Energy efficiency limitations

Europe and the Challenge of Energy Security: Limitations and Strategies

The increasing dependence of European Union member countries on imported oil and gas has led to concerns about energy supply and security.  At the same time the share of clean energy in Europe’s energy consumption basket is increasing due to environmental issues. About a quarter of all energy consumption in the EU is natural gas, and most EU member states import almost all of their energy resou...

Resonant optical modulators beyond conventional energy- efficiency and modulation frequency limitations

Abstract: Modulator designs are proposed that can employ arbitrarily high-Q resonators to simultaneously achieve high energy efficiency and distortionless modulation at all (low/high) frequencies by completely decoupling optical cavity dynamics from the modulation frequency response. ©2010 Optical Society of America OCIS codes: (130.4110) Modulators; (130.3120) Integrated optics devices; (230.5...

Energy efficiency and performance limitations of linear adaptive control for transition delay

A reactive control technique with localised actuators and sensors is used to delay the transition to turbulence in a flat-plate boundary-layer flow. Through extensive direct numerical simulations, it is shown that an adaptive technique, which computes the control law on-line, is able to significantly reduce skin-friction drag in the presence of random three-dimensional perturbation fields with ...

Energy Efficiency –

Overcoming Efficiency Limitations of SnSBased Solar Cells

Dr. P. Sinermsuksakul, Dr. S. B. Kim, Prof. R. G. Gordon Department of Chemistry and Chemical Biology Harvard University Cambridge , MA , U.S.A E-mail: [email protected] L. Sun, H. H. Park, C. Yang School of Engineering and Applied Sciences Harvard University Cambridge , MA , U.S.A Prof. S. W. Lee Department of Physics and Division of Energy Systems Research Ajou University 443–749 ,...