+publisher:"Georgia Tech" +contributor:("Paul Wine")

1. Huskey, Dow T. A temperature and pressure dependent kinetics study of the gas-phase reactions of bromine (2P3/2) and chlorine (2PJ) atoms with methylvinyl ketone.

Degree: MS, Chemistry and Biochemistry, 2008, Georgia Tech

URL: http://hdl.handle.net/1853/24734

► A laser flash photolysis resonance fluorescence (LFP-RF) technique has been employed to study the kinetics of the reactions of methylvinyl ketone (MVK) with atomic bromine… (more)

▼ A laser flash photolysis resonance fluorescence (LFP-RF) technique has been employed to study the kinetics of the reactions of methylvinyl ketone (MVK) with atomic bromine (Br) and atomic chlorine (Cl) as a function of temperature (203 755 K) and pressure (12 600 Torr) in nitrogen bath gas. The results of this study are also compared to published kinetics studies for similar reactions. Over the temperature range 200 K < T < 250 K for the reaction of Br with MVK, measured rate coefficients were pressure dependent suggesting the formation of an adduct. The adduct undergoes dissociation on the time scale of the experiments (< 0.1 s) and establishes an equilibrium between Br, MVK, and MVK Br. At temperatures above 298 K no reaction of Br with MVK was observed. Similarly, over the temperature range 405 K < T < 510 K, the reaction of Cl with MVK shows similar kinetics to that of Br and MVK suggesting an equilibrium is established. Equilibrium constants for adduct dissociation and formation are determined for the forward and reverse rate coefficients in both reactions. Second and third-law analyses are carried out to obtain information about the thermochemistry of the equilibrium reactions for Br with MVK and Cl with MVK. Adduct bond strengths of Br and Cl reactions with MVK are reported and compared to reactions with other unsaturated species. Ab initio calculations for these reactions are also presented in this study. Excellent agreement is observed between theory and experiment. Additionally, a reaction of Cl with MVK was observed over the temperature ranges 600 K < T < 760 K and 210 K < T < 365 K. At the lower temperatures, measured rate coefficients are also pressure dependent, however, the adduct remained stable. At the highest temperatures, the measured rate coefficients were pressure independent, suggesting hydrogen abstraction as the dominant reaction pathway. Energetics obtained from ab initio calculations suggest that only abstraction of the methyl hydrogen is likely to occur at a measurable rate in the temperature range investigated. Advisors/Committee Members: Dr. Paul Wine (Committee Chair), Dr. Jean-Luc Brédas (Committee Member), Dr. Rigoberto Hernandez (Committee Member).

Subjects/Keywords: Rate coefficient; Bond strength; Abstraction; Adduct; Gas phase; Kinetics; Br; Bromine; Cl; Chlorine; Ketone; Methylvinyl; Bromine; Chlorine; Ketones; Chemical kinetics; Reactivity (Chemistry)

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APA (6^th Edition):

Huskey, D. T. (2008). A temperature and pressure dependent kinetics study of the gas-phase reactions of bromine (2P3/2) and chlorine (2PJ) atoms with methylvinyl ketone. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/24734

Chicago Manual of Style (16^th Edition):

Huskey, Dow T. “A temperature and pressure dependent kinetics study of the gas-phase reactions of bromine (2P3/2) and chlorine (2PJ) atoms with methylvinyl ketone.” 2008. Masters Thesis, Georgia Tech. Accessed January 27, 2021. http://hdl.handle.net/1853/24734.

MLA Handbook (7^th Edition):

Huskey, Dow T. “A temperature and pressure dependent kinetics study of the gas-phase reactions of bromine (2P3/2) and chlorine (2PJ) atoms with methylvinyl ketone.” 2008. Web. 27 Jan 2021.

Vancouver:

Huskey DT. A temperature and pressure dependent kinetics study of the gas-phase reactions of bromine (2P3/2) and chlorine (2PJ) atoms with methylvinyl ketone. [Internet] [Masters thesis]. Georgia Tech; 2008. [cited 2021 Jan 27]. Available from: http://hdl.handle.net/1853/24734.

