Experimental Determination of SO2, C2H2, and O2 UV Absorption Cross Sections at Elevated Temperatures and Pressures

1997 ◽  
Vol 51 (9) ◽  
pp. 1311-1315 ◽  
Author(s):  
J. Vattulainen ◽  
L. Wallenius ◽  
J. Stenberg ◽  
R. Hernberg ◽  
V. Linna
Keyword(s):  
Absorption Spectra ◽  
Wavelength Range ◽  
Cross Sections ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Reference Spectrum ◽  
Absorption Cross ◽  
Deuterium Lamp ◽  
Made In

A heated and pressurized quartz cell with 150.5-mm pathlength was used to experimentally determine UV absorption spectra and further absorption cross sections of SO2, C2H2, and O2 in the wavelength range between 200 and 400 nm. Spectra were recorded at room temperature, and at 600 and 800 °C and at absolute pressures between 1 and 6 bar. A 30-W deuterium lamp was used as a light source, and the light was detected with a photomultiplier tube through a 0.4-m Czerny–Turner monochromator. Slit widths of the monochromator were adjusted to achieve a 5 Å measurement bandwidth, and the scan through the wavelength range was made in 5 Å steps. For each individual temperature and pressure level, a reference spectrum was first recorded with the cell filled with nitrogen. After this, the cell was filled with the selected species mixed with nitrogen, and the absorption spectra were recorded in similar conditions. The studied gas mixtures were calibrated to 3% accuracy.

scholarly journals Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

2021 ◽  
pp. 000370282199044
Author(s):  
Wubin Weng ◽  
Shen Li ◽  
Marcus Aldén ◽  
Zhongshan Li
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Energy Utilization ◽  
Quantitative Detection ◽  
Absorption Cross ◽  
Hot Gas

Ammonia (NH3) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH3, accurate in situ detection of NH3 in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH3 in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH3 were determined and used for the calculation of the absorption cross-section of NH3 at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the [Formula: see text] transition of NH3 in the umbrella bending mode, v2, were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH3 decreases from ∼2 × 10−17 to ∼0.5 × 10−17 cm2/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH3 in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH3 combustion process. The concentrations of NH3 and nitric oxide (NO) in the post flame zone of NH3–methane (CH4)–air premixed flames at different equivalence ratios were measured.

Kinetics of the gas phase reaction OH + NO(+M)→HONO(+M) and the determination of the UV absorption cross sections of HONO

1997 ◽  
Vol 272 (5-6) ◽  
pp. 383-390 ◽  
Author(s):  
Palle Pagsberg ◽  
Erling Bjergbakke ◽  
Emil Ratajczak ◽  
Alfred Sillesen
Keyword(s):  
Gas Phase ◽  
Cross Sections ◽  
Uv Absorption ◽  
Phase Reaction ◽  
Absorption Cross ◽  
Gas Phase Reaction ◽  
Kinetics Of

scholarly journals UV absorption cross sections of vaporized 1-methylnaphthalene at elevated temperatures

2020 ◽  
Vol 126 (3) ◽  
Author(s):  
Ulrich Retzer ◽  
Hannah Ulrich ◽  
Florian J. Bauer ◽  
Stefan Will ◽  
Lars Zigan
Keyword(s):  
Cross Sections ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Absorption Cross

UV absorption cross sections of nitrous acid

2000 ◽  
Vol 34 (1) ◽  
pp. 13-19 ◽  
Author(s):  
A.S. Brust ◽  
K.H. Becker ◽  
J. Kleffmann ◽  
P. Wiesen
Keyword(s):  
Cross Sections ◽  
Nitrous Acid ◽  
Uv Absorption ◽  
Absorption Cross

scholarly journals A broadband optical cavity spectrometer for measuring weak near-ultraviolet absorption spectra of gases

2011 ◽  
Vol 4 (3) ◽  
pp. 425-436 ◽  
Author(s):  
J. Chen ◽  
D. S. Venables
Keyword(s):  
Absorption Spectra ◽  
Cross Sections ◽  
Optical Cavity ◽  
Absorption Cross ◽  
Enhanced Absorption ◽  
Cavity Enhanced Absorption Spectroscopy ◽  
Near Ultraviolet ◽  
Low Concentrations ◽  
Measured Absorption ◽  
Atmospheric Observations

