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Tert-Amyl Methyl Ether
''tert''-Amyl methyl ether (TAME) is an ether used as a fuel oxygenate. TAME derives from C5 distillation fractions of naphtha. It has an ethereous odor. Unlike most ethers, it does not require a stabilizer as it does not form peroxides on storage. Other names: * 2-Methoxy-2-methylbutane * Butane, 2-methoxy-2-methyl- * 1,1-Dimethylpropyl methyl ether * Methyl tert-pentyl ether * Methyl tert-Amyl ether * 2-Methyl-2-methoxybutane * Methyl 2-methyl-2-butyl ether * tert-Pentyl methyl ether * Tertiary amyl methyl ether * Methyl 1,1-dimethylpropyl ether * 2-Methoxy-2-methylbutane Uses TAME is mostly used as an oxygenate to gasoline. It is added for three reasons: to increase octane enhancement, to replace banned tetraethyl lead, and to raise the oxygen content in gasoline. It is known that TAME in fuel reduces exhaust emissions of some volatile organic compounds. TAME is also used as a solvent in organic synthesis as a more environmentally friendly alternative to some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma-Aldrich
Sigma-Aldrich (formally MilliporeSigma) is an American chemical, life science, and biotechnology company owned by the multinational chemical conglomerate Merck Group. Sigma-Aldrich was created in 1975 by the merger of Sigma Chemical Company and Aldrich Chemical Company. It grew through various acquisitions until it had over 9,600 employees and was listed on the Fortune 1000. The company has two United States headquarters, in St. Louis and Burlington, MA and has operations in approximately 40 countries. In 2015, the multinational chemical conglomerate Merck Group acquired Sigma-Aldrich for $17 billion. The company is currently a part of Merck's life science business and in combination with Merck's earlier acquired Millipore Corporation, Millipore, operates as MilliporeSigma. It is headquartered in Burlington, Massachusetts, United States. History Sigma Chemical Company of St. Louis and Aldrich Chemical Company of Milwaukee were both American specialty chemical companies when they ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suzuki Reaction
The Suzuki reaction or Suzuki coupling is an organic reaction that uses a palladium complex catalyst to cross-couple a boronic acid to an organohalide. It was first published in 1979 by Akira Suzuki, and he shared the 2010 Nobel Prize in Chemistry with Richard F. Heck and Ei-ichi Negishi for their contribution to the discovery and development of noble metal catalysis in organic synthesis. This reaction is sometimes telescoped with the related Miyaura borylation; the combination is the Suzuki–Miyaura reaction. It is widely used to synthesize poly olefins, styrenes, and substituted biphenyls. The general scheme for the Suzuki reaction is shown below, where a carbon–carbon single bond is formed by coupling a halide (R1-X) with an organoboron species (R2-BY2) using a palladium catalyst and a base. The organoboron species is usually synthesized by hydroboration or carboboration, allowing for rapid generation of molecular complexity. Several reviews have been publ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dialkyl Ethers
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List Of Gasoline Additives
Gasoline additives may increase gasoline's octane rating, thus allowing the use of higher compression ratios for greater efficiency and power, or act as corrosion inhibitors or lubricants. Other additives include metal deactivators, oxygenates and antioxidants. Some additives are harmful and are regulated or banned in some countries. Fictional additives *Sugar, as seen in ''The Passionate Stranger'' (1957) and List of common misconceptions, popularly believed to damage the engine. Additives *Oxygenates ** Alcohol (chemistry), Alcohols: *** Methanol (MeOH) *** Ethanol (EtOH); see also common ethanol fuel mixtures *** Isopropyl alcohol (IPA) *** n-Butanol, ''n''-butanol (BuOH) *** Gasoline grade tert-Butanol, ''t''-butanol (GTBA) ** Ethers: *** Methyl tert-butyl ether (MTBE), now outlawed in many states of the United States, U.S. for road use because of Methyl tert-butyl ether controversy, water contamination. *** Tertiary amyl methyl ether (TAME) *** Tertiary hexyl methyl ether (TH ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethyl Tert-butyl Ether
Ethyl ''tertiary''-butyl ether (ETBE), also known as ethyl ''tert''-butyl ether, is commonly used as an oxygenate gasoline additive in the production of gasoline from crude oil. ETBE offers equal or greater air quality benefits than ethanol, while being technically and logistically less challenging. Unlike ethanol, ETBE does not induce evaporation of gasoline, which is one of the causes of smog, and does not absorb moisture from the atmosphere. Production Ethyl tert-butyl ether is manufactured industrially by the acidic etherification of isobutylene with ethanol at a temperature of 30–110 °C and a pressure of 0,8–1,3 MPa. The reaction is carried out with an acidic ion-exchange resin as a catalyst. Suitable reactors are fixed-bed reactors such as tube bundle or circulation reactors in which the reflux can be cooled optionally. Ethanol, produced by fermentation and distillation, is more expensive than methanol, which is derived from natural gas. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Tert-butyl Ether
