Enrichment ratio

Thus R and k can be obtained from data pertaining only to the assays of the materials involved in the process. This relationship is very useful when the weights of the feed and of the concentrate are not available. It may be mentioned here that the quantity R, by itself, gives no information about the quantities of the concentrate and the tailings. However, R and k, when considered jointly, can adequately express metallurgical results. The enrichment ratio is c/f which is the ratio of the grade of the concentrate to the grade of the feed. 

Enrichment ratio (pesticide contributed by sediment) Application day (Julian Calendar)... 

Satake and coworkers131 studied lead accumulation and location in the shoots of the aquatic liverwort, Scapania undulata, in stream water (Pb content, 20 p-gl-1) at a mine in England. The lead concentration in the shoots ranged from 7 to 24 mgPbg-1 on a dry weight basis, giving an enrichment ratio of 3.5 x 105 — 1.2 x 106. Lead was localized in the cell wall131. 

Similarly, using Eq. (7.6) the enrichment ratio gb for the less incompatible element is defined by ... 

An integrated microfabricated cell sorter has been constructed using a control layer and a fluidic layer fabricated on PDMS [890]. The control layer consists of valves that will be pneumatically controlled by pressurized N2. This device is superior to an electrokinetic sorter, which suffers from buffer incompatibilities and frequent voltage adjustments because of ion depletion or pressure imbalance due to evaporation. E. coli cells expressing EGFP were sorted and selected out from a cell mixture which also contained E. coli cells expressing the / -nitrobenzyl (PNB) esterase. About 480,000 cells have been sorted at a rate of 44 cefls/s in 3 h. The recovery yield was 40% and the enrichment ratio was about 83-fold [890]. 

The high enrichment ratio observed for titanium in the deposit is difficult to explain if all the metal in the coal is present in the mineral state. The data can be interpreted as an indirect indication of the presence in the feed slurry of an unstable titanium species which, upon contact with the catalyst surface, codeposits with carbon, boron, and other metals. A plausible explanation for this observation would be that organotitanium compounds exist in the coal and that they thermally or catalytic ally decompose to yield a stable inorganic species. Some recent model compound studies by Treblow and coworkers have indicated that... 

Table 7 Periodic system depicting the relative enrichment (ratio > 1) of the elements in sea water as compared to river water elements enriched in sea water (mobile elements) are shaded (after Faure 1991, Merkel and Sperling 1996, 1998)...

With all separations there must be a tradeoff between yield and purity - high loss probabilities inevitably accompany high enrichment ratios. The underlying cause for this phenomenon is illustrated in Fig. 6.3. Although the mean mutant signal intensity can be maximally differentiated from wild type as discussed above, the expression, labeling and measurement processes introduce a point spread function that can cause... 

Fig. 6.5. Peak spreading strongly affects enrichment ratio at fixed probability of retention. The coefficient of variance CV is equal to the ratio of the standard deviation to the mean, and is a measure of peak breadth. For example, in both curves shown in Fig. 6.3 the CV is 1.0. The enrichment ratio was calculated for a situation in which mutant fluorescence intensity was double wild-type fluorescence intensity, the mutant was initially present at 1 in 106 cells, and the probability of retention was fixed at 95 %. The logarithmic fluorescence intensity was assumed to follow a Gaussian distribution. Fixing the probability of retention defines the cutoff fluorescence value for screening at a given CV. Enrichment ratio drops precipitously with increasing CV, as the mutant and wild-type fluorescence distributions begin to overlap. At a CV of 0.2, the enrichment factor is 600. However, at a CV of 0.4, the enrichment factor has dropped to 3 Clearly, every effort should be expended to minimize peak spreading and subsequent overlap of the mutant and wild-type fluorescence distributions.

Fig. 9-5. Magnetic field dependence of the relative isotope enrichment ratios observed in reaction 9-19 for ( Ge) and o for J( Ge). (Reproduced from Ref. [14] by permission from The American Chemical Society)...

The relationship between the separation hictor and the enrichment ratio was calculated (Figure-6). As the CO separation factor of Na-LSX at 2I3K is 1.1, it is predicted that the enrichment ratio for a single stage of this VPSA will be 2.5. 

Enrichment Ratio (ER). This parameter is determined by dividing the elemental concentration in each output by that in the raw shale. This ratio expresses the relative enrichment in each output stream independent of the mass of the input and output stream. 

Table V. Enrichment Ratios ( R) and Relative Imbalances (Rl) for Trace Elements in the Fischer Assay of Oil Shale...

Since eroded material frequently differs in composition from the original soil, the loss of plant nutrients in runoff may be expressed in terms of an enrichment ratio (E.R.). This is the ratio of the concentration of that element in the runoff to that in the original soil (Barrows and Kilmer, 1963) ... 

Thus, displacement chromatography provides an attractive procedure of trace enrichment. An enrichment ratio of several orders of magnitude can easily be achieved in practice. Such high ratios are possible because of the squeezing effect of displacement on trace bands (if the band is ten times narrower as in Fig-... 

To prevent grain boundary segregation, methods based on the conelation of enrichment ratio with the inverse of solid solubility have been used in several cases. Johnson et al., for example, ) proposed doping nickel-based alloys with additives such as hafnium, zirconium or lanthanum in order to remove sulfur from solution by the formation of sulfides during solidification thus preventing segregation and subsequent embrittlement. 

Figure 34-10. Effect of sintered-glass porosity on enrichment ratio. SDS, sodium docecyl sulfate CPC, cetylpyridinium chloride DADS, sodium n-hexyl diphenyloxide disulfonate.

Figure 34-10 shows that pore size affects the enrichment ratio for the removal of surfactants from a water system. Figure 34-11, p. 401, shows an apparatus for small scale laboratory separations. 

SP, styrene in instantaneous copolymer. c SpiSm, styrene enrichment ratio. 

It is practically impossible to obtain reliable comparative values for the HETP s of packed columns and for the plate efficiencies (or average enrichment ratios) of ])late colunms from data published in the literature, since these data refer to various test mixtures and were obtained under different conditions. Only in rare cases are all the necessary data, mentioned in section 4.10, given. Some agreement on a standardized... 

---