Extraction influence

The tocopherol content of midseason orange oils followed the order Brown peel shaver (216 ppm), FMC in-line extractor (126 ppm) and screw press (104 ppm). The method of extraction influenced both the evaporation residue and the tocopherol content of orange oil, the higher the evaporation residue, the higher the tocopherol content. Since tocopherol is a good antioxidant,... 

Lee, J.H. Talcott, S.T. 2004. Fruit maturity and juice extraction influences ellagic acid derivatives and other antioxidant polyphenolics in muscadine grapes J. Agric. Food Chem. 52 361-366. 

Gascons VF, Souchon I, Athes V, and Martin M, Air stripping membrane contactor applied to aroma compounds extraction Influence of heat and water transfers on aroma transfer. Euromembrane 2004, Hamburg, Germany, September 28-October 1, 2004. 

Wheat protein fractions Symmetrical Size distribution of wheat protein fractions (albumins and globulins, gliadins, glutenins) prepared by extraction influence of oxidation on size distribution of high-MW glutenin [S. G. Stevenson, T. Ueno, and K. R. Preston, Anal. Chem. 71 8-14 (1999)]... 

Hemingway (1969) showed that in the high temperature drying of yellow birch veneer, fatty acids and other extractives influenced the wetting of veneers in a complex manner and showed that the observed effects were due to acetone extractives. 

Zbiral, J. (1992). Determination of molybdenum in hot water soil extracts influence of pH and available iron on the molybdenum content. Commun. Soil Sci Plant Anal. 23 817-25. 

M. Castellote, C. Andrade, C. Alonso, Electrochemical chloride extraction influence of testing conditions and mathematical modelling . Advances in Cement Research, 1999, 11, 63-80. 

Bracke E, Meijer A, Van Gelder B (2003) Venous occlusion of the access vein in patients referred for lead extraction influence of patient and lead characteristics. Pacing Clin Electrophysiol 26(8) 1649-1652... 

We studied the three electrodes using the DFT coupled with the NEGF scheme. To compare different electrode materials, we used a simple conjugated molecule, l,3,5-hexatriyne(which we will call alkyne for convenience s sake). Transmission calculations were made to extract influences solely from electrodes by modification of a molecular core and linkers. The band structure and surface density of states (SDOS) of each electrode material were compared to the transmission function of each system under a zero bias. 

First-Generation Copper Extractants Influence of Chemical Structure on pH Dependence of Copper Extraction... 

Pfaab, G., and Jork, H. (1994). Application of AMD for the determination of pesticides in drinking water. Part 3. Solid phase extraction influencing factors. Acta Hydrochim. Hydrobiol. 22 216—223. 

Ganhao, R., Morcuende, D. and Estevez, M. (2010). Protein oxidation in emulsified cooked burger patties with added fmit extracts Influence on color and texture deterioration during chill storage. Meat Science, 85,402-409. 

Additionally, Singleton et al. (1999) described that substances such as sugars or ascorbic acid present in the extracts influence results of various methods intended... 

P Munch, T Hofmann, P Schieberle. Comparison of key odorants generated by thermal treatment of commercial and self-prepared yeast extractions Influence of the amino acid composition on odorant formation. J Agric Food Chem 45 1338-1344, 1997. 

In spite of the importance of reaction prediction, only a few systems have been developed to tackle this problem, largely due to its complexity it demands a huge amount of work before a system is obtained that can make predictions of sufficient quality to be useful to a chemist. The most difficult task in the development of a system for the simulation of chemical reactions is the prediction of the course of chemical reactions. This can be achieved by using knowledge automatically extracted from reaction databases (see Section 10.3.1.2). Alternatively, explicit models of chemical reactivity will have to be included in a reaction simulation system. The modeling of chemical reactivity is a very complex task because so many factors can influence the course of a reaction (see Section 3.4). 

In summary, solvents can influence Diels-Alder reactions through a multitude of different interactions, of which the contributions to fire overall rate uniquely depend on the particular solvent-diene-dienophile combination. Scientists usually feel uncomfortable about such a situation and try to extract generalities. When limited to the most extensively studied type A Diels-Alder reactions this approach seems feasible. These Diels-Alder reactions are dominated by hydrogen bonding interactions in combination with solvophobic interactions. This observation predicts a very special role of water as a solvent for type A Diels-Alder reactions, which is described in Section 1.4. 

In a simple liquid-liquid extraction the solute is partitioned between two immiscible phases. In most cases one of the phases is aqueous, and the other phase is an organic solvent such as diethyl ether or chloroform. Because the phases are immiscible, they form two layers, with the denser phase on the bottom. The solute is initially present in one phase, but after extraction it is present in both phases. The efficiency of a liquid-liquid extraction is determined by the equilibrium constant for the solute s partitioning between the two phases. Extraction efficiency is also influenced by any secondary reactions involving the solute. Examples of secondary reactions include acid-base and complexation equilibria. 

Separation Processes. The product of ore digestion contains the rare earths in the same ratio as that in which they were originally present in the ore, with few exceptions, because of the similarity in chemical properties. The various processes for separating individual rare earth from naturally occurring rare-earth mixtures essentially utilize small differences in acidity resulting from the decrease in ionic radius from lanthanum to lutetium. The acidity differences influence the solubiUties of salts, the hydrolysis of cations, and the formation of complex species so as to allow separation by fractional crystallization, fractional precipitation, ion exchange, and solvent extraction. In addition, the existence of tetravalent and divalent species for cerium and europium, respectively, is useful because the chemical behavior of these ions is markedly different from that of the trivalent species. 

Another characteristic of the solvent extraction system is the high solute concentration in both aqueous and organic phases, which influences greatly the size of the required installation. Concentrations of rare-earth oxides (REO) higher than 100 g/L are often reached in both phases. The process therefore requires only relatively small equipment. 

Peat Waxes. Peat waxes are much like montan waxes in that they contain three main components a wax fraction, a resin fraction, and an asphalt fraction. The amount of asphalt in the total yield is influenced strongly by the solvent used in the extraction. Montan waxes contain ca 50 wt % more of the wax fraction than peat waxes, and correspondingly lower percentages of the resin and asphalt fractions. The wax fraction in peat wax is chemically similar to that of the wax fraction in montan wax. 

The pH has a great influence on the en2ymatic processes during mashing. Through water treatment it is possible to bring about shifts in pH whereby the transformations are decisively induenced. ( -Amylase has a pH optimum at 5.4, a-amylase at 5.8, and the normal mash has a pH of about 5.4 during saccharification. The induence of the concentration of the mash is such that thin mash increases the yield of both extract and maltose (Table 9). 

Ryon, Daley, and Lowrie [Chem. Eng. Ftog., 55(10), 70, (1959), U.S. AFC ORNL-2951, I960]. Continuous extraction of uranium from sulfate-ore-leach liquors and kerosine -t- trihiityl phosphate and di(2-ethylhexyl)-phosphoric acid baffled vessels, turbine agitated. There is strong evidence of the influence of a slow chemical reaction. 

It cannot be overemphasized that knowledge of the characteristics of such eqidpment is surprisingly underdeveloped. The number of quantities that influence the rate of extraction is veiy large, and many of them are not well understood. Most of the available data were taken... 

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