxyl group, two methods are mainly used. One is a typical Williamson ether synthesis using an MTM halide as an MTM resource and sodium hydride (NaH) as a base. The other is a special method, in which dimethyl sulfoxide (DMSO) and acetic anhydride (Ac2O) are used. | Methylthiomethyl ether |
c_53o46eimap8c | In this case, the reaction proceeds with Pummerer rearrangement: MTM ethers have another advantage. They are removed by neutral (but toxic) mercuric chloride, to which most other ethers are stable. As a result, the selective deprotection of polyfunctional molecules becomes possible using MTM ethers as the protective gr... | Methylthiomethyl ether |
c_kqr2pue6a6ax | In organic chemistry an enol ether is an alkene with an alkoxy substituent. The general structure is R2C=CR-OR where R = H, alkyl or aryl. A common subfamily of enol ethers are vinyl ethers, with the formula ROCH=CH2. Important enol ethers include the reagent 3,4-dihydropyran and the monomers methyl vinyl ether and eth... | Enol ether |
c_dkbnm4a6p84o | In organic chemistry and biochemistry it is customary to use pKa values for acid dissociation equilibria. p K a = − log K d i s s = log ( 1 K d i s s ) {\displaystyle \mathrm {p} K_{\mathrm {a} }=-\log K_{\mathrm {diss} }=\log \left({\frac {1}{K_{\mathrm {diss} }}}\right)\,} where log denotes a logarithm to base 10... | Equilibrium constants |
c_clb7tmwo1x7c | For any given acid or base the two constants are related by pKa + pKb = pKw, so pKa can always be used in calculations. On the other hand, stability constants for metal complexes, and binding constants for host–guest complexes are generally expressed as association constants. When considering equilibria such as M + HL ... | Equilibrium constants |
c_y870kk6cdq1x | In organic chemistry and biochemistry, a side chain is a chemical group that is attached to a core part of the molecule called the "main chain" or backbone. The side chain is a hydrocarbon branching element of a molecule that is attached to a larger hydrocarbon backbone. It is one factor in determining a molecule's pro... | Side chain |
c_k7jeww5hr66p | In organic chemistry annulation (from the Latin anellus for "little ring"; occasionally annelation) is a chemical reaction in which a new ring is constructed on a molecule. Examples are the Robinson annulation, Danheiser annulation and certain cycloadditions. Annular molecules are constructed from side-on condensed cyc... | Fused-ring compound |
c_c3600id1w1i1 | In organic chemistry convention, formal charges are an essential feature of a correctly rendered Lewis–Kekulé structure, and a structure omitting nonzero formal charges is considered incorrect, or at least, incomplete. In contrast, this convention is not followed in inorganic chemistry. Formal charges are drawn in clos... | Valence charge |
c_fp8ndfqego3h | They may or may not be enclosed in a circle for clarity. On the other hand, many workers in organometallic and a majority of workers in coordination chemistry will omit formal charges, unless they are needed for emphasis, or they are needed to make a particular point. Instead a top-right corner ⌝ will be drawn followin... | Valence charge |
c_oznzpz9ru5gk | In organic chemistry glycerolysis refers to any process in which chemical bonds are broken via a reaction with glycerol. The term refers almost exclusively to the transesterification reaction of glycerol with triglycerides (fats/oils) to form mixtures of monoglycerides and diglycerides. These find a variety of uses; as... | Glycerolysis |
c_n1s4yjmp2b5y | In organic chemistry sulfamation is the installation of either of two related functional groups, sulfamic acid (R2NSO3H) and sulfamate (R2NSO3−). Typical methods entail reaction of primary amines with sources of sulfur trioxide such as pyridine-sulfur trioxide: RNH2 + SO3 → RNHSO3HSulfamation can also be effected by tr... | Sulfamation |
c_l6v5j56oqnl7 | In organic chemistry the Brook rearrangement refers to any carbon to oxygen silyl migration. The rearrangement was first observed in the late 1950s by Canadian chemist Adrian Gibbs Brook (1924–2013), after which the reaction is named. These migrations can be promoted in a number of different ways, including thermally,... | Brook rearrangement |
c_6qeku58b5vf6 | In the forward direction, these silyl migrations produce silyl ethers as products which is driven by the stability of the oxygen-silicon bond. The silyl substituents can be aliphatic or aromatic, and if the silicon is a center of chirality, the migration occurs with retention at this center. This migration occurs throu... | Brook rearrangement |
