On the nitrogen-induced far-infrared absorption spectra

1987 ◽  
Vol 65 (1) ◽  
pp. 90-93 ◽  
Author(s):  
P. Dore ◽  
A. Filabozzi
Keyword(s):  
Experimental Data ◽  
Absorption Spectrum ◽  
Shape Analysis ◽  
Infrared Absorption ◽  
Simple Procedure ◽  
Gaseous Mixture ◽  
Far Infrared ◽  
Line Shape Analysis ◽  
Infrared Absorption Spectra ◽  
Good Agreement

The rototranslational absorption spectrum of gaseous N2 is analyzed, considering quadrupolar and hexadecapolar induction mechanisms. The available experimental data are accounted for by using a line-shape analysis in which empirical profiles describe the single-line translational profiles. We thus derive the simple procedure that allows one to predict the N2 spectrum at any temperature. On the basis of the results obtained for the pure gas, we also propose a procedure to compute the far-infrared spectrum of the N2–Ar gaseous mixture. The good agreement between computed and experimental N2–Ar data indicates that it is possible to predict the far-infrared absorption induced by N2 on the isotropic polarizability of any interacting partner.

Far infrared absorption of the gaseous CH4–Ar mixture

1990 ◽  
Vol 68 (10) ◽  
pp. 1196-1199 ◽  
Author(s):  
P. Dore ◽  
A. Filabozzi
Keyword(s):  
Experimental Data ◽  
Absorption Spectrum ◽  
Low Frequency ◽  
Far Infrared ◽  
Infrared Region ◽  
Low Frequencies ◽  
High Frequencies ◽  
Line Shape Analysis ◽  
Spectral Contribution ◽  
Pure Methane

We present the first measurements of the rototranslational absorption spectrum of the CH4–Ar gaseous system in the far infrared region 40–600 cm−1. Measurements were made at 296, 243, and 195 K at densities as low as possible; the binary absorption spectrum of the CH4–Ar pair was then obtained. We performed a line-shape analysis of these spectra following the procedure previously introduced for pure methane. We find that the experimental data can be described at high frequencies by using ab initio values of the octopole and hexadecapole multipole moments and anisotropic overlap intensities very close to those used for pure methane. At low frequencies, the computed spectrum is significantly lower than the experimental data at any temperature. We thus include in our analysis a low-frequency spectral contribution associated with the isotropic overlap induction mechanism. Good fits of the experimental data are then obtain at each temperature over all the spectral range.

scholarly journals Atmospheric Lifetimes, Infrared Absorption Spectra, Radiative Forcings and Global Warming Potentials of NF<sub>3</sub> and CFC-115

2016 ◽  
Author(s):  
Anna Totterdill ◽  
Tamás Kovács ◽  
Wuhu Feng ◽  
Sandip Dhomse ◽  
Christopher J. Smith ◽  
...  
Keyword(s):  
Global Warming ◽  
Cross Sections ◽  
Infrared Absorption ◽  
Radiative Forcing ◽  
Climate Model ◽  
Radiative Forcings ◽  
Atmospheric Window ◽  
Infrared Absorption Spectra ◽  
Global Warming Potentials ◽  
Good Agreement

Abstract. Fluorinated compounds such as NF3 and C2F5Cl (CFC-115) are characterised by very large global warming potentials (GWPs) which result from extremely long atmospheric lifetimes and strong infrared absorptions in the atmospheric window. In this study we have experimentally determined the infrared absorption cross-sections of NF3 and CFC-115, calculated the radiative forcing and efficiency using two radiative transfer models and identified the effect of clouds and stratospheric adjustment. The infrared cross sections are in good agreement with previous measurements, whereas the resulting radiative forcings and efficiencies are, on average, around 10 % larger. A whole atmosphere chemistry-climate model was used to determine the atmospheric lifetimes of NF3 and CFC-115 to be (616 ± 34) years and (492 ± 22) years, respectively. The GWPs for NF3 are estimated to be 14 600, 19 400 and 21 400 over 20, 100 and 500 years, respectively. Similarly, the GWPs for CFC-115 are 6120, 8060 and 8630 over 20, 100 and 500 years, respectively.

Interpretation of far-infrared absorption spectra in germanium

1977 ◽  
Vol 21 (10) ◽  
pp. 979-982 ◽  
Author(s):  
N.O. Lipari ◽  
M. Altarelli ◽  
E. Tosatti
Keyword(s):  
Absorption Spectra ◽  
Infrared Absorption ◽  
Far Infrared ◽  
Infrared Absorption Spectra
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