Energy dilemma

C. N. Cochran and co-workers, Use ofMluminum in Mutomobiles—Effect on the Energy Dilemma, SAE Paper 750421, Society of Automotive Engineers, Warrendale, Pa., Feb. 1975. 

A.D. Waltar, America the Powerless, Facing Our Nuclear Energy Dilemma, Cogito Books, Madison, Wisconsin, 1995. 

GAO Report to Congress, "Nuclear energy dilemma disposing of hazardous radioactive waste safely", 73, 1977. 

Since it is a stable molecule, one wants to supply additional energy to convert the linear structure to bent form, i.e., CO2 to C02-. Because of the high LUMO level of carbon dioxide, the transfer of one electron to free CO2 is thermodynamically unfavourable, requires a very negative redox potential up to the order of -1.9V vs Normal Hydrogen Electrode (NHE). In photocatalytic route, no semiconductor possesses the conduction band potential required for CO2 activation, there is a need to supply additional overvoltage which will lead to another energy dilemma. 

El-Halwagi, M. M. (1993). A process synthesis approach to the dilemma of simultaneous heat recovery, waste reduction and cost effectiveness. In Proceedings of the Third Cairo International Conference on Renewable Energy Sources ( A. I. El-Sharkawy and R. H. Kummler, eds.), Vol. 2, pp. 579-594. ... 

The entropy dilemma, i.e. small concentrations of valuable substances in used products leading to complicated and energy consuming recovery processes... 

If the primeval atmosphere did not contain enough CO2 to maintain a greenhouse climate, the much lower solar irradiation at that time would have led to frozen oceans. But that would make almost all the assumed synthetic mechanisms for the formation of biomolecules impossible Bada et al. (1994) consider external help as a way out of this dilemma. They assume that the energy from meteor impacts (diameters up to around 100 km), converted into heat, would have sufficed to melt the oceanic ice. If such a process were to have occurred periodically, chemical evolution reactions (see Chap. 4) could have taken place in the ice-free periods and have led finally to biogenesis. 

A major dilemma in any approach to energy conversion processes based on electron transfer reactions of molecular excited states is utilization of the stored redox products before back electron transfer can occur. 

Hence, a dilemma was encountered between energy density and stability for these various forms of carbonaceous materials that is, as the carbonaceous anode is more graphitic in structure, the degree of lithium ion intercalation may be closer to the ideal x = 1.0), and its potential profile may be closer to that of Li+/Li and remain relatively flat (therefore... 

In retrospect, the significance of Dahn s seminal work lies in two aspects (1) the fundamental understanding of how carbonaceous materials operate in nonaqueous electrolytes and (2) the more practical side of how the above dilemma concerning energy density and reversibility can be overcome. This knowledge dictates the development of electrolytes for state-of-the-art lithium ion chemistry. 

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