The quantitative infrared and NIR spectrum of CH&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;I&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; vapor: vibrational assignments and potential for atmospheric monitoring

Johnson, Timothy J.; Masiello, Tony; Sharpe, Steven W.

doi:10.5194/acp-6-2581-2006

Cited by 47 publications

(31 citation statements)

References 65 publications

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“…These results are in excellent agreement with the literature values reported for the pure liquids, 34,36 and well within the Fourier transform-limited spectral resolution of ∼5 cm −1 produced by the 6 ps traces. Indeed, the difference between the literature value for the peak center and our measurement for diiodomethane is only 1 cm −1 .…”

Section: Resultssupporting

confidence: 82%

“…34 We confirm that the coherence corresponds to this mode by taking a numerical Fourier transform of the data starting at time zero and using an asymmetric Hann window for apodization. 29,35 The magnitude of the complex-valued Fourier transform (also known as the absolute value of the Fourier transform) is plotted in the right panel of Figure 4.…”

Section: Resultsmentioning

confidence: 79%

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Nonlinear terahertz coherent excitation of vibrational modes of liquids

Allodi

Finneran

Blake

2015

The Journal of Chemical Physics

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We report the first coherent excitation of intramolecular vibrational modes via the nonlinear interaction of a TeraHertz (THz) light field with molecular liquids. A TeraHertz-TeraHertz-Raman pulse sequence prepares the coherences with a broadband, high-energy, (sub)picosecond TeraHertz pulse, that are then measured in a TeraHertz Kerr effect spectrometer via phase-sensitive, heterodyne detection with an optical pulse. The spectrometer reported here has broader TeraHertz frequency coverage, and an increased sensitivity relative to previously reported TeraHertz Kerr effect experiments. Vibrational coherences are observed in liquid diiodomethane at 3.66 THz (122 cm −1 ), and in carbon tetrachloride at 6.50 THz (217 cm −1 ), in exact agreement with literature values of those intramolecular modes. This work opens the door to 2D spectroscopies, nonlinear in TeraHertz field, that can study the dynamics of condensed-phase molecular systems, as well as coherent control at TeraHertz frequencies.

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Section: Resultssupporting

confidence: 82%

Section: Resultsmentioning

confidence: 79%

Nonlinear terahertz coherent excitation of vibrational modes of liquids

Allodi

Finneran

Blake

2015

The Journal of Chemical Physics

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“…Mixing ratios were obtained by multi-component fits to selected sections of the mid-IR transmission spectra with a synthetic calibration nonlinear least-squares method (Griffith, 1996;Yokelson et al, 2007a) utilizing both the HITRAN (Rothman et al, 2009) spectral database and reference spectra recorded at Pacific Northwest National Laboratory (PNNL) (Sharpe et al, 2004;Johnson et al, 2006Johnson et al, , 2010. The species above accounted for nearly all the features observed in the smoke spectra.…”

Section: Open-path Fourier Transform Infrared Spectrometer Detailsmentioning

confidence: 99%

Laboratory measurements of trace gas emissions from biomass burning of fuel types from the southeastern and southwestern United States

et al. 2010

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Abstract. Vegetation commonly managed by prescribed burning was collected from five southeastern and southwestern US military bases and burned under controlled conditions at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The smoke emissions were measured with a large suite of state-of-the-art instrumentation including an open-path Fourier transform infrared (OP-FTIR) spectrometer for measurement of gas-phase species. The OP-FTIR detected and quantified 19 gas-phase species in these fires: CO 2 , CO, CH 4 , C 2 H 2 , C 2 H 4 , C 3 H 6 , HCHO, HCOOH, CH 3 OH, CH 3 COOH, furan, H 2 O, NO, NO 2 , HONO, NH 3 , HCN, HCl, and SO 2 . Emission factors for these species are presented for each vegetation type burned. Gas-phase nitrous acid (HONO), an important OH precursor, was detected in the smoke from all fires. The HONO emission factors ranged from 0.15 to 0.60 g kg −1 and were higher for the southeastern fuels. The fire-integrated molar emission ratios of HONO (relative to NO x ) ranged from approximately 0.03 to 0.20, with higher values also observed for the southeastern fuels. The majority of non-methane organic compoundCorrespondence to: R. J. Yokelson (bob.yokelson@umontana.edu) (NMOC) emissions detected by OP-FTIR were oxygenated volatile organic compounds (OVOCs) with the total identified OVOC emissions constituting 61 ± 12% of the total measured NMOC on a molar basis. These OVOC may undergo photolysis or further oxidation contributing to ozone formation. Elevated amounts of gas-phase HCl and SO 2 were also detected during flaming combustion, with the amounts varying greatly depending on location and vegetation type. The fuels with the highest HCl emission factors were all located in the coastal regions, although HCl was also observed from fuels farther inland. Emission factors for HCl were generally higher for the southwestern fuels, particularly those found in the chaparral biome in the coastal regions of California.

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“…The averaged grab sample spectra were analyzed either as single-beam spectra for those species with significant background concentrations (water (H 2 O), carbon dioxide (CO 2 ), carbon monoxide (CO), and methane (CH 4 )) or transmission spectra referenced to an appropriate background spectrum, for the following gases with negligible background signals: ethyne (C 2 H 2 ), ethene (C 2 H 4 ), propene (C 3 H 6 ), formaldehyde (HCHO), formic acid (HCOOH), methanol (CH 3 OH), acetic acid (CH 3 COOH), furan (C 4 H 4 O), glycolaldehyde (HOCH 2 CHO), phenol (C 6 H 5 OH), hydrogen cyanide (HCN), nitrous acid (HONO), ammonia (NH 3 ), peroxyacetyl nitrate (PAN, CH 3 COONO 2 ) and ozone (O 3 ). The mixing ratios were obtained by multi-component fits to selected regions of the spectra with a synthetic calibration nonlinear least-squares method Yokelson et al, 2007a) utilizing both the HITRAN (Rothman et al, 2009) and Pacific Northwest National Laboratory (PNNL) (Johnson et al, 2006;Johnson et al, 2010;Sharpe et al, 2004) spectral databases. NO and NO 2 were analyzed by peak integration of selected regions of their corresponding spectral features.…”

Section: Airborne Fourier Transform Infrared Spectrometer (Aftir)mentioning

confidence: 99%

Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

et al. 2011

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Abstract. We have measured emission factors for 19 trace gas species and particulate matter (PM 2.5 ) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as conifer forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps to close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous observations that urban deposition can impact the NO x emission factors and thus subsequent plume chemistry. For two fires, we measured both the emissions in the convective smoke plume from our airborne platform and the unlofted residual smoldering combustion emissions with our groundbased platform. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including high 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air Correspondence to: R. J. Yokelson (bob.yokelson@umontana.edu) quality impacts for smoke that disperses at ground level. We also show that the often ignored unlofted emissions can significantly impact estimates of total emissions. Preliminary evidence suggests large emissions of monoterpenes in the residual smoldering smoke. These data should lead to an improved capacity to model the impacts of biomass burning in similar temperate ecosystems.

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The quantitative infrared and NIR spectrum of CH<sub>2</sub>I<sub>2</sub> vapor: vibrational assignments and potential for atmospheric monitoring

Cited by 47 publications

References 65 publications

Nonlinear terahertz coherent excitation of vibrational modes of liquids

Nonlinear terahertz coherent excitation of vibrational modes of liquids

Laboratory measurements of trace gas emissions from biomass burning of fuel types from the southeastern and southwestern United States

Airborne and ground-based measurements of the trace gases and particles emitted by prescribed fires in the United States

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