Subject extraction

Lewis preferred distilled or rain water in making ink, but spring water containing calcareous salts is better adopted for the purpose. Some remarks on this subject, extracted from Napier, have been inserted in tho article Dyeing,.—See Vol. I., page 584. 

Several of the articles referenced in this entry clearly state that the subject extract is derived from the whole fruit of bitter orange (Calapai et al. 1999 Firenzuoli et al. 2005 Min et al. 2005), while numerous others do not specifically identify the part of the plant from which the extract is derived (Bouchard et al. 2005 Bui et al. 2006 Colker et al. 1999 Gurley et al. 2004 Hansen et al. 2006 Nykamp et al. 2004). Some of the latter articles, however, provide zhi shi, which is the pinyin name for the dried immature fruit of... 

In the compounding of rubber formulations, many types of additives are used, some of which, such as antiozonants, are not usually included in polymer formulations. One of the earliest and most comprehensive procedures for the examination of vulcanisates was published by Zijp [114] in 1956. He subjected extracts of the vulcanisates to various preliminary treatments after which the compounding ingredients or their residues were separated and identified using paper chromatography. Somewhat later, Gaczynski and Stephen [115] published a paper chromatographic method for the identification of the accelerators most commonly used in Poland at that time. 

By subjecting extracts of rabbit muscle to a series of ammonium sulfate fractionations, a cut was obtained which had a turnover number of about 1400 per minute per 10 g. of protein. Since the enzyme is imusually labile to acid conditions in all purification procedures the pH had to be held above 7. There is evidence that the stability of the enzyme is affected not only by the pH but also by the nature of the ionic environment and concentration. Thus, certain anions such as oxalate, pyrophosphate, phosphate, and sulfate tend to stabilize buffered solutions of the enzyme. ... 

The analogous procedure for a multivariate problem is to obtain many experimental equations like Eqs. (3-55) and to extract the best slopes from them by regression. Optimal solution for n unknowns requires that the slope vector be obtained from p equations, where p is larger than n, preferably much larger. When there are more than the minimum number of equations from which the slope vector is to be extracted, we say that the equation set is an overdetermined set. Clearly, n equations can be selected from among the p available equations, but this is precisely what we do not wish to do because we must subjectively discard some of the experimental data that may have been gained at considerable expense in time and money. 

Calcium Absorption. Phytates in cereal grains have also been reported to interfere with the absorption of calcium. However, a long-term study indicated a retention of calcium in subjects that consume large amounts of bread made with high extraction of flour (19). 

The component C in the separated extract from the stage contact shown in Eigure 1 may be separated from the solvent B by distillation (qv), evaporation (qv), or other means, allowing solvent B to be reused for further extraction. Alternatively, the extract can be subjected to back-extraction (stripping) with solvent A under different conditions, eg, a different temperature again, the stripped solvent B can be reused for further extraction. Solvent recovery (qv) is an important factor in the economics of industrial extraction processes. 

Extraction, a unit operation, is a complex and rapidly developing subject area (1,2). The chemistry of extraction and extractants has been comprehensively described (3,4). The main advantage of solvent extraction as an industrial process Hes in its versatiHty because of the enormous potential choice of solvents and extractants. The industrial appHcation of solvent extraction, including equipment design and operation, is a subject in itself (5). The fundamentals and technology of metal extraction processes have been described (6,7), as has the role of solvent extraction in relation to the overall development and feasibiHty of processes (8). The control of extraction columns has also been discussed (9). 

Lubricants. Petroleum lubricants continue to be the mainstay for automotive, industrial, and process lubricants. Synthetic oils are used extensively in industry and for jet engines they, of course, are made from hydrocarbons. Since the viscosity index (a measure of the viscosity behavior of a lubricant with change in temperature) of lube oil fractions from different cmdes may vary from +140 to as low as —300, additional refining steps are needed. To improve the viscosity index (VI), lube oil fractions are subjected to solvent extraction, solvent dewaxing, solvent deasphalting, and hydrogenation. Furthermore, automotive lube oils typically contain about 12—14% additives. These additives maybe oxidation inhibitors to prevent formation of gum and varnish, corrosion inhibitors, or detergent dispersants, and viscosity index improvers. The United States consumption of lubricants is shown in Table 7. 

Jasmin. "If the rose is the queen of flowers, the jasmin is the fairest and prettiest priacess. The two together reign supreme ia the world of flowers as well as ia the world of perfume" (12). As ia the case of rose, jasmin has been the subject of many iavestigations, and mote than 95 compounds have been identified to date ia extracts of Jasminum officinale L. vat. grandijlorum, the source of commercial jasmin ok, concrete, and absolute. The principal components ate shown ia Table 3 (13). 

Concretes and absolutes, both obtained by total extraction of the plant material and not subject to any form of distillation other than solvent removal, are complex mixtures containing many chemical types over wide molecular weight ranges. In some cases, gas chromatographic analysis shows httle volatile material. Yet these products have powerful odors and contribute in important ways to the perfumes in which they are used. 

The second principal advantage is that CYANEX 272 is the only one of the three above-mentioned compounds that extracts cobalt in preference to calcium (52). This property can minimise or eliminate the solvent losses that are associated with calcium extraction and the subsequent precipitation of gypsum cmds in the scmbbing or stripping circuits. This is illustrated in Eigure 1 where calcium extraction is shown as a function of pH for the three subject reagents. 

Solvent Extraction Technology. The use of solvent extraction technology to replace traditional processes has been the subject of considerable research and development effort since the 1970s (12,14—21). This newer technique was being used commercially as of 1995 in at least three of the principal refineries. 

Replacing one carbon atom of naphthalene with an a2omethene linkage creates the isomeric heterocycles 1- and 2-a2anaphthalene. Better known by their trivial names quinoline [91-22-5] (1) and isoquinoline [119-65-3] (2), these compounds have been the subject of extensive investigation since their extraction from coal tar in the nineteenth century. The variety of studies cover fields as diverse as molecular orbital theory and corrosion prevention. There is also a vast patent Hterature. The best assurance of continuing interest is the frequency with which quinoline and isoquinoline stmctures occur in alkaloids (qv) and pharmaceuticals (qv), for example, quinine [130-95-0] and morphine [57-27-2] (see Alkaloids). 

---