Effect of Morphology on Spectral Radiative Properties of Three-Dimensionally Ordered Macroporous Ceria Packed Bed

2013 ◽  
Vol 135 (12) ◽  
Author(s):  
Krithiga Ganesan ◽  
Jaona Randrianalisoa ◽  
Wojciech Lipiński
Keyword(s):  
Spectral Range ◽  
Near Infrared ◽  
Packed Bed ◽  
Radiative Properties ◽  
Before And After ◽  
Infrared Spectral ◽  
Thermochemical Processes ◽  
Path Lengths ◽  
Ordered Macroporous

In this paper, radiative characterization of a packed bed of novel three-dimensionally ordered macroporous (3DOM) ceria particles is performed in the spectral range relevant to solar thermochemical processes, 0.35–2.2 μm. Normal–hemispherical transmittance and reflectance of three samples of various thicknesses are measured. Monte Carlo ray-tracing (MCRT) and discrete ordinate methods are employed to identify transport scattering albedo and transport extinction coefficient in the spectral range corresponding to weak absorption in the semi-transparency band of ceria. 3DOM ceria particles are characterized by weaker scattering in comparison to sintered ceria ceramics, and increased transparency in the near-infrared spectral range 0.7–2 μm. The ordered pore-morphology of the 3DOM ceria after thermochemical redox cycling between temperatures 1373 K and 1073 K is altered due to sintering of walls of the 3DOM structure. The absorption coefficient of the packed bed is found to be practically independent of morphology. Radiative characterization of 3DOM ceria ceramics before and after thermochemical cycling suggests that preserving the 3DOM structure can lead to scattering characteristics that permit longer attenuation path lengths of incident concentrated solar radiation in the material, as well as be favorable for confinement of the near-infrared radiation during thermochemical cycling leading to favorable thermochemical conditions for fuel production.

Effect of Morphology on Spectral Radiative Properties of Three-Dimensionally Ordered Macroporous Ceria Packed Bed

2013 ◽  
Author(s):  
Krithiga Ganesan ◽  
Jaona Randrianalisoa ◽  
Wojciech Lipiński
Keyword(s):  
Spectral Range ◽  
Near Infrared ◽  
Packed Bed ◽  
Radiative Properties ◽  
Before And After ◽  
Infrared Spectral ◽  
Thermochemical Processes ◽  
Path Lengths ◽  
Ordered Macroporous

In this paper, radiative characterization of a packed bed of novel three-dimensionally ordered macroporous (3DOM) ceria particles is performed in the spectral range relevant to solar thermochemical processes, 0.35–2.2μm. Normal–hemispherical transmittance and reflectance of three samples of various thicknesses are measured. Monte Carlo ray-tracing and discrete ordinate methods are employed to identify transport scattering albedo and transport extinction coefficient in the spectral range corresponding to weak absorption in the semi-transparency band of ceria. 3DOM ceria particles are characterized by weaker scattering in comparison to sintered ceria ceramics, and increased transparency in the near-infrared spectral range 0.7–2 μm. The ordered pore-morphology of the 3DOM ceria after thermochemical redox cycling between temperatures 1373 K and 1073 K is altered due to sintering of walls of the 3DOM structure. The absorption coefficient of the packed bed is found to be practically independent of morphology. Radiative characterization of 3DOM ceria ceramics before and after thermochemical cycling suggests that preserving the 3DOM structure can lead to scattering characteristics that permit longer attenuation path lengths of incident concentrated solar radiation in the material, as well as be favorable for confinement of the near-infrared radiation during thermochemical cycling leading to favorable thermochemical conditions for fuel production.

