The Choice of Approach

Alkylphenols can be synthesized by several approaches, including alkylation of a phenol, hydroxylation of an alkylbenzene, dehydrogenation of an alkylcyclohexanol, or ring closure of an appropriately substituted acycHc compound. The choice of approach depends on the target alkylphenol, availabihty of the starting materials, and cost of processing. The procedures discussed herein encompass commercial methods, general methods, and a few specific examples of commercial interest. 

Many process components do not conform to the ideal gas laws for pressure, volume and temperature relationships. Therefore, when ideal concepts are applied by calculation, erroneous results are obtained—some not serious when the deviation from ideal is not significant, but some can be quite serious. Therefore, when data are available to confirm the ideality or non-ideality of a system, then the choice of approach is much more straightforward and can proceed with a high degree of confidence. 

The fate of four petroleum mixtures has been evaluated using three approaches—evaluating the fate of (1) indicator chemicals, (2) the mixture of the whole with a surrogate, and (3) the hydrocarbon mixture as a whole. The four mixtures were crude oil, JP-5, mineral spirits, and diesel. The choice of approach requires the consideration of availability and quality of data on the mixture, the mobility and toxicity of the mixture, and the availability of site data (Custance et al. 1992). 

In summary, we have developed three methods of generating a band structure from atoms, molecular fragments, and nets. The first two should remind you of our approach to the MOs of molecules. The last is new but once the added complexity is reduced by the translational symmetry, the operations in developing the band structure are again similar to those for molecules. The choice of approach depends on the problem. Although the answer cannot depend on the approach chosen, the clarity and insight into a problem may well do so. 

Flexibility and judgement should be exercised in the choice of approach. 

Appropriate software is available for all the noise reduction procedures, and the choice of approach depends on the aim of the particular analysis. The time constant approach (e.g., lengthening of the time... 

Models to identify drug effects on gastrointestinal function should cover gastrointestinal motility, nausea and emesis liability, secretory function (e.g., acidic, ions, hormones), and absorption aspects. Both in vitro and in vivo assessments are available and can be used either in stand-alone SP studies or as specific endpoints integrated into toxicology studies. In addition, novel in sUico tools could also be considered. The choice of approach reflects the focus of a project and may involve isolated cells, organ tissues, and/or whole animals. 

The choice of approach to use in enzymatic production of cocoa butter substitutes or equivalents seems to be influenced by three main factors (Yamane, 1991) ... 

The NOAEL and the benchmark dose generally produce similar estimates of the reference dose. Each approach offers certain advantages, and the choice of approach depends on the strengths and weaknesses of the animal toxicity data set on which it is based. Human epidemiological data, when available, may complement but not replace the NOAEL or benchmark dose in estimating a chemical s reference dose. 

In summary, measurement of interfacial rheology can take one of two approaches, either dilational or shear. The choice of approach will depend on its suitability to particular applications. The most accurate and reproducible results tend to come from methods that utilize small, reversible applied stresses and strains, thus minimizing any disruption or damage to the interfadal layer. 

The choice of approach is very important with regards to any further processing of the nanomaterials for possible applications. During the past few years, bottom-up techniques based on the self-assembly of building blocks have attracted considerable attention for the synthesis of anisotropic nanoparticles. The use of some popular bottom-up techniques, for the rational design of spherical and highly... 

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