A gemstone is a piece of mineral crystal which, when cut or polished, is used to make jewelry or other adornments. However, certain rocks and occasionally organic materials that are not minerals are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity and notoriety are other characteristics that lend value to gemstones.
A synthetic element is one of 24 known chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called "synthetic", "artificial", or "man-made". The synthetic elements are those with atomic numbers 95–118, as shown in purple on the accompanying periodic table: these 24 elements were first created between 1944 and 2010. The mechanism for the creation of a synthetic element is to force additional protons into the nucleus of an element with an atomic number lower than 95. All known synthetic elements are unstable, but they decay at widely varying rates: the half-lives of their longest-lived isotopes range from microseconds to millions of years.
A synthetic radioisotope is a radionuclide that is not found in nature: no natural process or mechanism exists which produces it, or it is so unstable that it decays away in a very short period of time. Examples include technetium-95 and promethium-146. Many of these are found in, and harvested from, spent nuclear fuel assemblies. Some must be manufactured in particle accelerators.
Yarn is a long continuous length of interlocked fibres, used in sewing, crocheting, knitting, weaving, embroidery, ropemaking, and the production of textiles. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or other lubricants to withstand the stresses involved in sewing. Embroidery threads are yarns specifically designed for needlework. Yarn can be made of a number of natural or synthetic materials, and comes in a variety of colors and thicknesses. Although yarn may be dyed different colours, most yarns are solid coloured with a uniform hue.
Fiber or fibre is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate fibers, for example carbon fiber and ultra-high-molecular-weight polyethylene.
Synthetic fibers or synthetic fibres are fibers made by humans through chemical synthesis, as opposed to natural fibers that are directly derived from living organisms, such as plants or fur from animals. They are the result of extensive research by scientists to replicate naturally occurring animal and plant fibers. In general, synthetic fibers are created by extruding fiber-forming materials through spinnerets, forming a fiber. These are called synthetic or artificial fibers. The word polymer comes from a Greek prefix "poly" which means "many" and suffix "mer" which means "single units"..
Lab-grown diamond is diamond that is produced in a controlled technological process. Unlike diamond simulants, synthetic diamonds are composed of the same material as naturally formed diamonds—pure carbon crystallized in an isotropic 3D form—and share identical chemical and physical properties.
Synthetic oil is a lubricant consisting of chemical compounds that are artificially modified or synthesised. Synthetic lubricants can be manufactured using chemically modified petroleum components rather than whole crude oil, but can also be synthesized from other raw materials. The base material, however, is still overwhelmingly crude oil that is distilled and then modified physically and chemically. The actual synthesis process and composition of additives is generally a commercial trade secret and will vary among producers.
Synthetic biology (SynBio) is a multidisciplinary field of science that focuses on living systems and organisms, and it applies engineering principles to develop new biological parts, devices, and systems or to redesign existing systems found in nature.
A synthetic rubber is an artificial elastomer. They are polymers synthesized from petroleum byproducts. About 32 million metric tons of rubbers are produced annually in the United States, and of that amount two thirds are synthetic. Synthetic rubber, just like natural rubber, has many uses in the automotive industry for tires, door and window profiles, seals such as O-rings and gaskets, hoses, belts, matting, and flooring. They offer a different range of physical and chemical properties which can improve the reliability of a given product or application. Synthetic rubbers are superior to natural rubbers in two major respects: thermal stability, and resistance to oils and related compounds. They are more resistant to oxidizing agents, such as oxygen and ozone which can reduce the life of products like tires.
Synthetic fuel or synfuel is a liquid fuel, or sometimes gaseous fuel, obtained from syngas, a mixture of carbon monoxide and hydrogen, in which the syngas was derived from gasification of solid feedstocks such as coal or biomass or by reforming of natural gas.
ChemSpider is a freely accessible online database of chemicals owned by the Royal Society of Chemistry. It contains information on more than 100 million molecules from over 270 data sources, each of them receiving a unique identifier called ChemSpider Identifier.
Synthetic cannabinoids are a class of designer drug molecules that bind to the same receptors to which cannabinoids in cannabis plants attach. These novel psychoactive substances should not be confused with synthetic phytocannabinoids or synthetic endocannabinoids from which they are in many aspects distinct.
Sophora tonkinensis is a herb used in traditional Chinese medicine.
RCS-8 (also known as 1-(2-cyclohexylethyl)-3-(2-methoxyphenylacetyl)indole, SR-18, and BTM-8) is a synthetic cannabinoid that has been found as an ingredient of "herbal" synthetic cannabis blends. It can be described as an analogue of JWH-250 with the 1-pentyl group replaced by 1-(2-cyclohexylethyl), and can be expected to be less potent than JWH-250 (cf. JWH-007 and its cyclohexylethyl analogue). Despite not having been reported in the scientific or patent literature as yet, reputed recreational use of RCS-8 in the United States has led to it being specifically listed in a proposed 2011 amendment to the Controlled Substances Act, aiming to add a number of synthetic drugs into Schedule I. In addition, all CB1 receptor agonists of the 3-phenylacetylindole class such as RCS-8 are Schedule I Controlled Substances.
MAM-2201 is a drug that presumably acts as a potent agonist for the cannabinoid receptors. It had never previously been reported in the scientific or patent literature, and was first identified by laboratories in the Netherlands and Germany in June 2011 as an ingredient in synthetic cannabis smoking blends. Like RCS-4 and AB-001, MAM-2201 thus appears to be a novel compound invented by "research chemical" suppliers specifically for grey-market recreational use. Structurally, MAM-2201 is a hybrid of two known cannabinoid compounds JWH-122 and AM-2201, both of which had previously been used as active ingredients in synthetic cannabis blends before being banned in many countries.
EAM-2201 is a drug that presumably acts as a potent agonist for the cannabinoid receptors. It had never previously been reported in the scientific or patent literature, and was first identified by laboratories in Japan in July 2012 as an ingredient in synthetic cannabis smoking blends Like the closely related MAM-2201 which had been first reported around a year earlier, EAM-2201 thus appears to be another novel compound invented by designer drug suppliers specifically for recreational use. Structurally, EAM-2201 is a hybrid of two known cannabinoid compounds JWH-210 and AM-2201, both of which had previously been used as active ingredients in synthetic cannabis blends before being banned in many countries.
THJ-2201 is an indazole-based synthetic cannabinoid that presumably acts as a potent agonist of the CB1 receptor and has been sold online as a designer drug.
MDMB-CHMICA is an indole-based synthetic cannabinoid that is a potent agonist of the CB1 receptor and has been sold online as a designer drug. While MDMB-CHMICA was initially sold under the name "MMB-CHMINACA", the compound corresponding to this code name (i.e. the isopropyl instead of t-butyl analogue of MDMB-CHMINACA) has been identified on the designer drug market in 2015 as AMB-CHMINACA.
Synthetic MRI is a simulation method in Magnetic Resonance Imaging (MRI), for generating contrast weighted images based on measurement of tissue properties. The synthetic (simulated) images are generated after an MR study, from parametric maps of tissue properties. It is thereby possible to generate several contrast weightings from the same acquisition. This is different from conventional MRI, where the signal acquired from the tissue is used to generate an image directly, often generating only one contrast weighting per acquisition. The synthetic images are similar in appearance to those normally acquired with an MRI scanner.
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