Methyl ''tert''-butyl ether (MTBE), also known as ''tert''-butyl methyl ether, is an organic compound with a structural formula (CH3)3COCH3. MTBE is a volatile, flammable, and colorless liquid that is sparingly soluble in water. Primarily used as a fuel additive, MTBE is blended into gasoline to increase its octane rating and knock resistance, and reduce unwanted emissions. Production and properties MTBE is manufactured via the chemical reaction of methanol and isobutylene. Methanol is primarily derived from natural gas, where steam reforming converts the various light hydrocarbons in natural gas (primarily methane) into carbon monoxide and hydrogen. The resulting gases then further react in the presence of a catalyst to form methanol. Isobutylene can be produced through a variety of methods. ''n''-butane can be isomerized into isobutane which can be dehydrogenated to isobutylene. In the Halcon process, ''t''-Butyl hydroperoxide derived from isobutane oxygenation is tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kovats Retention Index
In gas chromatography, the Kovats retention index (shorter Kovats index, retention index; plural retention indices) is used to convert retention times into system-independent constants. The index is named after the Hungarian-born Swiss chemist Ervin Kováts (1927-2012), who outlined the concept in the 1950s while performing research into the composition of the essential oils. The retention index of a chemical compound is retention time interpolated between adjacent ''n''-alkanes. While retention times vary with the individual chromatographic system (e.g. with regards to column length, film thickness, diameter and inlet pressure), the derived retention indices are quite independent of these parameters and allow comparing values measured by different analytical laboratories under varying conditions and analysis times from seconds to hours. Tables of retention indices are used to identify peaks by comparing measured retention indices with the tabulated values. Isothermal Kovats ret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxicology Letters
''Toxicology Letters'' is a peer-reviewed scientific journal for the rapid publication of short reports on all aspects of toxicology, especially mechanisms of toxicity. Toxicology Letters is the official journal of Eurotox.Website of Toxicology Letters at Elsevier accessed on March, 9th, 2013. ''(Eurotox exists as a Society within the meaning of Art. 60 et seq. of the . The registered address of Eurotox is in .)'' Editors-in-chief are Wolfgang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOAEL
The no-observed-adverse-effect level (NOAEL) denotes the level of exposure of an organism, found by experiment or observation, at which there is no biologically or statistically significant increase in the frequency or severity of any adverse effects of the tested protocol. In drug development, the NOAEL of a new drug is assessed in laboratory animals, such as mice, prior to initiation of human trials in order to establish a safe clinical starting dose in humans. The OECD publishes guidelines for Preclinical Safety Assessments, in order to help scientists discover the NOAEL. Synopsis Some adverse effects in the exposed population when compared to its appropriate control might include alteration of morphology, functional capacity, growth, development or life span. The NOAEL is determined or proposed by qualified personnel, often a pharmacologist or a toxicologist. The NOAEL could be defined as "the highest experimental point that is without adverse effect," meaning that under l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Observational Battery
Functional may refer to: * Movements in architecture: ** Functionalism (architecture) ** Form follows function * Functional group, combination of atoms within molecules * Medical conditions without currently visible organic basis: ** Functional symptom ** Functional disorder * Functional classification for roads * Functional organization * Functional training In mathematics * Functional (mathematics), a term applied to certain scalar-valued functions in mathematics and computer science ** Minnesota functionals ** Functional analysis, a branch of mathematical analysis ** Linear functional, a type of functional often simply called a functional in the context of functional analysis * Higher-order function, also called a functional, a function that takes other functions as arguments In computer science, software engineering * "Functional" (noun) may be used as a synonym for Higher-order function * (C++), a header file in the C++ Standard Library * Functional design, a paradig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System Depression
Central nervous system depression (or CNS depression) is a nervous system disorder characterized by a severely impaired physiological state in which patients may exhibit decreased rate of breathing, decreased heart rate, and loss of consciousness; in extreme cases, CNS depression can possibly lead to coma or death. Causes Central nervous system depression is generally caused by the improper or excessive use of depressant drugs such as opioids, barbiturates, benzodiazepines, general anesthetics, anticonvulsants, and certain sleep medications. These drugs, although useful for treating severe cases of depression that may manifest as CNS depression, can easily be misused. The medications above depress the functions of the spinal cord and brain, both vital components of the central nervous system. In cases of misuse due to addiction, accidents, or unregulated dosage increases, individuals can very easily slip into unconscious coma states because neural activity drops below sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
