Sciences achievement-level performance

Figure 4. The NAEP science achievement-level performance at grades 4, 8 and 12 (5).

For the first time in the history of chemical sciences, theoretical predictions have achieved the level of reliability that allows them to rival experimental measurements in accuracy on a routine basis. Only a decade ago, such a statement would be valid only with severe qualifications as high-level quantum-chemical calculations were feasible only for molecules composed of a few atoms. Improvements in both hardware performance and the level of sophistication of electronic structure methods have contributed equally to this impressive progress that has taken place only recently. 

We did not review such calculations in any depth, the reason being two-fold first, before one performs such calculations, one should become acquainted with the basic phenomenological concepts and principles of a global or collective description of the interface. Secondly, while first principle calculations in surface science have achieved a high level of sophistication, their combination with crude models of the neighboring solvent is controversial. At any rate, choosing the proper combination is currently a fine art . 

A dramatic decrease of the time of analysis can be achieved by using narrower columns combined with an adjusted improved electronic pressure control system. As today in most forensic science laboratories the procedures developed with the normal capillary GC instrumentation are part of a quality management system, a major change using the possibilities of Fast GC requires a new validation. This, together with the high level of performance reached during the last 15 years in capillary GC, may to some extent slow down the process of innovation in this area. 

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