Emergency petroleum conservation: a review and analysis of selected measures

ORNL was asked by the Economic Regulatory Administration to (1) collect, screen, and recommend a limited number of emergency measures that might conserve petroleum in residential and commercial buildings and in commercial transportation and (2) provide a detailed analysis of the energy savings and the economic and environmental impacts associated with restricting the hours of operation of commercial buildings. A total of 41 emergency measures were identified that might conserve petroleum, and these were reduced to a list of five that seemed most promising. Analysis of the measure to restrict hours of operation for commercial buildings shows that it might save 4 to 6% of annual commercial building energy use. The type of fuel conserved would vary widely from region to region, and appreciable negative economic impacts would result from implementing the measure

Size and Temperature Dependence of Band-Edge Excitons in PbSe Nanowires

We report the attenuance and temperature-dependent photoluminescence spectra of PbSe nanowires with diameters between 5.6 and 26.4 nm (12−23% relative standard deviation) and lengths greater than 1 μm. The nanowire first exciton energy varies between 0.3 and 0.6 eV as the diameter decreases from 26.4 to 5.6 nm, respectively. Compared to spherical PbSe nanocrystals, PbSe nanowires show less quantum confinement and larger Stokes shifts. The band gap temperature coefficient (d<i>E</i>_g/d<i>T</i>) decreases as the nanowire diameter decreases, consistent with previous results for PbSe spherical nanocrystals