Council of Science Editors:

Huskey DT. A temperature and pressure dependent kinetics study of the gas-phase reactions of bromine (2P3/2) and chlorine (2PJ) atoms with methylvinyl ketone. [Masters Thesis]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/24734

2. Laine, Patrick L. Laser flash photolysis studies of halogen atom reactions of atmospheric interest.

Degree: PhD, Earth and Atmospheric Sciences, 2011, Georgia Tech

URL: http://hdl.handle.net/1853/42817

► The Earth's atmosphere is a large photochemical reactor consisting primarily of N2 (~78%) and O2 (~21%) with Ar and water vapor being the next most… (more)

▼ The Earth's atmosphere is a large photochemical reactor consisting primarily of N2 (~78%) and O2 (~21%) with Ar and water vapor being the next most abundant constituents. All of the remaining gases in the atmosphere are referred to as 'trace gases', and they play a critical role in understanding climate change, urban air quality, ozone production and depletion, and in determining the overall 'health' of the atmosphere. These trace components are present in our atmosphere with mixing ratios, i.e., mole fractions, ranging from sub parts per trillion to several hundred parts per million. One class of trace constituents that play a critical role in atmospheric chemistry are free radicals. Free radicals are highly reactive, often initiating the oxidation of natural and anthropogenic atmospheric species, thereby often controlling the fate and lifetimes of these species. The research comprising this dissertation focuses on laboratory studies of the kinetics and mechanisms of free radical (atomic halogen) reactions that can impact the levels of important trace atmospheric species. In the studies reported herein, laser flash photolysis (LFP) was coupled with time resolved atomic resonance fluorescence (RF) spectroscopic detection of Cl or Br atoms to investigate halogen atom chemistry. The research addresses three groups of reactions: Cl atom reactions with alkyl bromides, Cl and Br-initiated oxidations of small (C2-C6) alkenes, and Cl reactions with CH3SCH3 (DMS, dimethylsulfide) and CH3SeCH3 (DMSe, dimethylselenide). The alkyl bromide reactions were experimentally unique in that we were able to deduce kinetics of the Cl atom reaction with bromoethane, n-bromopropane, and 1,2-dibromoethane by monitoring the appearance of the Br product by LFP-RF. The Br is formed via elimination that occurs essentially instantaneously following β-H abstraction by the Cl atom. All three of the bromoalkanes investigated are emitted into the atmosphere primarily from anthropogenic sources and all three have been identified by the World Meteorological Organization (WMO) as very short-lived (lifetime less than 6 months) source gases with significant ozone depletion potentials (ODPs). Additionally, the bromoalkanes mentioned above have been of interest as model compounds for larger partially halogenated organics found in the atmosphere, and they have been considered as potential replacement compounds for chlorofluorocarbons (CFCs) that have been banned as a result of the Montreal Protocol. Brominated very short-lived compounds are thought to contribute 20-25% of total stratospheric bromine. Thus, there is considerable interest in understanding the atmospheric chemistry of even the most short-lived organic bromine compounds. Temporal profiles of Br atoms provided important kinetic and mechanistic insight for the reactions over a wide range of temperature and pressure. Temperature-dependent rate coefficients are determined for the alkyl bromides of interest for the first time, and the potential importance of the Cl reaction as an… Advisors/Committee Members: Paul Wine (Committee Chair), Athanasios Nenes (Committee Member), Greg Huey (Committee Member), Rodney Weber (Committee Member), Thomas Orlando (Committee Member).

Subjects/Keywords: Bromine atom reactions; Chlorine atom reactions; Halogen atoms; Gas phase reactions; Free radical reactions; Free radicals (Chemistry); Chemical reactions; Thermochemistry; Atmosphere; Atmosphere Laser observations

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APA (6^th Edition):

Laine, P. L. (2011). Laser flash photolysis studies of halogen atom reactions of atmospheric interest. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/42817

Chicago Manual of Style (16^th Edition):

Laine, Patrick L. “Laser flash photolysis studies of halogen atom reactions of atmospheric interest.” 2011. Doctoral Dissertation, Georgia Tech. Accessed January 27, 2021. http://hdl.handle.net/1853/42817.

