Kinetics of Hydroxyl Radical Reactions at Low Temperatures
Author : Paul Sharkey
Publisher :
Page : pages
File Size : 18,22 MB
Release : 1993
Category :
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Author : Paul Sharkey
Publisher :
Page : pages
File Size : 18,22 MB
Release : 1993
Category :
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Author : Robin Joseph Shannon
Publisher :
Page : 285 pages
File Size : 41,31 MB
Release : 2012
Category :
ISBN :
In this thesis low temperature rate coefficients have been measured for a number of reactions involving the OH radical using a pulsed Laval nozzle apparatus. All these reactions exhibit an energy barrier between reactants and products and in each case this barrier is preceded by either a hydrogen bonded complex ( OH + acetone, OH + DME, OH + methanol) or a weaker Van der Walls complex (OH + acetylene, OH + ammonia). The rate coefficients for these reactions are observed to increase by up to three orders of magnitude between 200 K and 63 K and complimentary Master equation calculations are able to reproduce the complicated temperature dependences that these rate coefficients exhibit. From these master equation calculations, the negative temperature dependencies of the measured rate coefficients are attributed to a mechanism involving the prereaction complex, in most cases including a contribution from quantum mechanical tunnelling. This tunnelling contribution is most especially important in the case of OH + methanol and in this case, hydrogen abstraction products through a 15 kJ mol-1 barrier are observed directly at 79 K on the same timescale as OH loss. The association between an OH radical and its co-reagent to form a weakly bound adduct, is further explored through performing the first proxy method experiments below 200 K. The proxy method is designed to give the high pressure limiting rate coefficient for two associating reactants A and B through measuring the rate coefficients for the A(v=i ) + B reaction. The reactions listed above are revisited and OH vibrational levels up to v = 3 are probed. From these measurements, lower limits for the high pressure limiting rate coefficients of these reactions are obtained at 80 K and the validity of the proxy method is explored in each case.
Author : Roger Atkinson
Publisher : American Institute of Physics
Page : 270 pages
File Size : 27,80 MB
Release : 1989
Category : Science
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Author : Edgar L. Wong
Publisher :
Page : 28 pages
File Size : 21,16 MB
Release : 1970
Category : Combustion
ISBN :
Author : Yi-wen Huang
Publisher :
Page : 278 pages
File Size : 38,14 MB
Release : 2010
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A problem in the decay plot origin limits the ability to acquire data at low temperatures. The cause of the problem is probed with isotopically-labeled experiments, kinetics experiments under different flow conditions, and data analysis. A bias in acetic acid monomer concentration due to the radial temperature gradient is the most likely explanation. The problem can be corrected by using the dimer concentration to infer the monomer concentration in the core of the flow. Conclusions and future research directions are discussed in the final chapter.
Author : Charlotte Ann Whelan
Publisher :
Page : pages
File Size : 20,18 MB
Release : 2019
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Author : Hajime Akimoto
Publisher : Springer
Page : 448 pages
File Size : 47,55 MB
Release : 2016-03-04
Category : Science
ISBN : 4431558705
This book is aimed at graduate students and research scientists interested in gaining a deeper understanding of atmospheric chemistry, fundamental photochemistry, and gas phase and heterogeneous reaction kinetics. It also provides all necessary spectroscopic and kinetic data, which should be useful as reference sources for research scientists in atmospheric chemistry. As an application of reaction chemistry, it provides chapters on tropospheric and stratospheric reaction chemistry, covering tropospheric ozone and photochemical oxidant formation, stratospheric ozone depletion and sulfur chemistry related to acid deposition and the stratospheric aerosol layer. This book is intended not only for students of chemistry but also particularly for non-chemistry students who are studying meteorology, radiation physics, engineering, and ecology/biology and who wish to find a useful source on reaction chemistry.
Author : Pastrana V. Andres
Publisher :
Page : 0 pages
File Size : 26,34 MB
Release : 1973
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Author : Andrés Pastrana Arango
Publisher :
Page : 318 pages
File Size : 42,30 MB
Release : 1973
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Author : Heidi Lynn Bethel
Publisher :
Page : 414 pages
File Size : 19,11 MB
Release : 2002
Category : Hydroxyl group
ISBN :