Download or read book Laser Induced Fluorescence of Hydroxyl OH Radical in Cold Atmospheric Discharges written by Jan Voráč and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of laser-induced fluorescence (LIF) to measurement of absolute concentration of hydroxyl radicals in cold atmospheric discharges is described. Though only the case of OH is presented, the method can be directly applied to other molecules as well. Starting from the rate equations for the LIF process, the main formulas for two- and multi-level excitation scheme are derived. It is also shown how to use partially saturated LIF in practice, enhancing the signal-to-noise ratio. Practical tips for automating the data evaluation are given, allowing processing large data sets, particularly suitable for planar measurements. Gas temperature estimation from fluorescence on different rotational absorption lines is shown as an attractive method for obtaining temperature maps with high spatial resolution. The important aspects of calibration are discussed, particularly the overlap of the laser line with the selected absorption line and the measurement of the Rayleigh scattering for sensitivity calibration, together with the common sources of errors. The application of OH(A, v' = 0 ← X, v" = 0) excitation scheme to the effluent of atmospheric pressure plasma jet ignited in argon and of OH(A, v' = 1 ← X, v" = 0) to the plasma of coplanar surface barrier discharge in air and in water vapor is shown.
Download or read book Reactions of Hydroxyl Radicals with Oxygenated Hydrocarbons in the Gas Phase A Laser Photolysis Laser Induced Fluorescence Study written by Cornelie Bänsch and published by Logos Verlag Berlin GmbH. This book was released on 2017 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydroxyl radicals (OH) play a key role in ignition processes and in the atmosphere. Thus, the detailed knowledge of the kinetics of OH reactions is crucial in combustion and atmospheric research. In this work, an experimental approach for time-resolved studies of OH radical reactions at high pressures with pulsed laser photolysis/laser-induced fluorescence was revised and the reactions of dimethyl ether, diethyl ether, and dimethoxymethane with OH radicals were investigated in detail. The results reveal a deeper insight into the reaction processes of ether compounds with OH in general, contributing to a better understanding of the combustion of different biofuels and fuel additives.
Download or read book Photon Counting written by Nikolay Britun and published by BoD – Books on Demand. This book was released on 2018-03-21 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photon counting is a unified name for the techniques using single-photon detection for accumulative measurements of the light flux, normally occurring under extremely low-light conditions. Nowadays, this approach can be applied to the wide variety of the radiation wavelengths, starting from X-ray and deep ultraviolet transitions and ending with far-infrared part of the spectrum. As a special tribute to the photon counting, the studies of cosmic microwave background radiation in astronomy, the experiments with muon detection, and the large-scale fundamental experiments on the nature of matter should be noted. The book provides readers with an overview on the fundamentals and state-of-the-art applications of photon counting technique in the applied science and everyday life.
Download or read book Laser Induced Fluorescence LIF Spectroscopic Measurement of Hydroxyl OH Radical Concentration Near Surfaces with Varying Chemical and Thermal Activity in Low Pressure Stoichiometric Hydrogen oxygen Flames written by Shaurya Prakash and published by . This book was released on 2003 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A laser induced fluorescence study of OH radical desorption in the H 2 O 2 reaction on Pt written by T. Wahnström and published by . This book was released on 1989 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Collisional and Radiative Processes of the Hydroxyl Radical written by Kristen Lisa Steffens and published by . This book was released on 1994 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book LIF Diagnostics of Hydroxyl Radical in a Methanol Containing Atmospheric pressure Plasma Jet Project Supported by the National Natural Science Foundation of China Grant Nos 11465013 and 11375041 the Natural Science Foundation of Jiangxi Province China Grant Nos 20151BAB212012 and 20161BAB201013 and the International Science and Technology Cooperation Program of China Grant No 2015DFA61800 written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this paper, a pulsed-dc CH3 OH/Ar plasma jet generated at atmospheric pressure is studied by laser-induced fluorescence (LIF) and optical emission spectroscopy (OES). A gas–liquid bubbler system is proposed to introduce the methanol vapor into the argon gas, and the CH3 OH/Ar volume ratio is kept constant at about 0.1%. Discharge occurs in a 6-mm needle-to-ring gap in an atmospheric-pressure CH3 OH/Ar mixture. The space-resolved distributions of OH LIF inside and outside the nozzle exhibit distinctly different behaviors. And, different production mechanisms of OH radicals in the needle-to-ring discharge gap and afterglow of plasma jet are discussed. Besides, the optical emission lines of carbonaceous species, such as CH, CN, and C2 radicals, are identified in the CH3 OH/Ar plasma jet. Finally, the influences of operating parameters (applied voltage magnitude, pulse frequency, pulsewidth) on the OH radical density are also presented and analyzed.
