Convective Heat Transfer of Al2O3 and CuO Nanofluids Using Various Mixtures of Water-Ethylene Glycol as Base Fluids

In this work, a numerical study has been performed on the convective heat transfer of Al2O3/Water-Ethylene Glycol (EG) and CuO/(W-EG) nanofluids flowing through a circular tube with circumferentially non-uniform heating (constant heat flux) under the laminar flow condition. We focus on the study of the effect of EG-water mixtures as base fluids with mass concentration ranging from 0% up to 100% ethylene glycol on forced convection. The effect on the flow and the convective heat transfer behavior of nanoparticle types, their volume fractions (φ=1-5%) and Reynolds number are also investigated. The results obtained show that the highest values of the average heat transfer coefficient is observed between 40% and 50% of EG concentration. The average Nusselt number increases with the increase in EG concentration in the base fluid, and the increase in the Reynolds number and volume fraction. For concentrations of EG above 60%, and for all volume fractions, the increase of thermal performance of nanofluids became inversely proportional to the increase of Reynolds number. In addition, CuO/(W-EG) nanofluids show the best thermal performance compared with Al2O3/ (W-EG) nanofluids

Comparison between microparticles and nanostructured particles of FeSn(2) as anode materials for Li-ion batteries

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Surface enhanced infrared absorption (SEIRA) spectroscopy using gold nanoparticles on As2S3 glass

International audienceThe development of infrared sensing platform requires adapted materials. In this work, we used sputtered gold nanoparticles on a chalcogenide glass to demonstrate that these infrared materials can be used as substrate for surface enhanced infrared absorption (SEIRA) spectroscopy. The sputtering parameters were optimized to get the highest possible enhancement. To assess it, a self-assembled monolayer of 4-nitrothiophenol was used. These preliminary results are promising and pave the way for various configurations of waveguide for integrated optical components

Surface Enhanced Infrared Absorption (SEIRA) Spectroscopy using Gold Nanoparticles on As2S3 Glass

AbstractSurface enhanced infrared absorption (SEIRA) spectroscopy was investigated using sputtered gold nanoparticles on the As2S3 chalcogenide glass. Islands films were sputtered on the substrate with various thicknesses from 11.1±0.9nm to 31.4±3.6nm. Infrared transmission spectra of 4-nitrothiophenol adsorbed on gold nanoparticles show that SEIRA effect was dependent of the thickness of discontinuous gold films. Only symmetric NO2 stretch (1336cm-1) was observed and enhanced due to surface selection rules. The best enhancement is one order of magnitude stronger than for a continuous gold film. The corresponding thickness measured by Atomic Force Microscopy is 16.3±0.5nm