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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Ionic coupling to plasma polymer surfaces

Mutton, Simon James January 2000 (has links)
The work in this thesis was aimed at the preparation of low energy surfaces via the surface attachment of fluorinated surfactant molecules. Such surface functionalisation routes are highly dependent on the chemical nature of the substrate surface. For this reason the choice of substrate materials is both all important and extremely limited. To make the process of more general appeal a method for pre-treating the substrate, using cold plasma polymerisation reactions, followed by surfactant coupling to the plasma polymer has been devised. Using this approach, the surfactant coupling process is now dependent on the surface chemistry of deposited plasma polymers and independent of substrate characteristics. In order to form highly functionalised surfaces, likely to undergo further reactions, the plasma polymerisation of acrylic acid, ally! amine and allyl alcohol was investigated. Highly functionalised acid, amine and alcohol surfaces, as shown by X-ray Photoelectron Spectroscopy (XPS) and Infrared Spectroscopy (IR), were produced by optimisation of pulsed plasma conditions. Measurement of deposition rates during plasma polymerisation reactions indicated that polymerisation can occur during the off-time of the pulsed plasma period, most likely via free radical polymerisation pathways. Highly functionalised plasma polymer surfaces thus formed were shown to couple to fluorinated surfactant molecules. The mechanism of surfactant attachment has been suggested to be ionic attraction between opposite charges on the surfactant molecule and the plasma polymer in aqueous solution. The surfaces formed give rise to oleophobic/hydrophilic behaviour. This is in marked contrast to the usual liquid repellent attributes of conventional polyelectrolyte- fluorosurfactant complexes formed by solution phase synthesis.
492

An experimental study of state selective electron capture by state prepared low energy (<25 keV amu'-'1) ions in atomic and molecular hydrogen

Voulot, Didier January 2000 (has links)
No description available.
493

Ion-atom collisions at relativistic and non-relativistic energies

Lee, R. J. S. January 2001 (has links)
No description available.
494

Projected implications of climate change for rainfall-related crash risk

Hambly, Derrick Jackson January 2011 (has links)
It has been well established in previous research that driving during rainfall is associated with increased risk of traffic collision involvement. Of particular concern are heavy rain events, which result in elevated risks up to three times higher than those for light rainfalls. As the global climate changes in the coming century, altered precipitation patterns are likely. The primary objective of this thesis is to estimate the potential impacts of climate change on traffic safety in two large Canadian urban regions: the Greater Toronto Area and Greater Vancouver. A secondary objective is to provide a framework or methodology for exploring this question. In accomplishing the primary objective, daily collision and climate records are utilized to establish an empirical estimate of present-day rainfall-related crash risk. This estimate is combined with results of a climate modelling exercise to arrive at a possible traffic safety future for urban Canada over the next 40 years. For the second objective, several important decisions related to data acquisition, compatibility, and completeness are considered, and the tradeoffs are mapped out and discussed, in order to provide guidance for future studies. Results indicate that over the next 40 years, Toronto is likely to see a mean annual increase in rain days of all intensities, resulting in marginally more collisions and casualties each year. Substantially more rainfall days are projected for Vancouver by mid-century, resulting in a small increase in annual incident counts. In both study regions, the greatest adverse safety impact is likely to be associated with moderate to heavy rainfall days (≥ 10 mm); this estimate is consistent with the greater risk increases associated with these conditions today, and suggests that attention should be paid to future changes in the frequency and intensity of extreme rainfall events. Indeed, heavy rain days are likely to account for approximately half of all additional collision and casualty incidents.
495

