Next page additive effects

When two or more groups which impart the same conformational bias are present, shift additivity will provide reasonable predictions. For example, the methyl groups in exo-3-exo-8-dimethyl-cis-decalin (next page) are either both equatorial or both axial, with the former arrangement obviously favored. Since this conformation preserves the spatial orientation of the methyl group in the monosubstituted model, then shift additivity will hold so long as the effect of the methyl group is assessed relative to the shifts of the conformationally fixed parent obtained at low temperature. 

Forecasts indicate that the United States will need an additional 355 billion watts of generating capacity in the next 20 years. Where will this energy come from A significant amount will be derived from coal-fired power plants. However, the major problems with these plants are air pollution and greenhouse gas (CO2) production (see "Chemistry in Focus Atmospheric Effects," on page 326). 

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