Download or read book Laser induced fluorescence detection of HCO produced by laser photolysis of formaldehyde written by Roland König and published by . This book was released on 1982 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In situ Laser Induced Fluorescence Detection and Modeling of Formaldehyde Above a Forest Canopy written by John Robert Hottle and published by . This book was released on 2009 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Resolution Studies of the 1A2 X 1A1Electronic Transition of Formaldehyde written by Cheryl Tatum Ernest and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Formaldehyde (HCHO) plays a primary role in tropospheric chemistry. Its photochemical activity is an important source of radical species such as HCO, H, and subsequently HO2 as well as molecular hydrogen and carbon monoxide. As a source of hydrogen radicals (HOx = OH + HO2), HCHO plays a significant role in the oxidative capacity of the atmosphere, and an important part in the interrelated chemistries of ozone and the HOx and NOx (NO + NO2) cycles. Accurate atmospheric photolysis rates of HCHO are thus required in order to properly model tropospheric chemistry. Despite extensive studies HCHO's spectroscopy and photochemistry remains to be well characterized. Absolute room temperature absorption cross sections for the A1A2 -- X1A1 electronic transition of formaldehyde have been measured over the spectral range 30285 -- 32890 cm-1 (304 -- 330 nm) using ultraviolet (UV) laser absorption spectroscopy. Absorption cross sections were obtained at an instrumental resolution better than 0.09 cm-1 which is slightly broader than the Doppler width of a rotational line of HCHO at 300K (~0.07 cm-1) and so we were able to resolve all but the most closely spaced lines. Qualitative comparisons with spectral simulations show varying agreement depending on vibronic band. Refined state origins and transition dipole moments for each vibronic band have been reported. There is evidence of areas of perturbation and the need to optimize higher order spectral constants. Pressure broadening parameters have been measured and increase with the strength of intermolecular interaction between formaldehyde and the collision partner. Comparisons between the available high-resolution studies and spectral simulations indicate that the HCHO absorption cross section is still not well characterized. The relative quantum yield for the production of radical products, H+HCO, from the UV photolysis of formaldehyde (HCHO) has been measured directly using a Pulsed Laser Photolysis -- Pulsed Laser Induced Fluorescence (PLP -- PLIF) technique across the same spectral region. Relative yields were normalized to a value of 0.69 at 31750 cm-1 based on the current NASA-JPL recommendation. The resulting absolute radical quantum yields agree well with previous experimental studies and show more wavelength dependent behavior than the recommendation. This provides support for the complicated competition among the various HCHO dissociation pathways.

Download or read book Aldehydes Advances in Research and Application 2013 Edition written by and published by ScholarlyEditions. This book was released on 2013-06-21 with total page 941 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aldehydes—Advances in Research and Application: 2013 Edition is a ScholarlyEditions™ book that delivers timely, authoritative, and comprehensive information about Acetaldehyde. The editors have built Aldehydes—Advances in Research and Application: 2013 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Acetaldehyde in this book to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Aldehydes—Advances in Research and Application: 2013 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book Laser Spectroscopy Sensors for Measurement of Trace Gaseous Formaldehyde written by Ravi Kumar Boddeti and published by . This book was released on 2008 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: A sensitive and direct method to determine atmospheric formaldehyde (HCHO) using laser induced fluorescence spectroscopy (LIF) is described. This technique overcomes the tedious sample collections, water extraction and chemical reactions that are often required in conventional methods. In this LIF approach, the third harmonic of a nontunable Nd:YAG laser at 355 nm is used as a selective excitation wavelength for formaldehyde. Studies at alternative excitation wavelengths have also been performed using 341 nm and 309 nm, which are obtained by Stimulated Raman Scattering of nontunable Nd:YAG laser radiation at 266 nm and 355 nm, respectively. The calibration response is linear in the range of 1-57 ppm and the current limit of detection (LOD) is 0.5 ppm HCHO. It is anticipated that these approaches may be able to avoid interferences that occur in conventional methods for HCHO measurements.