MLA Handbook (7^th Edition):

Laine, Patrick L. “Laser flash photolysis studies of halogen atom reactions of atmospheric interest.” 2011. Web. 27 Jan 2021.

Vancouver:

Laine PL. Laser flash photolysis studies of halogen atom reactions of atmospheric interest. [Internet] [Doctoral dissertation]. Georgia Tech; 2011. [cited 2021 Jan 27]. Available from: http://hdl.handle.net/1853/42817.

Council of Science Editors:

Laine PL. Laser flash photolysis studies of halogen atom reactions of atmospheric interest. [Doctoral Dissertation]. Georgia Tech; 2011. Available from: http://hdl.handle.net/1853/42817

Georgia Tech

3. Case Hanks, Anne Theresa. Formaldehyde instrument development and boundary layer sulfuric acid: implications for photochemistry.

Degree: PhD, Earth and Atmospheric Sciences, 2008, Georgia Tech

URL: http://hdl.handle.net/1853/22683

► 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… (more)

▼ 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 < 0.1 cm-1, and the pulsewidth is 18 nsec. Also presented are observations of gas-phase sulfuric acid from the NEAQS-ITCT 2K4 (New England Air Quality Study Intercontinental Transport and Chemical Transformation) field campaign in July and August 2004. Sulfuric acid values are reported for a polluted environment and possible nucleation events as well as particle growth within the boundary layer are explored. Sulfate production rates via gas phase oxidation of sulfur dioxide are also reported. This analysis allows an important test of our ability to predict sulfuric acid concentration and probe its use as a fast time response photochemical tracer for the hydroxyl radical, OH. In comparison, the NASA time-dependent photochemical box model is used to calculate OH concentration. Nighttime H2SO4 values are examined to test our understanding of nocturnal OH levels and oxidation processes. In comparison, sulfuric acid from a large ground based mission in Tecámac, México (near the northern boundary of Mexico City) during MIRAGE-Mex field campaign (March 2006) is presented. The observations in conjunction with the NASA LARc Photochemical box model are used to explore ozone production, nitrate and sulfate formation, and radical levels and radical production rates during the day. The one minute observations of sulfuric acid, sulfur dioxide, and aerosol surface area were again used to calculate OH levels assuming steady state, and are in good agreement with observations of OH (R2 = 0.7). Photochemical activity is found to be a maximum during the morning hours, as seen in ozone and nitrate formation. Advisors/Committee Members: Greg Huey (Committee Chair), David Tan (Committee Member), Jennifer Olson (Committee Member), Paul Wine (Committee Member), Rodney Weber (Committee Member).

Subjects/Keywords: Formaldehyde; Sulfuric acid; Photochemistry; Laser; CIMS; Photochemistry; Formaldehyde – Measurement; Fluorescence spectroscopy; Lasers; Sulfuric acid; Atmospheric chemistry; Oxidation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Case Hanks, A. T. (2008). Formaldehyde instrument development and boundary layer sulfuric acid: implications for photochemistry. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/22683

Chicago Manual of Style (16^th Edition):

Case Hanks, Anne Theresa. “Formaldehyde instrument development and boundary layer sulfuric acid: implications for photochemistry.” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 27, 2021. http://hdl.handle.net/1853/22683.

MLA Handbook (7^th Edition):

Case Hanks, Anne Theresa. “Formaldehyde instrument development and boundary layer sulfuric acid: implications for photochemistry.” 2008. Web. 27 Jan 2021.

Vancouver:

Case Hanks AT. Formaldehyde instrument development and boundary layer sulfuric acid: implications for photochemistry. [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 27]. Available from: http://hdl.handle.net/1853/22683.

