Selectivity significance

For the PS case, a three-variable Box-Behnken response surface methodology (RSM) design using formulation variables has been carried out. For the RF system, an eight-variable fractional-factorial screening study was done first to select significant factors, and this was followed by two RSM s which were similar in design to the one done for PS. The results have led directly to substantial improvements in both materials. 

Selective oxidation of p-xylene to terephthaldehyde (TPAL) on W-Sb oxide catalysts was studied. While WO3 was active in p-xylene conversion but non-selective for TPAL formation, addition of Sb decreased the activity in p-xylene conversion but increased TPAL selectivity significantly. Structure change was also induced by Sb addition. Evidences from various characterization techniques and theoretical calculation suggest that Sb may exist as various forms, which have different p-xylene adsorption property, reactivity toward p-xylene and TPAL selectivity. Relative population of each species depends on Sb content. 

NOTE If Z(N) is greater than the absolute value of the z-statistic (Normal Curve one-tailed) we reject the null hypothesis and state that there is no significant difference in rl and r2 at the selected significance level. 

Selectivity. Selectivity in a physical adsorption system may depend on differences in either equilibrium or kinetics, but the great majority of adsorption separation processes depend on equilibrium-based selectivity. Significant kinetic selectivity is. in general, restricted to molecular sieve adsorbents—carbon molecular sieves, zeolites, or zeolite analogues. 

The zerz-butyldimethyl silyl group also behaves as stereodirecting group since it enhances the diastereofacial selectivity significantly in the endoperoxidation of dienes 25. (Sch. 11) [26],... 

Entries 1, 2, 8, or 9). On the other hand, the silyl ethers 90-94 provided the desired endo-adduct A predominantly (Entries 3-7). In the case of the bulkier silyl ethers 93 and 94, the n-facial selectivity significantly decreased (Entries 6 and 7 compared to 3-5). As anticipated, by employing the silyl ethers 90-92 for the IMDA reaction, the desired cycloadduct A for the syntheses of mniopetal F and kuehneromycin A was obtained stereoselectively. 

Finally, for a selected significance level, the computed Fischer variable value F = (S 3/Vna)/(S /v2) determines whether the model is adequate or not by comparison with... 

This chapter deals with selected significant substances both natural and synthetic with a special stress on their behaviour during heating and at high temperatures. The compounds and systems selected are those most frequently encountered in technological practice and simultaneously characteristic for their features of ceramic and glass-making raw materials. The less frequently utilized and more specialized raw materials will be dealt with in later chapters in connection with the individual types of materials. 

The absorption with the physical solvents and hybrid solvents improve the absorption selectivity significantly for H2S and other sulfur compounds, including COS, mercaptans, and CS2. 

As an attempt to Improve the selectivity of oxygen permeation, copolymers with FA, and polymers of fluoroalkyl substituted S2 were synthesized. The results are also shown In Figure 5. Introduction of fluoroalkyl groups, at present, does not Improve the selectivity significant. 

As in many hydrocarbon processes, the normal process of deactivation is by carbon laydown, and is inevitable in catalyst systems which are not perfectly selective significant quantities of carbon, say 10-20 wt% on the... 

Probably the first example reporting enzymatic polymerization of vinyl monomers was reported in 1951 by Parravano [1] on the oxidase-initiated polymerization of methyl methacrylate. However, it was only in the 1990s that this reaction type was further investigated. Ever since then, enzymatic polymerizations of vinyl monomers have been experiencing a steadily growing popularity [2-5]. Inspired by the very mild reaction conditions combined with the usually high selectivity, significant benefits of biocatalysis have also been assumed for polymer synthesis. 

Other. -protecting groups such as benzyloxycarbonyl and benzoyl derivatives give similar results. In the alanine and valine series, the selectivity significantly decreases. 

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