Since 1950's there has been a growing interest of understanding the effects of cosmic ray radiation on the increase in average global temperature. Recent studies showed that galactic cosmic rays play a significant role in the formation of low cloud coverage and its consequent impact on the global temperature variation of the earth. A long-term measurement of the cosmic ray flux distribution at the surface of the earth has been established at Georgia State University. The current effort is focused on understanding the correlations between the cosmic ray particle flux distribution and the atmospheric and space weather measurements. In order to understand the observed atmospheric effects on cosmic ray flux, numerical simulations of cosmic muon and neutron flux variations at the surface of the earth have been carried out with varying air densities in the troposphere and stratosphere based on the Geant4 package. The simulation results show a remarkably good agreement with observations. The simulation results also show that the stratosphere air density variation dominates the effects on the muon flux changes while the density variation in the troposphere mainly influences the neutron count variation. This suggests that the long-term variation of muon flux could possibly direct us to a new path to understand the global climate warming trend.

One of the remaining problems associated with the photo-degradation of organic species in the atmosphere, is concerned with the mechanisms of C₅ and larger fragments. In this respect the 2-pentoxy radical has been chosen as a model radical. The subsequent mechanisms for it are thought to be similar to those for all other larger species. The photolysis of 2-pentyl nitrite in the near ultraviolet (UV) region at 328-383 nm resulted in the formation of 2-pentoxy radicals and nitric oxide with the quantum yield of 0.97 ± 0.08 at 298-393K, consistent with the assumption that the quantum yield was unity for alkyl nitrites. In the present work, <I>tert-</I>butyl nitrite has been shown to be unity. The reactions of the model radical were investigated in inert (CF₄), and oxygen atmospheres, by end product analysis using on-line gas-liquid chromatography. The expected reaction routes were: decomposition, oxidation (β-H atom abstraction), and 1,5-H shift isomerisation which would produce acetaldehyde, 2-pentanone and acetone respectively. Its reaction scheme was evaluated by comparing the experimental with model results, derived by the Gear Algorithm. The estimated or calculated rate constants in the literature were "brute force" adjusted to adapt the modelling results to the experimental results. Our investigations suggested, among the rate constants for the 2-pentoxy radical: k_dec9.2 x 10³s^-1: CH₃CH(O)(CH₂)₂CH₃ → n-CH₃CHO + n-C₃H_7,k₀₂ 7.0 x 10⁵M^-1s^-1: CH₃CH(O)(CH₂)₂CH₃+0₂ → CH₃C(O)(CH₂)₂CH₃ + HO₂, and k_isom 1.4 x 10⁴s^-1; CH₃CH(O)(CH₂)₂CH₃ → CH₃CH(OH)(CH₂)₂CH₂) The 1,5-H shift isomerisation is relatively fast. The Arrhenius parameters of these rate constants were also modified.

Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on March 26, 2008) Includes bibliographical references.

Thesis (Ph.D.) -- McMaster University, 1997. / Includes bibliographical references. Also available via World Wide Web.

Thesis (M Arch)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Christopher Livingston. Includes bibliographical references (leaves 97-99).

Final Project (M.A.)--John F. Kennedy University, 2005. / "August 29, 2005"--T.p. Includes bibliographical references (p. 136-141).

Thesis (LL.M.)--University of Calgary (Canada), 2004. / Adviser: Alastair Lucas. Includes bibliographical references.

Thesis.

Thesis (D. Tech.)--Helsinki University of Technology, 1998. / Issued also in electronic form.

Thesis (Ph. D.)--Queen's University, 1993. / Vita. Includes bibliographical references (leaves 222-238).