Comparison with other treatment systems

The world-wide knowledge in design, construction and operation of hydraulic pipeline systems based on experimental investigation and operational experiences as well as on theoretical calculations has shown the efficiency and prospect of the pipeline transport of coal in comparison with other kinds of transport. However, at a level of technical projects a series of weaknesses and/or imperfections in contemporary used systems of the coal pipelining with water used as a carrier liquid have been detected. One of them is a rather difficult, energy consuming and expensive process of dehydration of coal slurry before combustion. Besides, transport of a great quantity of ballast - the carrier water - also requires considerable power inputs and usually also expensive water treatment before reutilization or... 

We review the Douglas-Kroll-Hess (DKH) approach to relativistic density functional calculations for molecular systems, also in comparison with other two-component approaches and four-component relativistic quantum chemistry methods. The scalar relativistic variant of the DKH method of solving the Dirac-Kohn-Sham problem is an efficient procedure for treating compounds of heavy elements including such complex systems as transition metal clusters, adsorption complexes, and solvated actinide compounds. This method allows routine ad-electron density functional calculations on heavy-element compounds and provides a reliable alternative to the popular approximate strategy based on relativistic effective core potentials. We discuss recent method development aimed at an efficient treatment of spin-orbit interaction in the DKH approach as well as calculations of g tensors. Comparison with results of four-component methods for small molecules reveals that, for many application problems, a two-component treatment of spin-orbit interaction can be competitive with these more precise procedures. 

This section will focus primarily on a comparison of these ring systems with their heavier chalcogen analogues. The first selenium derivative benzo-l,2,5-selenadiazole was prepared more than 115 years ago by the condensation reaction of selenium dioxide with 1,2-diaminobenzene (Eq. 11.12) and other benzo derivatives may be prepared in a similar manner. The parent 1,2,5-selenadiazole has also been reported. This reagent has been employed to make the tellurium analogue via treatment with ethylmagnesium bromide followed by the addition of tellurium tetrachloride (Eq. 11.13). ... 

It is seen from Figure 6.7 that this system is much simpler, more cost-effective, and easier to operate in comparison with all other process systems discussed earlier. The treatment efficiency of the new flotation-filtration system is expected to be higher than that of the conventional reduction-precipitation system. The new flotation-filtration system also requires much less land space.15... 

The effectiveness of a combined reduction-biological treatment system for the decolorization of nonbiodegradable textile dyeing wastewater has been investigated. The bench-scale experimental comparison of this technique with other reported combined chemical-biological methods showed higher efficiency and lower cost for the new technique [35]. 

Comparisons of classical trajectory calculations with various versions of VTST have also been performed for quite a series of other reaction systems such as neutral radical association/dissociation and radical-surface association processes [27-30], In these studies, the various treatments employed... 

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