Metastructures for the Giant Enhancement of Raman Scattering in the Near Infrared Spectral Range

JETP Letters ◽  
2020 ◽  
Vol 112 (1) ◽  
pp. 31-36
Author(s):  
V. I. Kukushkin ◽  
V. E. Kirpichev ◽  
E. N. Morozova ◽  
V. V. Solov’ev ◽  
Ya. V. Fedotova ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral

Quantum efficiency of silicon photodiodes in the near-infrared spectral range

2003 ◽  
Vol 42 (22) ◽  
pp. 4415 ◽  
Author(s):  
Chris Hicks ◽  
Mark Kalatsky ◽  
Richard A. Metzler ◽  
Alexander O. Goushcha
Keyword(s):  
Quantum Efficiency ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral

Optical properties of selected native and coagulated human brain tissues in vitro in the visible and near infrared spectral range

2002 ◽  
Vol 47 (12) ◽  
pp. 2059-2073 ◽  
Author(s):  
A N Yaroslavsky ◽  
P C Schulze ◽  
I V Yaroslavsky ◽  
R Schober ◽  
F Ulrich ◽  
...  
Keyword(s):  
Optical Properties ◽  
Human Brain ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral ◽  
Brain Tissues

scholarly journals Characterization of interferences to in situ observations of <i>δ</i><sup>13</sup>CH<sub>4</sub> and C<sub>2</sub>H<sub>6</sub> when using a cavity ring-down spectrometer at industrial sites

2017 ◽  
Vol 10 (6) ◽  
pp. 2077-2091 ◽  
Author(s):  
Sabina Assan ◽  
Alexia Baudic ◽  
Ali Guemri ◽  
Philippe Ciais ◽  
Valerie Gros ◽  
...  
Keyword(s):  
Near Infrared ◽  
Field Tests ◽  
Isotopic Signature ◽  
Ambient Conditions ◽  
Industrial Sites ◽  
Source Determination ◽  
Infrared Spectral ◽  
The Subject

Abstract. Due to increased demand for an understanding of CH4 emissions from industrial sites, the subject of cross sensitivities caused by absorption from multiple gases on δ13CH4 and C2H6 measured in the near-infrared spectral domain using CRDS has become increasingly important. Extensive laboratory tests are presented here, which characterize these cross sensitivities and propose corrections for the biases they induce. We found methane isotopic measurements to be subject to interference from elevated C2H6 concentrations resulting in heavier δ13CH4 by +23.5 ‰ per ppm C2H6 ∕ ppm CH4. Measured C2H6 is subject to absorption interference from a number of other trace gases, predominantly H2O (with an average linear sensitivity of 0.9 ppm C2H6 per  % H2O in ambient conditions). Yet, this sensitivity was found to be discontinuous with a strong hysteresis effect and we suggest removing H2O from gas samples prior to analysis. The C2H6 calibration factor was calculated using a GC and measured as 0.5 (confirmed up to 5 ppm C2H6). Field tests at a natural gas compressor station demonstrated that the presence of C2H6 in gas emissions at an average level of 0.3 ppm shifted the isotopic signature by 2.5 ‰, whilst after calibration we find that the average C2H6 : CH4 ratio shifts by +0.06. These results indicate that, when using such a CRDS instrument in conditions of elevated C2H6 for CH4 source determination, it is imperative to account for the biases discussed within this study.

Combustion Synthesis and Infrared Characterization of TiB2

2014 ◽  
Vol 602-603 ◽  
pp. 142-145
Author(s):  
Su Li ◽  
Jun Shou Li ◽  
Fang Zhao ◽  
Ming Yuan Wang ◽  
Xiao Juan Wu
Keyword(s):  
Hydrochloric Acid ◽  
Wave Band ◽  
Qualitative And Quantitative Analysis ◽  
Qualitative And Quantitative ◽  
High Temperature Synthesis ◽  
Hexagonal Shape ◽  
Before And After ◽  
Infrared Spectral ◽  
Middle Infrared

On the basis of magnesiothermy, with Mg powder, TiO2 powder and B2O3 powder as mixed reactants, relatively pure TiB2 powder was prepared by self-propagating high temperature synthesis (SHS) after leached in diluted hydrochloric acid with the suitable concentration. The product after leached was examined by XRD for qualitative and quantitative analysis, SEM for morphology analysis and infrared spectroscopy for transmittance analysis. It was found that diluted hydrochloric acid could decrease most of the impurities, and the proportion of TiB2 phase in the product is more than 99%, which was hexagonal shape crystal with the grain size of 200-300 nm. Compare with the infrared spectrogram of the middle infrared spectral region of the product of before and after acid pickling, it was found that the transmittance of TiB2 is extremely low in the range of 2000-4000 cm-1, which can be excellent infrared absorption material in the corresponding wave band.

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