Download or read book Formaldehyde as a Tracer to Examine Mixture Formation in Spark Ignited Engines written by Aulia Muhammad Taufiq Nasution and published by Cuvillier Verlag. This book was released on 2006 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography on the High Temperature Chemistry and Physics of Materials written by and published by . This book was released on 1991 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Investigation of Nitrogen Laser Induced Fluorescence in Formaldehyde Spectra and Spectrally Resolved Lifetimes written by Ralph Ernest Chatham and published by . This book was released on 1977 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a considerable interest in the lifetimes and predissociation mechanisms of the excited formaldehyde molecule, H2CO. Active research is being conducted in the use of this predissociation via selective laser excitation to separate various isotopes of the three atomic species which make up the molecule. In addition, the molecule's comparatively simple structure and a large body of experimental data concerning that structure make it a useful test case for theoretical models. There are also astrophysical applications. The fact that light in the near ultraviolet causes dissociation of formaldehyde with a quantum yield which is close to one makes the molecule a sensitive detector of the radiation environment in the dense interstellar molecular clouds in which it has been observed by radio astronomy. (Author).

Download or read book Laser Applications to Chemical Dynamics written by Mustafa A. El-Sayed and published by . This book was released on 1987 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Investigation of Nitrogen Laser Induced Fluorescence in Formaldehyde Spectra and Spectrally Resolved Lifetimes written by and published by . This book was released on 1977 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: There is a considerable interest in the lifetimes and predissociation mechanisms of the excited formaldehyde molecule, H2CO. Active research is being conducted in the use of this predissociation via selective laser excitation to separate various isotopes of the three atomic species which make up the molecule. In addition, the molecule's comparatively simple structure and a large body of experimental data concerning that structure make it a useful test case for theoretical models. There are also astrophysical applications. The fact that light in the near ultraviolet causes dissociation of formaldehyde with a quantum yield which is close to one makes the molecule a sensitive detector of the radiation environment in the dense interstellar molecular clouds in which it has been observed by radio astronomy. (Author).

Download or read book Laser Induced Fluorescence Measurements of Formaldehyde in a Methane Air Diffusion Flame written by J. E. Harrington and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Investigations of Nitrogen Laser Induced Fluorescence in Formaldehyde written by Ralph Ernest Chatham and published by . This book was released on 1977 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photochemistry written by D. Bryce-Smith and published by Royal Society of Chemistry. This book was released on 1981 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation The breadth of scientific and technological interests in the general topic of photochemistry is truly enormous and includes, for example, such diverse areas as microelectronics, atmospheric chemistry, organic synthesis, non-conventional photoimaging, photosynthesis, solar energy conversion, polymer technologies, and spectroscopy. This Specialist Periodical Report on Photochemistry aims to provide an annual review of photo-induced processes that have relevance to the above wide-ranging academic and commercial disciplines, and interests in chemistry, physics, biology and technology. In order to provide easy access to this vast and varied literature, each volume of Photochemistry comprises sections concerned with photophysical processes in condensed phases, organic aspects which are sub-divided by chromophore type, polymer photochemistry, and photochemical aspects of solar energy conversion. Volume 34 covers literature published from July 2001 to June 2002. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.

Download or read book Physics Briefs written by and published by . This book was released on 1990 with total page 1394 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Formaldehyde Instrument Development and Boundary Layer Sulfuric Acid Implications for Photochemistry written by Anne Theresa Case Hanks and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents the development of a laser-induced fluorescence technique to measure atmospheric formaldehyde. In conjunction with the technique, the design of a compact, narrow linewidth, etalon-tuned titanium:sapphire laser cavity which is pumped by the second harmonic of a kilohertz Nd:YAG laser is also presented. The fundamental tunable range is from 690-1100 nm depending on mirror reflectivities and optics kit used. The conversion efficiency is at least 25% for the fundamental, and 2-3% for intracavity frequency doubling from 3.5-4W 532 nm pump power. The linewidth is

Download or read book Determination of Nascent Hydrogen Rovibrational Distributions by Laser induced Fluorescence written by Garth Rockwood Jr Parker and published by . This book was released on 1988 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Determination of Nascent H2 Rovibrational Distributions by Laser Induced Fluorescence Applications to Formaldehyde Photodissociation and Hydrogen Exchange Reactions written by Garth Rockwood Parker and published by . This book was released on 1988 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: