Observation process advantages

The reaction of / -butoxycarbonyl hydrazones 263 with selenium oxychloride in CH2CI2 from — 20 °C to room temperature gave 2,3-dihydro-l,2,3-selenadiazoles 264 in 71-77% yields (Equation 33). Under these mild conditions, the aromatization process did not occur, and only 2,3-dihydro compounds were observed. The advantage of this reaction is the ease of workup. Pure compounds 264 were obtained simply by addition to the reaction mixture of an aqueous saturated solution of NaHCC>3 and subsequent evaporation of the organic solvent <2003JOC1947>. 

As shown in Table XII, a broad spectrum of fibers have been successfully dyed in the laboratory with a wide variety of dye classes. A significant process advantage as well as energy savings aspect is the observation that in most cases, the fabrics do not need a back-wash to remove unfixed dyestuffs. The unwashed dyed goods meet all commercial standards for crock and wash fastness. The only exceptions to the no back-wash requirement are in the cases of reactive, sulfur, azoic and pre-metalllzed dyes. 

The characteristic of these processes closely follows those of polycondensation reactions thus, a stepwise growth with all the limitations as described in Section 2.3.2 can be observed. An advantage - also from an environmental point of view - is that there are no low molecular weight products formed. 

The possibility to include judgments of quality is a great advantage with the principles of BES. This is possible since a BES is designed as a framework to combine multiple source of evidence for meta-analysis. Also, new kind of sensitivity analysis can be made. Spiegelhalter and Best (2003) consider the influence of expert judged qualities in three data sources through the observation process models. 

Large stepsizes result in a strong reduction of the number of force field evaluations per unit time (see left hand side of Fig. 4). This represents the major advantage of the adaptive schemes in comparison to structure conserving methods. On the right hand side of Fig. 4 we see the number of FFTs (i.e., matrix-vector multiplication) per unit time. As expected, we observe that the Chebyshev iteration requires about double as much FFTs than the Krylov techniques. This is due to the fact that only about half of the eigenstates of the Hamiltonian are essentially occupied during the process. This effect occurs even more drastically in cases with less states occupied. 

The advantages of this method are twofold (i) It is possible to observe minute changes in colour and structure before and during the process of melting. (2) It is possible to use a single crystal which, e.., is often obtained from a semi-micro sublimation. 

In a world increasingly conscious of the dangers of contact with chemicals, a process that is conducted within the walls of a vacuum chamber, such as the VDP process for parylene coatings, offers great advantages. Provided the vacuum pump exhaust is appropriately vented and suitable caution is observed in cleaning out the cold trap (trace products of the pyrolysis, which may possibly be dangerous, would collect here), the VDP parylene process has an inherently low potential for operator contact with hazardous chemicals. 

Concentration. The concentration of fmit juice requites removal of solvent (water) from the natural juice. This is commonly done by evaporation, but the derived juices may lose flavor components or undergo thermal degradation during evaporation. In freeze concentration, solvent is crystallized (frozen) in a relatively pure form to leave behind a solution with a solute concentration higher than the original mixture. Significant advantages in product taste have been observed in the appHcation of this process to concentration of certain fmit juices. 

The choice of boiler steam inlet conditions is usually dictated by the desire to achieve maximum output from the process steam flow. This requires high boiler steam pressure and temperature. However, there are practical considerations to observe. Above 40 bar more exacting feedwater treatment is necessary, and therefore it may be advantageous to maintain pressures below this figure. High steam and temperatures can also influence selection of boiler materials such as alloy steels. The upper limit for industrial applications is around 60 bara and 540°C. 

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