The large-scale generation of electrical power by wind turbine fields is discussed. It is shown that the maximum power which can be extracted by a wind turbine is 16/27 or 59.3% of the power available in the wind. An estimate is made of the total electrical power which could be generated in the United States by utilizing wind energy. The material in this paper was presented by the authors in a one-semester course on energy science. It could also be used in an introductory physics class as an illustration of elementary fluid mechanics concepts and of the basic principles of energy and momentum conservation.
We have observed waveguiding in thin films of polymer gelatin on GaAs, LiNbO(3), glass, and aluminum substrates. A graded-index profile can be induced in the gelatin layer and tuned by wet processing. This makes it possible to form waveguides on any smooth surface. Locally sensitizing the gelatin waveguide with ammonium dichromate allows us to integrate single and multiplexed gratings on the same substrate to perform various functions for optical interconnects and signal processing. A waveguide grating coupler that converts free-space TEM(00) laser light to a two-dimensional spherical guided wave with 50 degrees angle of divergence has also been demonstrated. An optical clock distribution network on wafer-scale integrated circuits is feasible with this new technology.
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