Abstract. Accurate absorption spectra of gases in the near–ultraviolet (300 to 400 nm) are essential in atmospheric observations and laboratory studies. This paper describes a novel incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) instrument for measuring very weak absorption spectra from 335 to 375 nm. The instrument performance was validated against the 3B1-X1A1 transition of SO2. The measured absorption varied linearly with SO2 column density and the resulting spectrum agrees well with published spectra. Using the instrument, we report new absorption cross-sections of O3, acetone, 2-butanone, and 2-pentanone in this spectral region, where literature data diverge considerably. In the absorption minimum between the Huggins and Chappuis bands, our absorption spectra fall at the lower range of reported ozone absorption cross-sections. The spectra of the ketones agree with prior spectra at moderate absorptions, but differ significantly at the limits of other instruments' sensitivity. The collision-induced absorption of the O4 dimer at 360.5 nm was also measured and found to have a maximum cross-section of ca. 4.0×10−46 cm5 molecule−2. We demonstrate the application of the instrument to quantifying low concentrations of the short-lived radical, BrO, in the presence of stronger absorptions from Br2 and O3.

scholarly journals Scattering and Absorption Cross-sections of Atmospheric Gases in the Ultraviolet-Visible Wavelength Range (307–725 nm)

2020 ◽  
Author(s):  
Quanfu He ◽  
Zheng Fang ◽  
Ofir Shoshamin ◽  
Steven S. Brown ◽  
Yinon Rudich
Keyword(s):  
Refractive Index ◽  
Wavelength Range ◽  
Cross Sections ◽  
Rayleigh Scattering ◽  
Dispersion Relations ◽  
Optical Absorption Spectroscopy ◽  
Absorption Cross ◽  
Atmospheric Gases ◽  
Scattering Cross ◽  
Scattering Cross Sections

Abstract. Accurate Rayleigh scattering and absorption cross-sections of atmospheric gases are essential for understanding the propagation of electromagnetic radiation in planetary atmospheres. Accurate extinction cross-sections are also essential for calibrating high finesse optical cavities and differential optical absorption spectroscopy and for accurate remote sensing. In this study, we measured the scattering and absorption cross-sections of carbon dioxide, nitrous oxide, sulfur hexafluoride, oxygen, and methane in the continuous wavelength range of 307–725 nm using Broadband Cavity Enhanced Spectroscopy (BBCES). The experimentally derived Rayleigh scattering cross-sections for CO2, N2O, SF6, O2, and CH4 agree with refractive index-based calculations, with a difference of 1.5 % and 1.1 %, 1.5 %, 2.9 %, and 1.4 % on average, respectively. The O2-O2 collision-induced absorption and absorption by methane are obtained with high precision at the 0.8 nm resolution of our BBCES instrument in the 307–725 nm wavelength range. New dispersion relations for N2O, SF6, and CH4 were derived using data in the UV-vis wavelength range. This study provides improved refractive index dispersion relations, n-based Rayleigh scattering cross-sections, and absorption cross-sections for these gases.

scholarly journals Determination of the absorption cross-sections of higher order iodine oxides at 355 nm and 532 nm

2020 ◽  
Author(s):  
Thomas R. Lewis ◽  
Juan Carlos Gómez Martin ◽  
Mark A. Blitz ◽  
Carlos A. Cuevas ◽  
John M. C. Plane ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Atmospheric Chemistry ◽  
Absorption Cross Section ◽  
Absorption Cross ◽  
Time Resolved ◽  
Flight Mass Spectrometry ◽  
Iodine Oxides ◽  
Photo Ionization

Abstract. Iodine oxides (IxOy) play an important role in the atmospheric chemistry of iodine. They are initiators of new particle formation events in the coastal and polar boundary layer and act as iodine reservoirs in tropospheric ozone-depleting chemical cycles. Despite the importance of the aforementioned processes, the photochemistry of these molecules has not been studied in detail previously. Here, we report the first determination of the absorption cross sections of IxOy, x = 2, 3, 5, y = 1–12 at λ = 355 nm by combining pulsed laser photolysis of I2/O3 gas mixtures in air with time-resolved photo-ionization time-of-flight mass spectrometry, using NO2 actinometry for signal calibration. The oxides selected for absorption cross section determinations are those presenting the strongest signals in the mass spectra, where signals containing 4 iodine atoms are absent. The method is validated by measuring the absorption cross section of IO at 355 nm, σ355 nm, IO = (1.2 ± 0.1) ×  10–18 cm2, which is found to be in good agreement with the most recent literature. The results obtained are: σ355 nm, I2O3 

UV absorption spectrum and absorption cross sections of COF2at 296 K in the range 200 - 230 nm

1992 ◽  
Vol 19 (3) ◽  
pp. 281-284 ◽  
Author(s):  
Andreas Nölle ◽  
Horst Heydtmann ◽  
Richard Meller ◽  
Wolfgang Schneider ◽  
Geert K. Moortgat
Keyword(s):  
Absorption Spectrum ◽  
Cross Sections ◽  
Uv Absorption ◽  
Absorption Cross ◽  
Uv Absorption Spectrum
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