Stabilization of the primary products of atomic oxygen (1D) reactions with carbon monoxide, carbon dioxide, methane and other hydrocarbons in cryogenic matrixes

1993 ◽  
Vol 97 (41) ◽  
pp. 10708-10711 ◽  
Author(s):  
J. Mark Parnis ◽  
Larry E. Hoover ◽  
Travis D. Fridgen ◽  
Rick D. Lafleur
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Atomic Oxygen ◽  
Primary Products

Low-Fluence Laser Induced Fragmentation and Desorption of 3,4,9,10-Perylenetetracarboxylic Dianhydride (PTCDA) Thin Film

2013 ◽  
Vol 543 ◽  
pp. 30-34 ◽  
Author(s):  
Aljona Ramonova ◽  
Tengiz Butkhuzi ◽  
Viktorija Abaeva ◽  
I.V. Tvauri ◽  
Soslan Khubezhov ◽  
...  
Keyword(s):  
Thin Film ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Kinetic Energy ◽  
Atomic Oxygen ◽  
Laser Light ◽  
Pulsed Laser ◽  
Molecular Fragmentation ◽  
Irradiation Pulse ◽  
Main Effect

Laser-induced fragmentation and desorption of fragments of PTCDA films vacuum-deposited on GaAs (100) substrate has been studied by time-of-flight (TOF) mass spectroscopy. The main effect caused by pulsed laser light irradiation (pulse duration: 10 ns, photon energy: 2.34 eV and laser fluence ranging from 0.5 to 7 mJ/cm2) is PTCDA molecular fragmentation and desorption of the fragments formed, whereas no desorption of intact PTCDA molecule was detected. Fragments formed are perylene core C20H8, its half C10H4, carbon dioxide, carbon monoxide and atomic oxygen. All desorbing fragments have essentially different kinetic energy. The mechanism of photoinduced molecular fragmentation and desorption is discussed.

The oxidation of Carbon with Atomic Oxygen

1959 ◽  
Vol 12 (2) ◽  
pp. 114 ◽  
Author(s):  
JD Blackwood ◽  
FK McTaggart
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Radio Frequency ◽  
Molecular Oxygen ◽  
Atomic Oxygen ◽  
Graphitic Carbon ◽  
Carbon Surface ◽  
Direct Oxidation ◽  
Radio Frequency Field ◽  
Frequency Field

Atomic oxygen, produced by dissociation of molecular oxygen in a radio frequency field, will react with amorphous or graphitic carbon at room temperatures and both carbon monoxide and carbon dioxide appear in the product gases. Carbon monoxide appears to be the primary product of oxidation of carbon, the carbon dioxide being produced by direct combination of carbon monoxide with oxygen which takes place mainly at the carbon surface. Atomic oxygen will also react with carbon dioxide to produce carbon monoxide and molecular oxygen but the quantity of carbon monoxide produced by this reaction is small compared to that produced by direct oxidation of the carbon.

scholarly journals Mariner 6: Ultraviolet spectrum of Mars upper atmosphere

1971 ◽  
Vol 40 ◽  
pp. 253-256 ◽  
Author(s):  
C. A. Barth ◽  
W. G. Fastie ◽  
C. W. Hord ◽  
J. B. Pearce ◽  
K. K. Kelly ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Spectral Region ◽  
Atomic Hydrogen ◽  
Atomic Oxygen ◽  
Ultraviolet Spectrum ◽  
Upper Atmosphere

Emission features from ionized carbon dioxide and carbon monoxide were measured in the 1900- to 4300-Å spectral region. The Lyman-α 1216-Å line of atomic hydrogen and the 1304-, 1356-, and 2972-Å lines of atomic oxygen were observed.

scholarly journals Atomic Oxygen Treatment Technique for Removal of Smoke Damage From Paintings

1996 ◽  
Vol 462 ◽  
Author(s):  
S.K. Rutledge ◽  
B.A. Banks
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Optical Microscopy ◽  
Atomic Oxygen ◽  
Reflectance Spectroscopy ◽  
Smoke Exposure ◽  
Treatment Technique ◽  
Oil Painting ◽  
Oxygen Treatment