Council of Science Editors:

Case Hanks AT. Formaldehyde instrument development and boundary layer sulfuric acid: implications for photochemistry. [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/22683

Georgia Tech

4. Liao, Wei. LIF instrument development, in situ measurement at South Pole and 1D air-snowpack modeling of atmospheric nitrous acid (HONO).

Degree: PhD, Earth and Atmospheric Sciences, 2008, Georgia Tech

URL: http://hdl.handle.net/1853/28107

► Atmospheric nitrous acid (HONO) is a significant and sometimes dominant OH source at polar region. An improved method of detecting HONO is developed using photo-fragmentation… (more)

Subjects/Keywords: ANTCI 2003; Snowpack modeling; South Pole; LIF; HONO; Nitrous acid; Atmospheric nitrous oxide; Nitrous acid; Polar regions; Atmospheric chemistry; Photochemistry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Liao, W. (2008). LIF instrument development, in situ measurement at South Pole and 1D air-snowpack modeling of atmospheric nitrous acid (HONO). (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/28107

Chicago Manual of Style (16^th Edition):

Liao, Wei. “LIF instrument development, in situ measurement at South Pole and 1D air-snowpack modeling of atmospheric nitrous acid (HONO).” 2008. Doctoral Dissertation, Georgia Tech. Accessed January 27, 2021. http://hdl.handle.net/1853/28107.

MLA Handbook (7^th Edition):

Liao, Wei. “LIF instrument development, in situ measurement at South Pole and 1D air-snowpack modeling of atmospheric nitrous acid (HONO).” 2008. Web. 27 Jan 2021.

Vancouver:

Liao W. LIF instrument development, in situ measurement at South Pole and 1D air-snowpack modeling of atmospheric nitrous acid (HONO). [Internet] [Doctoral dissertation]. Georgia Tech; 2008. [cited 2021 Jan 27]. Available from: http://hdl.handle.net/1853/28107.

Council of Science Editors:

Liao W. LIF instrument development, in situ measurement at South Pole and 1D air-snowpack modeling of atmospheric nitrous acid (HONO). [Doctoral Dissertation]. Georgia Tech; 2008. Available from: http://hdl.handle.net/1853/28107

Georgia Tech

5. Captain, Janine Elizabeth. Non-thermal Interactions on Low Temperature Ice and Aqueous Interfaces.

Degree: PhD, Chemistry and Biochemistry, 2005, Georgia Tech

URL: http://hdl.handle.net/1853/6995

► Electron-impact ionization of low-temperature water ice leads to H+, H2+, and H+(H2O)n=1-8 desorption. The threshold energy for ESD of H2+ from CI and H3O+ from… (more)

▼ Electron-impact ionization of low-temperature water ice leads to H+, H2+, and H+(H2O)n=1-8 desorption. The threshold energy for ESD of H2+ from CI and H3O+ from PASW and ASW is 22 ± 3 eV. There is also a H2+ yield increase at 40 ± 3 eV and a 70 ± 3 eV threshold for ESD of H+(H2O)n=2-8 from PASW and ASW. H2+ production and desorption involves direct molecular elimination and reactive scattering of an energetic proton. Both of these channels likely involve localized two-hole one-electron and/or two-hole final states containing 4a1, 3a1 and/or 2a1 character. The 70 eV cluster ion threshold implicates either an initial (2a1-2) state localized on a monomer or the presence of at least two neighboring water molecules each containing a single hole. The resulting correlated two-hole or two-hole, one-electron configurations are localized within a complex and result in an intermolecular Coulomb repulsion and cluster ion ejection. The changes in the yields with phase and temperature are associated with structural and physical changes in the adsorbed water and longer lifetimes of excited state configurations containing a1 character. The dependence of the ESD cation yields on the local potential has been utilized to examine the details of HCl interactions on low temperature ice surfaces. The addition of HCl increases cluster ion yields from pure ice while decreasing H+ and H2+ yields. These changes reflect the changes in the local electronic potential due to the changing bond lengths at the surface of the ice as HCl ionizes and the surrounding water molecules reorient to solvate the ions. This work has been extended to ionic solutions at higher temperatures using a liquid jet and ultraviolet photoionization to interrogate the surface of aqueous ionic interfaces. Desorption of protonated water clusters and solvated sodium ion clusters were measured over a range of concentrations from NaCl, NaBr, and NaI solutions. The flux dependence indicated a multiple photon process and the proposed mechanism involves a Coulomb explosion resulting from the repulsion of nearby ions. The surface is investigated with regard to its importance in heterogeneous atmospheric chemistry. Advisors/Committee Members: Thomas Orlando (Committee Chair), Boris Mizaikoff (Committee Member), Greg Huey (Committee Member), Jiri Janata (Committee Member), Paul Wine (Committee Member).

