Search results for "Methane infrared spectra"
showing 3 items of 3 documents
Model, software and database for line-mixing effects in the ν3 and ν4 bands of CH4 and tests using laboratory and planetary measurements-I: N2(and ai…
2006
International audience; Absorption spectra of the infrared ν3 and ν4 bands of CH4 perturbed by N2 over large ranges of pressure and temperature have been measured in the laboratory. A theoretical approach accounting for line mixing is proposed to (successfully) model these experiments. It is similar to that of Pieroni et al. [J Chem Phys 1999;110:7717–32] and is based on state-to-state rotational cross-sections calculated with a semi-classical approach and a few empirical parameters. The latter, which enable switching from the state space to the line space, are deduced from a fit of a single room temperature spectrum of the ν3 band at 50 atm. The comparisons between numerous measured and ca…
Model, software, and database for line-mixing effects in the ν3 and ν4 bands of CH4 and tests using laboratory and planetary measurements. I. N2 (and…
2006
Absorption spectra of the infrared ν3 and ν4 bands of CH4 perturbed by N2 over large ranges of pressure and temperature have been measured in the laboratory. A theoretical approach accounting for line mixing is proposed to (successfully) model these experiments. It is similar to that of Pieroni et al. [J Chem Phys 1999;110:7717–32] and is based on state-to-state rotational cross-sections calculated with a semi-classical approach and a few empirical parameters. The latter, which enable switching from the state space to the line space, are deduced from a fit of a single room temperature spectrum of the ν3 band at 50 atm. The comparisons between numerous measured and calculated spectra under a…
Model, software and database for line-mixing effects in the nu3 and nu4 bands of CH4 and tests using laboratory and planetary measurements - II : H2 …
2006
International audience; The absorption shapes of the nu(2), nu(3) and nu(4) infrared bands of CH4 perturbed by H-2 in large ranges of pressure and temperature have been measured in the laboratory. In order to model these spectra, the theoretical approach accounting for line-mixing effects proposed for CH4-N-2 and CH4-air and successfully tested in the companion paper (1), is used. As before, state-to-state rotational rates are used together with some empirical parameters that are deduced from a fit of a single room temperature spectrum of the nu(3) band at about 50 atm. The comparisons between measured and calculated spectra in the nu(3) and nu(4) regions under a vast variety of conditions …