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Yutaka Matsumi

Bio: Yutaka Matsumi is an academic researcher from Nagoya University. The author has contributed to research in topics: Photodissociation & Laser-induced fluorescence. The author has an hindex of 37, co-authored 215 publications receiving 4730 citations. Previous affiliations of Yutaka Matsumi include Hokkaido University & University of Southern Denmark.


Papers
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Journal ArticleDOI
TL;DR: In this article, the quantum yield value of the O(3P) atoms produced directly in the photolysis of N2O at 193 nm at room temperature has been determined to be 0.005 ± 0.002.
Abstract: The O(3P) atom produced in the 193 nm photolysis of N2O has been detected by a technique of vacuum-ultraviolet laser-induced fluorescence spectroscopy around 130 nm. The quantum yield value of the O(3P) atoms produced directly in the photolysis of N2O at 193 nm at room temperature has been determined to be 0.005 ± 0.002. The O(3P) atom formation process in the reaction of O(1D) + N2O is also studied, and the channel branching ratio of O(3P) + N2O has been determined to be 0.04 ± 0.02 among the product channels, 2NO, N2 + O2, and O(3P) + N2O. Photodissociation processes of N2O at 193 nm and reaction processes of O(1D) + N2O system have been discussed on the basis of the experimental results. Because of importance of the O(1D) + N2O reaction in the stratosphere, impact of the experimental result of O(3P) formation from the O(1D) + N2O reaction on the stratospheric chemistry is also studied by one-dimensional atmospheric model calculations.

34 citations

Journal ArticleDOI
TL;DR: Results suggest that the single C-Cl bond rupture always occurs in the photolysis of these molecules except for CCl4, and the branching ratios between the spin-orbit states, Cl*(1/2)) and Cl(2P(3/2)), have also been determined for the photodissociation of the chlorinated compounds at 193.3 nm.
Abstract: Cl(2P3/2) and Cl*(2P1/2) atoms produced from the photodissociation of chlorofluorocarbons (CFCs) and chlorinated hydrocarbons at 193.3 nm have been detected quantitatively by a technique of vacuum ultraviolet laser-induced fluorescence (VUV-LIF) spectroscopy at 135.2 and 134.7 nm for j = 1/2 and 3/2, respectively. The quantum yields for total Cl-atom formation in the 193.3 nm photolysis at 295 ± 2 K have been determined to be 1.03 ± 0.09, 1.01 ± 0.08, 1.03 ± 0.08, 1.03 ± 0.10, 1.41 ± 0.14, 1.02 ± 0.08, and 0.98 ± 0.08 for CF2Cl2, CFCl3, CH2Cl2, CHCl3, CCl4, CHFCl2, and CCl3CF3, respectively. Those results suggest that the single C−Cl bond rupture always occurs in the photolysis of these molecules except for CCl4. Formation of two Cl atoms partly takes place in the photodissociation of CCl4. The quantum yields for total Cl-atom formation in the 193.3 nm photolysis of CHBr2Cl and CHBrClCF3 are 0.27 ± 0.02 and 0.28 ± 0.02, respectively, which suggests that the C−Br bond rupture is a main channel in the photo...

34 citations

Journal ArticleDOI
TL;DR: FTIR-smog chamber techniques were used to study the products of the Cl atom and OH radical and the possibility that the atmospheric oxidation of CxF2x+1CH=CH2 contributes to the observed burden of perfluorocarboxylic acids, Cxf2x-1COOH, in remote locations.
Abstract: FTIR-smog chamber techniques were used to study the products of the Cl atom and OH radical initiated oxidation of CF3CH=CH2 in 700 Torr of N2/O2, diluent at 296 K. The Cl atom initiated oxidation of CF3CH=CH2 in 700 Torr of air in the absence of NOx gives CF3C(O)CH2Cl and CF3CHO in yields of 70+/-5% and 6.2+/-0.5%, respectively. Reaction with Cl atoms proceeds via addition to the >C=C C=C< double bond leading to the formation of CxF2x+1C(O)HCH2OH and CxF2x+1CHOHCH2O radicals. Decomposition via C-C bond scission is the sole fate of CxF2x+1CH(O)CH2OH and CxF2x+1CH(OH)CH2O radicals. As part of this work a rate constant of k(Cl+CF3C(O)CH2Cl)=(5.63+/-0.66)x10(-14) cm3 molecule-1 s-1 was determined. The results are discussed with respect to previous literature data and the possibility that the atmospheric oxidation of CxF2x+1CH=CH2 contributes to the observed burden of perfluorocarboxylic acids, CxF2x+1COOH, in remote locations.