Download or read book Laser induced Fluorescence of the Hydroxyl Radical written by Zhongbin Yin and published by . This book was released on 1993 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetic Studies of the Reactions of Hydroxyl OH Radicals with Hydrogen containing Chlorofluorocarbons HCFC Over an Extended Temperature Range Using a Laser Photolysis laser induced Fluorescence Technique written by Tunchen Daniel Fang and published by . This book was released on 1996 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quantitative Measurement of Hydroxyl Radical OH Concentration in Premixed Flat Flame by Combining Laser induced Fluorescence and Direct Absorption Spectroscopy Project Supported by the National Natural Science Foundation of China Grant No 11272338 the Science and Technology on Scramjet Key Laboratory Funding China Grant No STSKFKT 2013004 and the China Scholarship Council written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: An accurate and reasonable technique combining direct absorption spectroscopy and laser-induced fluorescence (LIF) methods is developed to quantitatively measure the concentrations of hydroxyl in CH4 /air flat laminar flame. In our approach, particular attention is paid to the linear laser-induced fluorescence and absorption processes, and experimental details as well. Through measuring the temperature, LIF signal distribution and integrated absorption, spatially absolute OH concentrations profiles are successfully resolved. These experimental results are then compared with the numerical simulation. It is proved that the good quality of the results implies that this method is suitable for calibrating the OH-PLIF measurement in a practical combustor.
Download or read book Laser Induced Hydroxyl Radical Fluoresence at Atmospheric Pressure written by Cornelius Yuk-kwan Chan and published by . This book was released on 1982 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetic Study of Reactions with Interest to Atmospheric Chemistry by Simultaneous Detection of OH and RO2 Radicals Coupled to Laser Photolysis written by Emmanuel Assaf and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hydroxyl radical OH and hydroperoxy radical HO2 radicals are key species in many oxidation processes in the atmosphere. The degradation of volatile organic compounds under tropospheric conditions is induced by reactions with hydroxyl radicals followed by the subsequent chemistry of the initial OH oxidation products with O2. This thesis was focused on the kinetic study of some of these atmospherically relevant reactions to better understand their oxidation mechanisms using an experimental system of laser photolysis coupled to Laser Induced Fluorescence (LIF, for OH radical) and continuous-wave Cavity Ring-Down Spectroscopy (cw-CRDS, for OH, HO2 and RO2 radicals) detection techniques. After determining the infrared spectrum of OH, HO2 and CH3O2 radicals in the near infrared region and the absorption cross-sections of few selected lines, four systems were studied with the above mentioned techniques: CH3O2 + OH, C2H5O2 + OH, C3H7O2 + OH and C4H9O2 + OH. The rate constant and the HO2 yield of the four reactions were determined. In addition, the rate constants of few secondary reactions such as CH3O + HO2, CH3O + CH3O or OH + HO2 have been determined.
Download or read book Development of a Two Photon laser Induced Fluorescence Technique for the Detection of Atmospheric OH Radicals written by John Bradshaw and published by . This book was released on 1990 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Two photon laser Induced Fluorescence Sensor for the Detection of Atmospheric OH Radicals written by John David Bradshaw and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Peroxy Radicals Using Laser Induced Fluorescence Technique written by Hendrik Fuchs and published by . This book was released on 2006 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scattering of state selected and oriented hydroxyl radicals by halogen hydrides and xenon written by Angelica Valentina Moise and published by . This book was released on 2007 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Induced Fluorescence Spectroscopy of the Hydroxyl and Methoxy Radicals written by Abdullahi H. Nur and published by . This book was released on 1991 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