Inelastic collision and three-body recombination

Li, Bo 19 May 2009 (has links)
The quantum impulse approximation theory has been extended to the inelastic collision. The total inelastic cross sections for the degenerated states with different angular momenta was calculated. It was proved that summing over the transitions from nl to n' and from nl to n'l' would give us the total cross section of transition from n to n'. Rate coefficients were calculated for the common gases in the atmosphere being the third particle. The resonant effect of the rate coefficients had been observed. Recombination coefficients were then calculated in terms of rate coefficients. Previous calculations were carried out in compare with the net rate flow through certain excited levels, which were found to be more stable and reflected a clearer picture of the whole process. Results have been compared with the elastic collision. A dramatic decreasing of rates when temperature increased was also observed. More thermal energy increases the probability of electrons for being re-ionized. Similar calculations had been carried out for the upper atmosphere gases, such as N₂, O₂, CO, CO₂, and H₂O. The recombination coefficients for electron combining with metallic ion Na+ were also calculated.
496

Deep inelastic scattering and bag model / Anthony Ian Signal

Signal, Anthony Ian January 1988 (has links)
Typescript / Copies of three papers (2 published), co-authored by the author, in back / Bibliography: leaves 179-186 / ix, 186 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1988
497

Studies in collisional energy transfer of highly rotationally and vibrationally excited molecules / Trevor C. Brown. / Studies in collisional energy transfer of highly excited molecules.

Brown, Trevor C. January 1988 (has links)
Typescript (Processed) / Errata slip inserted. / Spine title: Studies in collisional energy transfer of highly excited molecules. / Bibliography: leaves 143-167. / viii, 169 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis describes the studies made on several unimolecular reaction systems in order to obtain collisional energy transfer information on highly excited polyatomic molecules. Pressure-dependant very low-pressure pyrolysis (VLPP) and infrared multiphoton decomposition (IRMPD) experimental techniques are used. / Thesis (Ph.D.)--University of Adelaide, 1989
498

Complete numerical solution of electron-hydrogen collisions

bartlett@fizzy.murdoch.edu.au, Philip Lindsay Bartlett January 2005 (has links)
This thesis presents an extensive computational study of electron-impact scattering and ionisation of atomic hydrogen and hydrogenic ions, which are fundamental to many diverse disciplines, from astrophysics and nuclear fusion to atmospheric physics. The non-relativistic Schrodinger equation describes these collisions, though finding solutions for even hydrogen, the simplest electron-atom collision, has proven to be a monumental task. Recently, Rescigno et al [Science 286, 2474 (1999)] solved this equation in coordinate space using exterior complex scaling (ECS), and presented the first electron-hydrogen differential cross sections for ionisation that matched with experiment without requiring uncontrolled approximation. This method has significant potential for extension to larger collision systems, but its large computational demand has limited its energy range and target configurations, and its application to discrete final-state collisions has been largely unexplored. Using radically different numerical algorithms, this thesis develops methods that improve the computational efficiency of ECS by two orders of magnitude. It extends the method to calculate discrete final-state scattering cross sections and enhances the target description to include hydrogenic ions and excited initial states. In combination, these developments allow accurate solutions over a broad range of energies and targets, for both scattering and ionisation, including the important near-threshold energy region where accurate calculations have been unavailable. The refined ECS method implemented in this work now offers complete numerical solutions of electron-hydrogen collisions, and its computational efficiency will facilitate its future application to more complex targets. The thesis culminates with the first ab initio quantum mechanical confirmation of ionisation threshold laws for electron-hydrogen collisions [Bartlett and Stelbovics, 2004, Phys. Rev. Lett. 93, 233201], which have resisted confirmation through the complete solution of the Schrodinger equation for more than half a century.
499

Deep inelastic scattering and the EMC effect /

Dunne, Gerald V. January 1986 (has links) (PDF)
Thesis (M. Sc.)--University of Adelaide, Dept of Physics, 1986. / Includes bibliographical references (leaves 103-105).
500

Measurement of inclusive forward neutral pion production in 200 GeV polarized proton-proton collisions at RHIC

Wang, Yiqun, Hoffmann, Gerald W., Moore, C. Fred, January 2004 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisors: Jerry Hoffmann and C. Fred Moore. Vita. Includes bibliographical references.

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