Provenance best” method

Enzymatic epoxidation has proven to be the best method to achieve high enantio-selectivity348-350 [Eqs. (9.81) and (9.82)351 352]. 

Characterization of complex organic matter like humic substances (HS) is a formidable task (7). A variety of destructive and non-destructive methods have been applied. Among the non-destructive methods, spectroscopic methods, such as NMR and FT-IR have proven to be very useful in providing information about the structure of these materials as a whole. Of these, NMR has proven to be the best method for bulk characterization, especially solid-state I R, where the relative contribution of specific carbon types can be made (2). Different structural parameters (aromaticity,... 

The limit to the effectiveness of a gas cleaning device is its efficiency ip the removal of aerosols. Neither electrical nor thermal precipitation has proven practical for the rapid removal of aerosols, and filtration seems to be the best method of removal. Aerosol filters consist of loosely aggregated fibers, and in order to avoid excessive resistance to flow of gas, the mesh of the fiber must be larger than the size of the particle to be removed. There is therefore no screening action the removal of the particle depends entirely upon a chance collision of the particle with a fiber of the filter. Once having collided, the particle adheres by adsorptive forces. 

Application. Both the Tomich and the 2iV Newton-Raphson methods are proven methods and have been applied often. The Tomich method was part of the GMB system of The Badger Company, Cambric, Massachusetts, and is in many in-house simulators. Both methods are best for wide- or middle-boiling s iarations. Because one of the equations in the 2N Newton-R hson method is a dew- or bubble-point equation, it may work better for middle or more narrow-boiling mixtures than the Tomich method. Both methods have also been eq>plied to absorber-strippers, thou an SR method is still the best method for the most wide-boiling absorber-strippers. Because of the full Jacobian more numbers to manipulate), for columns over 50 stages these methods will use excessive computer time and memoiy. Also, the solution of the Jacobian is prone to failure when the number of stages is high, and so these methods are not recommended for tall columns. 

Kuksis (1995). This review is to be confined largely to the quadrupole instruments, which have proven best-suited for computer-controlled operation. The discussion is divided according to the methods used for sample introduction into direct probe/MS, GC/MS and LC/MS operation. 

As with other modulation techniques, the idea is to measure the reflectance while some external parameter is varied periodically. The modulation of the reflected beam can be separated from the unmodulated background, and the resulting spectrum represents some kind of derivative of the original spectrum, showing up its singularities in fine detail. The external parameter may be electric field, pressure or other stress, temperature, or even rotation of the sample. Of these, the first has proven most useful. Electroreflectance is therefore currently the best method for picking out the singularities... 

The goals and the final quantities to be obtained determine the method to be used. As a first approach, it is always worth checking if a documented and proven method exists. Standardized methods are often the best. They are developed by experts in the field and are usually of a high quality and are well documented. Frequently no standards can be applied and generally known methods have to be relied on. Sometimes situations occur when the whole of the measurement procedure has to be tailored for the specific situation. This is a very demanding task and considerable experience is required. 

Trost and coworkers137 have reported the polymer-supported palladium catalyzed cyclization of 1, l-bis(phenylsulfonyl)epoxyalkene 235 which gives cycloalkanes 236 and 237 in a 2 1 ratio (equation 143). This method has proven useful for the synthesis of macrocyclic compounds under neutral conditions without using high dilution technique. Temperature and concentrations are critical. The best results are achieved if a reaction mixture of 0.1-0.5 m is added to a preheated (at 65 °C) suspension of the catalyst. 

The benefits, risks, burdens, and effectiveness of a new method should be tested against those of the best current prophylactic, diagnostic and therapeutic methods. This does not exclude the use of placebo, or no treatment, where no proven prophylactic, diagnostic or therapeutic method exists. 

The primary purpose of medical research involving human subjects is to improve prophylactic, diagnostic and therapeutic procedures and the understanding of the aetiology and pathogenesis of disease. Even the best proven prophylactic, diagnostic, and therapeutic methods must continuously be... 

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