Natural and synthetic

Hydrogen peroxide in aqueous solution has many uses, because the products from its reaction are either water or oxygen, which are generally innocuous. The chief use is bleaching of textiles, both natural and synthetic, and of wood pulp for paper. Other uses are the oxidation of dyestuffs, in photography and in the production of... 

Chloric(III) acid is a fairly weak acid, and is an oxidising agent, for example it oxidises aqueous iodide ion to iodine. Sodium chlorate(III) (prepared as above) is used commercially as a mild bleaching agent it bleaches many natural and synthetic fibres without degrading them, and will also bleach, for example, oils, varnishes and beeswax. 

Laser desorption methods are particularly useful for substances of high mass such as natural and synthetic polymers. Glycosides, proteins, large peptides, enzymes, paints, ceramics, bone, and large... 

Laser desorption is particularly good for producing ions from analytically difficult materials. For example, lasers can be used with bone, ceramics, high-molecular-mass natural and synthetic polymers, and rock or metal specimens. Generally, few fragment ions are formed. 

Rubber. Both natural and synthetic rubber are used as bonding agents for abrasive wheels. Rubber-bond wheels are ideal for thin cut-off and slicing wheels and centerless grinding feed wheels. They are more flexible and more water-resistant than resinoid wheels. 

Natural and synthetic soda ash capacity is shown ia Table 4. As iadicated ia Table 5, eight companies represent about 75% of the Western wodd s soda ash capacity. 

Vitamins. The preparation of heat-sensitive natural and synthetic vitamins (qv) involves solvent extraction. Natural vitamins A and D are extracted from fish Hver oils and vitamin E from vegetable oils (qv) Hquid propane [74-98-6] is the solvent. In the synthetic processes for vitamins A, B, C, and E, solvent extraction is generally used either in the separation steps for intermediates or in the final purification. 

The physical properties of these fibers are compared with those of natural fibers and other synthetic fibers in Table 1. Additional property data may be found in compilations of the properties of natural and synthetic fibers (1). Apart from the polyolefins, acryhcs and nylon fibers are the lightest weight fibers on the market. Modacryhcs are considerably more dense than acryhcs, with a density about the same as wool and polyester. 

General schemes for the identification of natural and synthetic fibers have been estabhshed by the Textile Institute and by the American Association of Textile Chemists and Colorists (8). A comprehensive treatment of burning, solvent, staining, microscopy, and density techniques has been given (9) and a general discussion of procedures for identifyiag synthetic fibers has been presented (10). 

Searching a crime scene is a complex process (25), involving poHce, crime scene technicians, and forensic scientists. The procedure requires careful documentation, collection, and preservation of the evidence. Trace evidence (26) in criminal investigations typically consists of hairs (27,28) both natural and synthetic fibers (qv) (29,30), fabrics glass (qv) (31,32) plastics (33) sod plant material budding material such as cement (qv), paint (qv), stucco, wood (qv), etc (34), flammable fluid residues (35,36), eg, in arson investigations explosive residues, eg, from bombings (37,38) (see Explosives and propellents), and so on. 

Od-in-water based hairdressings offer good spreading characteristics, have a less greasy feel, and are more easdy rinsed than water-in-od forms. Mineral od is found in these products, although natural and synthetic ods have been used. The typical od-in-water emulsifiers are used in preparing these emulsions. 

HoUow fibers can be prepared from almost any spiunable material. The fiber can be spun directly as a membrane or as a substrate which is post-treated to achieve desired membrane characteristics. Analogous fibers have been spun in the textile industry and are employed for the production of high bulk, low density fabrics. The technology employed in the fabrication of synthetic fibers appUes also to the spinning of hoUow-fiber membranes from natural and synthetic polymers. 

Terpene resins, because of their low odor and acceptable FDA clearance, are used as tackifiers for the natural and synthetic gum bases used in chewing gum. Selected petroleum resins are also used as gum bases. 

Many natural and synthetic organic compounds are hydroxy dicarboxyhc acids (see also Hydroxycarboxylic acids). This article discusses mainly malic and tartaric acids thiomalic acid is included because of its stmctural similarity to malic acid. 

Advances in immunology during the last part of the twentieth century have continued at a rapid rate and cytokines and immune cells having specific markers continue to be defined. A number of natural and synthetic immunotherapeutic agents have been discovered that can modulate components of the normal or aberrant immune system, through stimulation or suppression. However, most of these substances also have inherent adverse side effects. 

Engclopedia of Poljmer Science and Engineering Online John Wiley Sons, Inc. Dialog covers natural and synthetic polymeric materials... 

Latex technology encompasses coUoidal and polymer chemistry ia the preparation, processing, and conversion of natural and synthetic latices into useful products. 

P. G. Cook, Latex—Natural and Synthetic Reinhold Publishing Corp., New York, 1956. 

The most important compound of Mo (TV) is molybdenum disulfide [1317-33-5] M0S2 (21). The layered stmcture of M0S2 is reflected in the flat plate-like hexagonal gray-black crystaUites found in natural and synthetic samples. The stmcture consists of pairs of close-packed layers of sulfur which are echpsed with respect to each other. The close-packed sulfur surfaces are naturally hydrophobic, which faciUtates the extraction of M0S2 ore by flotation. 

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