Extract defined

Soil treatment, 25 834-843, 843-845 bioremediation, 25 835-836 electrokinetics, 25 843-844 ex situ bioremediation, 25 836, 842-843 in situ air stripping, 25 844 in situ bioremediation, 25 836-842 plume containment, 25 835 soil flushing, 25 844 soil vapor extraction, 25 844 sulfur use in, 23 591 vitrification, 25 844-845 Soil-vapor extraction defined, 3 759t... 

Janssen-Jurkovicova et al. (1994) presented a conceptual model for CCB weathering, which breaks the process into four phases. Figure 2 illustrates their model for weathering of alkaline fly ash (i.e., fly ash producing alkaline water extracts defined as fly ash having Ca/S > 2.5 by Ainsworth Rai 1987), modified using observations of Warren Dudas (1984). In phase 1, oxides and soluble salts present on ash particle surfaces dissolve in contact with water. Hydrolysis of metal oxides (especially CaO) results in a rapid rise of pH to values of approxi-... 

Since we know the compositions of Vw and L +i and their mass ratio, M can be located by the lever rule described in Section 3.10. The point on Fig. 11.4 corresponding to solvent/feed = 0.56 is M, and the point of intersection of a line through M] and Lw with the saturated extract defines V at y = 0.33 because M, Vn, and Lw must lie on the same straight line. The compositions of all streams are now established. 

These Guidelines deal with thermal process flavorings they do not apply to foods, flavoring extracts, defined flavoring substances or mixtures of flavoring substances and flavor enhancers. 

The geometrical measurements previously extracted help the making decision system to decide for example whether the defect is linear or not. This defect discrimination into two categories is considered as a first attempt for defect classification. To this end, we define a linearity ratio (Ri) Rl =Length / width. If Rl is equal or near to "1", the defect is volumic, otherwise it is a linear defect. 

A variety of methods have been developed by mathematicians and computer scientists to address this task, which has become known as data mining (see Chapter 9, Section 9.8). Fayyad defined and described the term data mining as the nontrivial extraction of impHcit, previously unknown and potentially useful information from data, or the search for relationships and global patterns that exist in databases [16]. In order to extract information from huge quantities of data and to gain knowledge from this information, the analysis and exploration have to be performed by automatic or semi-automatic methods. Methods applicable for data analysis are presented in Chapter 9. 

In evaluating the efficiency of an extraction, however, we must consider the solute s total concentration in each phase. We define the distribution ratio, D, to be the ratio of the solute s total concentration in each phase. 

Interfacial Mass-Transfer Coefficients. Whereas equiHbrium relationships are important in determining the ultimate degree of extraction attainable, in practice the rate of extraction is of equal importance. EquiHbrium is approached asymptotically with increasing contact time in a batch extraction. In continuous extractors the approach to equiHbrium is determined primarily by the residence time, defined as the volume of the phase contact region divided by the volume flow rate of the phases. 

Dual solvent fractional extraction (Fig. 7b) makes use of the selectivity of two solvents (A and B) with respect to consolute components C and D, as defined in equation 7. The two solvents enter the extractor at opposite ends of the cascade and the two consolute components enter at some point within the cascade. Solvent recovery is usually an important feature of dual solvent fractional extraction and provision may also be made for reflux of part of the product streams containing C or D. Simplified graphical and analytical procedures for calculation of stages for dual solvent extraction are available (5) for the cases where is constant and the two solvents A and B are not significantly miscible. In general, the accurate calculation of stages is time-consuming (28) but a computer technique has been developed (56). 

Diffusion and Mass Transfer During Leaching. Rates of extraction from individual particles are difficult to assess because it is impossible to define the shapes of the pores or channels through which mass transfer (qv) has to take place. However, the nature of the diffusional process in a porous soHd could be illustrated by considering the diffusion of solute through a pore. This is described mathematically by the diffusion equation, the solutions of which indicate that the concentration in the pore would be expected to decrease according to an exponential decay function. 

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