• Energy Research

Abstract The ability to operate factory buildings as free running will be very useful in the context of saving energy needed for providing adequate thermal comfort for workers in warm humid tropical climatic conditions. The upper limits of thermally comfortable temperatures were established with comfort surveys carried out in three factory buildings without much ventilation. The surveys were then repeated to determine the effects of ventilation as well. The comfort surveys indicated that workers acclimatized to warm humid climatic condition could tolerate up to 30 °C without much ventilation when engaged in light factory work. This comfort temperature limit can be increased up to 34 °C when indoor air velocities are maintained as high as 0.6 m s −1 . It is also shown that these studies validate the earlier predictions of adaptive models for warm humid climates. The ability of workers to tolerate elevated temperatures could be used to highlight some concepts that can be considered in the planning of large-scale industrial parks, so that factories could be operated with minimum energy allocated for providing thermal comfort.

It is believed that the successful implementation of the Antenna Solar Energy Conversion (ASEC) to the commercial level would revolutionize the solar energy utilization. Screening suitable materials and technologies by analyzing potential pros and cones all the way to commercial level would conserve much time and resources. Here carbon nanotube (CNT) known as the material of the 21st century is evaluated concerning many aspects to implement ASEC concept. Thermomechanical and electrical properties of CNT as regards to ASEC, interaction of CNT and CNT arrays with optical spectrum and existing and future CNT technologies that have the potential to overcome possible future obstacles are discussed. The economic aspects which govern the future of ASEC concept, with CNT as a basic material are also discussed.

Abstract Emission of thermal radiation from a surface can be controlled spectrally and spatially, and the polarization and coherence of the radiation field can be modified. Of the various methods available for altering the radiation properties from a surface, paint and coatings possess a clear advantage regarding the cost, ease of application and simplicity. In this paper, we comprehensively review the capabilities of paint and coating technologies for emission control and for possible new energy-related applications. We also present an overview of the involved theories, common design and fabrication methods and possible future research opportunities to optimize these paints and coatings for spectral selectivity for specific applications.

Abstract Exergy of electromagnetic radiation has been studied by a number of researchers for well over four decades in order to estimate the maximum conversion efficiencies of thermal radiation. As these researchers primarily dealt with solar and blackbody radiation, which have a low degree of coherence, they did not consider the partial coherence properties of thermal radiation. With the recent development of surface structures, which can emit radiation with high degree of coherence, the importance of considering the partial coherent properties in exergy calculation has become a necessity as the coherence properties directly influence the entropy of the wave field. Here in this paper we derive an expression for the exergy of quasi-monochromatic radiation using statistical thermodynamics and show that it is identical with the expressions derived using classical thermodynamics. We also present a method to calculate the entropy, thereby the exergy of partially coherent radiation using statistical thermodynamics and a method called matrix treatment of wave field.