Subjects/Keywords: Ice surface; Ionic interface; Electron stimulated desorption; Liquid jet

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Captain, J. E. (2005). Non-thermal Interactions on Low Temperature Ice and Aqueous Interfaces. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/6995

Chicago Manual of Style (16^th Edition):

Captain, Janine Elizabeth. “Non-thermal Interactions on Low Temperature Ice and Aqueous Interfaces.” 2005. Doctoral Dissertation, Georgia Tech. Accessed January 27, 2021. http://hdl.handle.net/1853/6995.

MLA Handbook (7^th Edition):

Captain, Janine Elizabeth. “Non-thermal Interactions on Low Temperature Ice and Aqueous Interfaces.” 2005. Web. 27 Jan 2021.

Vancouver:

Captain JE. Non-thermal Interactions on Low Temperature Ice and Aqueous Interfaces. [Internet] [Doctoral dissertation]. Georgia Tech; 2005. [cited 2021 Jan 27]. Available from: http://hdl.handle.net/1853/6995.

Council of Science Editors:

Captain JE. Non-thermal Interactions on Low Temperature Ice and Aqueous Interfaces. [Doctoral Dissertation]. Georgia Tech; 2005. Available from: http://hdl.handle.net/1853/6995

Georgia Tech

6. Sjostedt, Steven Jeffrey. Investigation of Photochemistry at High Latitudes: Comparison of model predictions to measurements of short lived species.

Degree: PhD, Earth and Atmospheric Sciences, 2006, Georgia Tech

URL: http://hdl.handle.net/1853/14109

► Recent field campaigns have measured enhanced levels of NOx (NO+NO2) and HOx precursors (i.e., H2O2, CH2O, and HONO) that can not be accounted for by… (more)

Subjects/Keywords: Nitric acid; Pernitric acid; OH; HOx; Nitric acid; Photochemistry; Atmospheric chemistry

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Sjostedt, S. J. (2006). Investigation of Photochemistry at High Latitudes: Comparison of model predictions to measurements of short lived species. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/14109

Chicago Manual of Style (16^th Edition):

Sjostedt, Steven Jeffrey. “Investigation of Photochemistry at High Latitudes: Comparison of model predictions to measurements of short lived species.” 2006. Doctoral Dissertation, Georgia Tech. Accessed January 27, 2021. http://hdl.handle.net/1853/14109.

MLA Handbook (7^th Edition):

Sjostedt, Steven Jeffrey. “Investigation of Photochemistry at High Latitudes: Comparison of model predictions to measurements of short lived species.” 2006. Web. 27 Jan 2021.

Vancouver:

Sjostedt SJ. Investigation of Photochemistry at High Latitudes: Comparison of model predictions to measurements of short lived species. [Internet] [Doctoral dissertation]. Georgia Tech; 2006. [cited 2021 Jan 27]. Available from: http://hdl.handle.net/1853/14109.

Council of Science Editors:

Sjostedt SJ. Investigation of Photochemistry at High Latitudes: Comparison of model predictions to measurements of short lived species. [Doctoral Dissertation]. Georgia Tech; 2006. Available from: http://hdl.handle.net/1853/14109

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