34 citations

Journal ArticleDOI
TL;DR: In this paper, the branching ratios for production of the resulting chlorine atoms in the 2P1/2 state relative to 2P3/2 states are determined to be 0.20±0.02 at 193 nm and 0.35±0.05 at 157 nm for HCl and 023±0 0.02
Abstract: Hydrogen chloride and methyl chloride are photodissociated at 193 and 157 nm. Branching ratios for production of the resulting chlorine atoms in the 2P1/2 state relative to the 2P3/2 state are determined to be 0.20±0.02 at 193 nm and 0.35±0.05 at 157 nm for HCl and 0.23±0.02 at 193 nm and 0.26±0.05 at 157 nm for CH3Cl. The Doppler profiles of the chlorine fragments have been measured and are interpreted by assuming their anisotropy parameters and translational energies. HCl undergoes a perpendicular optical transition at each of the two wavelengths. For CH3Cl, the transition is parallel at 193 nm and a mixture of parallel and perpendicular types at 157 nm.

33 citations

Journal ArticleDOI
TL;DR: In this paper, a cavity ring-down spectrometer (CRDS) was used to monitor the aerosol extinction coefficient at 532-nm using polystyrene particles with diameters between 150 and 500 nm.

33 citations


Cited by
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TL;DR: In this paper, the photodissociation processes occurring in molecular oxygen following the two-photon 3dπ(3Σ1g −) Rydberg excitation around 225 nm are presented to show the improvement in spatial resolution in the ion and electron images.
Abstract: The application of electrostatic lenses is demonstrated to give a substantial improvement of the two-dimensional (2D) ion/electron imaging technique. This combination of ion lens optics and 2D detection makes “velocity map imaging” possible, i.e., all particles with the same initial velocity vector are mapped onto the same point on the detector. Whereas the more common application of grid electrodes leads to transmission reduction, severe trajectory deflections and blurring due to the non-point source geometry, these problems are avoided with open lens electrodes. A three-plate assembly with aperture electrodes has been tested and its properties are compared with those of grid electrodes. The photodissociation processes occurring in molecular oxygen following the two-photon 3dπ(3Σ1g −)(v=2, N=2)←X(3Σg −) Rydberg excitation around 225 nm are presented here to show the improvement in spatial resolution in the ion and electron images. Simulated trajectory calculations show good agreement with experiment and ...

2,430 citations

Journal ArticleDOI
TL;DR: An overview of PFASs detected in the environment, wildlife, and humans, and recommend clear, specific, and descriptive terminology, names, and acronyms for PFAS, can be found in this article.
Abstract: The primary aim of this article is to provide an overview of perfluoroalkyl and polyfluoroalkyl substances (PFASs) detected in the environment, wildlife, and humans, and recommend clear, specific, and descriptive terminology, names, and acronyms for PFASs. The overarching objective is to unify and harmonize communication on PFASs by offering terminology for use by the global scientific, regulatory, and industrial communities. A particular emphasis is placed on long-chain perfluoroalkyl acids, substances related to the long-chain perfluoroalkyl acids, and substances intended as alternatives to the use of the long-chain perfluoroalkyl acids or their precursors. First, we define PFASs, classify them into various families, and recommend a pragmatic set of common names and acronyms for both the families and their individual members. Terminology related to fluorinated polymers is an important aspect of our classification. Second, we provide a brief description of the 2 main production processes, electrochemical fluorination and telomerization, used for introducing perfluoroalkyl moieties into organic compounds, and we specify the types of byproducts (isomers and homologues) likely to arise in these processes. Third, we show how the principal families of PFASs are interrelated as industrial, environmental, or metabolic precursors or transformation products of one another. We pay particular attention to those PFASs that have the potential to be converted, by abiotic or biotic environmental processes or by human metabolism, into long-chain perfluoroalkyl carboxylic or sulfonic acids, which are currently the focus of regulatory action. The Supplemental Data lists 42 families and subfamilies of PFASs and 268 selected individual compounds, providing recommended names and acronyms, and structural formulas, as well as Chemical Abstracts Service registry numbers. Integr Environ Assess Manag 2011;7:513–541. © 2011 SETAC

