Refining effect

The refining effect of ion exchange treatment is of sufficient magnitude to permit the elimination of a substantial portion of activated carbon, or bone char requirement. At least a portion of the cost of operation of the ion exchange unit is thus paid for by the savings in requirement of color adsorbent. 

Five isotopomers of Sia were studied in Ref (20), and are labeled as follows Si- Si- Si (I) Si- Si- Si (II) Si- Si- Si (III) Si- "Si- Si (IV) Si- Si- °Si (V). Rotational constants for each (both corrected and uncorrected for vibration-rotation interaction) can be found towards the bottom of Table I. Structures obtained by various refinement procedures are collected in Table II. Two distinct fitting procedures were used. In the first, the structures were refined against all three rotational constants A, B and C while only A and C were used in the second procedure. Since truly planar nuclear configurations have only two independent moments of inertia (A = / - 4 - 7. = 0), use of B (or C) involves a redundancy if the other is included. In practice, however, vibration-rotation effects spoil the exact proportionality between rotational constants and reciprocal moments of inertia and values of A calculated from effective moments of inertia determined from the Aq, Bq and Co constants do not vanish. Hence refining effective (ro) structures against all three is not without merit. Ao is called the inertial defect and amounts to ca. 0.4 amu for all five isotopomers. After correcting by the calculated vibration-rotation interactions, the inertial defect is reduced by an order of magnitude in all cases. 

The principle of beneficence entails helping people to further their interests. As the primary moral principle quoted in medical codes and oaths, the principle of beneficence is fundamental to the practice of medicine and clinical research. For example, concerns about beneficence motivate physicians, pharmacologists, pharmacists, and clinical investigators, all of whom share the goal of conducting studies that will ultimately benefit society by producing or refining effective treatments. 

During electrolysis, the content of the following metals in the cathodic deposit decreases with respect to their level in the anode metal Si, Mn, Na, P, U from 24 to 7 ppb, Th from 51 to 11 ppb, and Sc from 43 to 9 ppb. The content of Cr remains almost constant compared to the anode. Ti increases slightly from 15 to 30 ppb. With a higher Ti content in the anode (115 ppb), a clear refinement effect is observed (24 ppb). 

Because of the concurrent refining effect, galvanoaluminum is deposited from organoaluminum electrolytes with a purity of >99.99%. This high purity contributes to many of the excellent properties of galvanoaluminum, as shown in Table 9. 

Excessively intensive reduction yields sulphidic compounds which remain dissolved in glass and impart to it a brown colour. The refining effect of sulphate is simultaneously suppressed. 

As a part of solar grade Si production, it is necessary to cast the material after refining. A substantial refining effect can be attained, if planar front is achieved during the solidification. The solubility of many impurities is higher in liquid Si than in solid Si. In directional solidification with a planar front, there will be a clearly defined interface observed between solid and liquid Si. 

At the solid/liquid interface, the concentration of the impurities in the solidified Si will be in equilibrium with the molten metal. The ratio between the two concentrations is defined as the partition coefficient, given by k = Cs/C, where Cs and C are the concentrations of solid and liquid. For k values less than 1, there will be a refining effect. The principle of refining by solidification is illustrated in Fig. 1.12. 

A single conformer of trifluoroacetic anhydride, CF3C(0)0C(0)CF3, is indicated by the analysis of gas electron diffraction data, but there is some doubt about the precise structure of this conformer.29 The two C=0 bonds have the synperiplanar orientation, but it is not possible to say whether the equilibrium structure is planar, with C2V symmetry, or distorted to C2 symmetry. The refined effective dihedral angle C-0-C=0 is 18(4)°, reasonably consistent with values of 16.5 and 13.9° given by MP2 and B3LYP calculations with the 6-31G basis set. 

Application of bioassays for toxicity testing in aquatic ecosystems is well under way. Recently, a risk framework for a preliminary and a refined effect assessment has been suggested (Straetmans et al., 2003). As part of the toxicity measurements, organic contaminants in aquatic samples are lOOx concentrated (using a XAD resin and acetone) and toxicity experiments are performed with dilution series (De Zwart and Sterkenburg, 2002). Major features of this framework are ... 

Refined effect assessment. The results from four acute or chronic bioassays of different taxonomic groups are expressed in a concentration factor where 50% effect is measured (EC50). These data then are used to construct a sensitivity distribution (De Zwart and Sterkenburg, 2002). The potentially affected fraction (PAF) is determined for the 100% sample (the as is sample). The negligible effect level is at a value for PAF = 5%. 

Refining Effects on Various Chemical Pulp Types... 

A large amount of molten metal in the feeding box provided a constant inflow into the column. The cadmium concentration of the zinc feed was 0.4% + 0.07 % for all experiments. The temperature of the zinc feed was set at 550°C. The temperature distribution was set at Ttop=850°C, Tmiddie=900°C and Tboiier=920°. Samples of the condensate fixed on the trays of the column enabled a measurement of the Murphree efficiency after an experiment. The refining effect also occurs in the boiling section. Because of the charge of cold zinc feed, the vapour condenses and the content of the less volatile element zinc is decreased in the vapour. 

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