c_1cjj5ww1ifh6 | In organic chemistry the Hoch-Campbell ethylenimine synthesis is a method for constructing ethyleneimines from oximes. The oxime is treated with Grignard reagents: == References == | Hoch-Campbell ethylenimine synthesis |
c_dnu5vl8eehh1 | In organic chemistry the addition of the prefix benzo to the name of a chemical compound indicates the addition of an even number of carbon atoms to an unsaturated or already aromatic compound by which a new aromatic ring is formed. Between the prefix benzo and the name of the parent compound then place of the addition... | List of benzo compounds |
c_zpoobwizi9c0 | In organic chemistry, "sodium bisulfite" is used to form adducts with aldehyde and with certain cyclic ketones. These adducts are α-hydroxysulfonic acids. This reaction is useful for the separation and purification of aldehydes. The bisulfite adducts are charged and so are more soluble in polar solvents. | Hydrogen sulfite ion |
c_ryx10ms0npoc | The reaction can be reversed in base or strong acid. Examples of such procedures are described for benzaldehyde, 2-tetralone, citral, the ethyl ester of pyruvic acid and glyoxal. In the ring-expansion reaction of cyclohexanone with diazald, the bisulfite reaction is reported to allow differentiation between the primary... | Hydrogen sulfite ion |
c_t19m2dkz2u5f | Sodium bisulfite is a decoloration agent in purification procedures because it reduces strongly coloured oxidizing agents, conjugated alkenes and carbonyl compounds. Bisulfite is also the key ingredient in the Bucherer reaction. In this reaction an aromatic hydroxyl group is converted to the corresponding amine group. | Hydrogen sulfite ion |
c_ipvdd1l8n1ip | This is a reversible reaction. The first step in this reaction is an addition reaction of sodium bisulfite to an aromatic double bond. The Bucherer carbazole synthesis is a related organic reaction that uses sodium bisulfite as a reagent. | Hydrogen sulfite ion |
c_yknbl69cl3tv | In organic chemistry, "sulfide" usually refers to the linkage C–S–C, although the term thioether is less ambiguous. For example, the thioether dimethyl sulfide is CH3–S–CH3. Polyphenylene sulfide (see below) has the empirical formula C6H4S. | Sulfide |
c_vcs4l515bxck | Occasionally, the term sulfide refers to molecules containing the –SH functional group. For example, methyl sulfide can mean CH3–SH. The preferred descriptor for such SH-containing compounds is thiol or mercaptan, i.e. methanethiol, or methyl mercaptan. | Sulfide |
c_t34oeg2c43gx | In organic chemistry, 1-propenyl (or simply propenyl) has the formula CH=CHCH3 and 2-propenyl (isopropenyl) has the formula CH2=C-CH3. These groups are found in many compounds. Propenyl compounds are isomeric with allyl compounds, which have the formula CH2-CH=CH2. | Propenyl |
c_jjse0zwq17bc | In organic chemistry, 1β-Methylseleno-N-acetyl-D-galactosamine is an amino sugar containing selenium. It is found in urine, as a disposal metabolite for selenium. | 1β-Methylseleno-N-acetyl-D-galactosamine |
c_qw7rf4xc6769 | In organic chemistry, AD-mix is a commercially available mixture of reagents that acts as an asymmetric catalyst for various chemical reactions, including the Sharpless asymmetric dihydroxylation of alkenes. The two letters AD, stand for asymmetric dihydroxylation. The mix is available in two variations, "AD-mix α" and... | AD-mix |
c_4c6cnq250uq8 | In organic chemistry, Arnold studied the determination of chlorides, urea, uric acid, phosphates, alkaloids and sugar under physiological conditions. Many of these substances were part of the composition of urine, and could be useful in assessing both normal body function and disease. He also studied disinfectants incl... | Karl Arnold (chemist) |
c_lesg515kpmuw | He also studied the hygiene of milk and food ingredients and tested air quality in stables.He published extensively on chemical analysis, veterinary medicine, and medicine. His Repetitorium der Chemie ("Chemistry Revision Course") was a standard work for veterinarians, medical students and pharmacists. Reprinted sixtee... | Karl Arnold (chemist) |
c_9ex4mvves1qj | In organic chemistry, Bredt's rule is an empirical observation that states that a double bond cannot be placed at the bridgehead of a bridged ring system, unless the rings are large enough. The rule is named after Julius Bredt, who first discussed it in 1902 and codified it in 1924. It primarily relates to bridgeheads ... | Bredt's rule |
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