2,356 citations

Journal Article
TL;DR: Denman et al. as discussed by the authors presented the Couplings between changes in the climate system and biogeochemistry Coordinating Lead Authors: Kenneth L. Denman (Canada), Guy Brasseur (USA, Germany), Amnat Chidthaisong (Thailand), Philippe Ciais (France), Peter M. Cox (UK), Robert E. Austin (USA), D.B. Wofsy (USA) and Xiaoye Zhang (China).
Abstract: Couplings Between Changes in the Climate System and Biogeochemistry Coordinating Lead Authors: Kenneth L. Denman (Canada), Guy Brasseur (USA, Germany) Lead Authors: Amnat Chidthaisong (Thailand), Philippe Ciais (France), Peter M. Cox (UK), Robert E. Dickinson (USA), Didier Hauglustaine (France), Christoph Heinze (Norway, Germany), Elisabeth Holland (USA), Daniel Jacob (USA, France), Ulrike Lohmann (Switzerland), Srikanthan Ramachandran (India), Pedro Leite da Silva Dias (Brazil), Steven C. Wofsy (USA), Xiaoye Zhang (China) Contributing Authors: D. Archer (USA), V. Arora (Canada), J. Austin (USA), D. Baker (USA), J.A. Berry (USA), R. Betts (UK), G. Bonan (USA), P. Bousquet (France), J. Canadell (Australia), J. Christian (Canada), D.A. Clark (USA), M. Dameris (Germany), F. Dentener (EU), D. Easterling (USA), V. Eyring (Germany), J. Feichter (Germany), P. Friedlingstein (France, Belgium), I. Fung (USA), S. Fuzzi (Italy), S. Gong (Canada), N. Gruber (USA, Switzerland), A. Guenther (USA), K. Gurney (USA), A. Henderson-Sellers (Switzerland), J. House (UK), A. Jones (UK), C. Jones (UK), B. Karcher (Germany), M. Kawamiya (Japan), K. Lassey (New Zealand), C. Le Quere (UK, France, Canada), C. Leck (Sweden), J. Lee-Taylor (USA, UK), Y. Malhi (UK), K. Masarie (USA), G. McFiggans (UK), S. Menon (USA), J.B. Miller (USA), P. Peylin (France), A. Pitman (Australia), J. Quaas (Germany), M. Raupach (Australia), P. Rayner (France), G. Rehder (Germany), U. Riebesell (Germany), C. Rodenbeck (Germany), L. Rotstayn (Australia), N. Roulet (Canada), C. Sabine (USA), M.G. Schultz (Germany), M. Schulz (France, Germany), S.E. Schwartz (USA), W. Steffen (Australia), D. Stevenson (UK), Y. Tian (USA, China), K.E. Trenberth (USA), T. Van Noije (Netherlands), O. Wild (Japan, UK), T. Zhang (USA, China), L. Zhou (USA, China) Review Editors: Kansri Boonpragob (Thailand), Martin Heimann (Germany, Switzerland), Mario Molina (USA, Mexico) This chapter should be cited as: Denman, K.L., G. Brasseur, A. Chidthaisong, P. Ciais, P.M. Cox, R.E. Dickinson, D. Hauglustaine, C. Heinze, E. Holland, D. Jacob, U. Lohmann, S Ramachandran, P.L. da Silva Dias, S.C. Wofsy and X. Zhang, 2007: Couplings Between Changes in the Climate System and Biogeochemistry. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

2,208 citations