ABSTRACTSoot deposits that can accumulate on surfaces of a painting during a fire can be difficult to clean from some types of paintings without damaging the underlying paint layers. A non-contact technique has been developed which can remove the soot by allowing a gas containing atomic oxygen to flow over the surface and chemically react with the soot to form carbon monoxide and carbon dioxide. The reaction is limited to the surface, so the underlying paint is not touched. The process can be controlled so that the cleaning can be stopped once the paint surface is reached. This paper describes the smoke exposure and cleaning of untreated canvas, acrylic gesso, and sections of an oil painting using this technique. The samples were characterized by optical microscopy and reflectance spectroscopy.

scholarly journals Photodissociation of Carbon Dioxide in the Mars Upper Atmosphere

1974 ◽  
Vol 29 (2) ◽  
pp. 185-188
Author(s):  
Charles A. Barth
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Atomic Oxygen ◽  
Emission Rate ◽  
Upper Atmosphere ◽  
Emission Rates ◽  
Laboratory Measurements

Photodissociation of carbon dioxide produces O (1S) atoms and CO (a3Π) molecules in the Mars upper atmosphere. Calculations of the emission rate of the atomic oxygen 2972 Å line and the carbon monoxide Cameron bands produced by the photodissociation mechanism are factors of 3 and 10, respectively, smaller than the emission rates observed by Mariner ultraviolet spectrometers. Laboratory measurements are needed to understand the discrepancies.

scholarly journals Study of the Synchrotron Photoionization Oxidation of Alpha-Angelica Lactone (AAL) Initiated by O(3P) at 298, 550, and 700 K

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4070
Author(s):  
Golbon Rezaei ◽  
Giovanni Meloni
Keyword(s):  
Atomic Oxygen ◽  
Fossil Fuels ◽  
Reaction Products ◽  
Photoionization Mass Spectrometry ◽  
Natural Substances ◽  
Primary Products ◽  
Major Reaction ◽  
Angelica Lactone ◽  
Significant Attention

In recent years, biofuels have been receiving significant attention because of their potential for decreasing carbon emissions and providing a long-term renewable solution to unsustainable fossil fuels. Currently, lactones are some of the alternatives being produced. Many lactones occur in a range of natural substances and have many advantages over bioethanol. In this study, the oxidation of alpha-angelica lactone initiated by ground-state atomic oxygen, O(3P), was studied at 298, 550, and 700 K using synchrotron radiation coupled with multiplexed photoionization mass spectrometry at the Lawrence Berkeley National Lab (LBNL). Photoionization spectra and kinetic time traces were measured to identify the primary products. Ketene, acetaldehyde, methyl vinyl ketone, methylglyoxal, dimethyl glyoxal, and 5-methyl-2,4-furandione were characterized as major reaction products, with ketene being the most abundant at all three temperatures. Possible reaction pathways for the formation of the observed primary products were computed using the CBS–QB3 composite method.

scholarly journals Controlled atmosphere GMAW welding of transportation vehicles and production machines parts made from 30MnB5 steel

2018 ◽  
Vol 216 ◽  
pp. 03001 ◽  
Author(s):  
Evgeny Ivanayskiy ◽  
Aleksei Ishkov ◽  
Aleksandr Ivanayskiy ◽  
Iakov Ochakovskii
Keyword(s):  
Mechanical Properties ◽  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Chemical Composition ◽  
Controlled Atmosphere ◽  
Shielding Gas ◽  
Reducing Atmosphere ◽  
Metal Composition ◽  
Gmaw Welding ◽  
Welding Materials

The paper studies the influence of shielding gas on the composition and the structure of weld joint metal of 30MnB5 steel applied in essential parts of automobiles and tractors. The welding was performed in inert, oxidizing and reducing atmospheres. It was established that TIG welding with argon used as shielding gas did not provide the required mechanical properties when using conventional welding materials. Carbon dioxide during MAG welding caused partial burning of alloying elements. Carbon monoxide used as shielding gas was proved to form reducing atmosphere enabling to obtain chemical composition close to the base metal composition. Metallographic examinations were carried out. The obtained results provided full-strength weld, as well as the required reliability and durability of welded components and joints.

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