Plasmonically Enhanced Reflectance of Heat Radiation from Low-Bandgap Semiconductor Microinclusions

Increased reflectance from the inclusion of highly scattering particles at low volume fractions in an insulating dielectric offers a promising way to reduce radiative thermal losses at high temperatures. Here, we investigate plasmonic resonance driven enhanced scattering from microinclusions of low-bandgap semiconductors (InP, Si, Ge, PbS, InAs and Te) in an insulating composite to tailor its infrared reflectance for minimizing thermal losses from radiative transfer. To this end, we compute the spectral properties of the microcomposites using Monte Carlo modeling and compare them with results from Fresnel equations. The role of particle size-dependent Mie scattering and absorption efficiencies, and, scattering anisotropy are studied to identify the optimal microinclusion size and material parameters for maximizing the reflectance of the thermal radiation. For composites with Si and Ge microinclusions we obtain reflectance efficiencies of 57 - 65% for the incident blackbody radiation from sources at temperatures in the range 400 - 1600 {\deg}C. Furthermore, we observe a broadbanding of the reflectance spectra from the plasmonic resonances due to charge carriers generated from defect states within the semiconductor bandgap. Our results thus open up the possibility of developing efficient high-temperature thermal insulators through use of the low-bandgap semiconductor microinclusions in insulating dielectrics.Comment: Main article (8 Figures and 2 Tables) + Supporting Information (8 Figures

Reflectance computation for a specular only V-cavity

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Health-related and social factors predicting non-reemployment amongst newly unemployed

<p>Abstract</p> <p>Background</p> <p>Many researchers have examined the effect that mental health has on reemployment opportunities amongst the unemployed, but the results are inconclusive. Our aim in this study is to investigate the effects that different aspects of mental and physical health, as well as socio-demographic, social, and economic factors, have on reemployment.</p> <p>Methods</p> <p>A questionnaire was administered to 1,000 and answered by 502 newly registered unemployed Swedes, who were followed for one year using data from the Swedish National Labour Market Board. The differences between those reemployed and those not reemployed was analysed using stepwise logistic regression.</p> <p>Results</p> <p>General mental ill health amongst unemployed individuals measured by the General Health Questionnaire scale was associated with lower levels of reemployment after one year. This effect could not be explained by any of the scales measuring specific aspects of mental disease such as health-related level of function, rate of depression, burnout, or alcohol misuse. Instead being above 45, low control over one’s financial situation, being an immigrant, and visiting a physician during the last three months were better predictors of failure to be reemployed.</p> <p>Conclusion</p> <p>There are theoretical reasons to assume that psychological distress leads to a decreased reemployment rate amongst the unemployed. The results of this study partly endorse this hypothesis empirically, showing that general subjective mental distress decreases the rate of reemployment amongst newly unemployed individuals, although this effect was mediated by social and economic factors. Indicators of psychiatric disease had no significant effect on reemployment. The results of this study lead us to suggest the early introduction of financial counselling, psychological support, and other interventions for groups with lower reemployment rates.</p