The mechanism of a conjugate addition of an alcohol to an alkynic acid ester using a phosphine catalyst was investigated using pressurized sample infusion electrospray ionization mass spectrometry (PSI-ESI-MS) and proton and phosphorus nuclear magnetic resonance (NMR) experiments. Since ESI-MS only detects charged species, and only the phosphonium intermediates and by-products were visible by ESI-MS, 1H NMR was used to track the disappearance of the starting alkyne and the appearance of the conjugate addition product over time. 31P NMR was used to quantify the ESI-MS results. By-product formation was shown to out-compete product formation upon fast addition of alkyne, but with dropwise addition of alkyne, product was shown to dominate. A detailed numerical model was developed using PowerSim software to test mechanistic hypotheses. The experimental results were shown to be consistent with the mechanism proposed by Inanaga, and the cycle was elaborated to account for by-product formation. Piers’catalyst, a ruthenium complex with a phosphonium-functionalized carbene ligand, is a fast-initiating living catalyst for a number of olefin metathesis reactions, including ring-opening metathesis polymerization (ROMP) and cross metathesis (CM). Catalyst speciation was monitored in real-time for the ROMP of norbornene and the CM of 1-hexene using PSI-ESI-MS. The expected mass distribution of charged polymer-catalyst species were not observed, but merely catalyst and decomposition species were visible by ESI-MS. NMR and gel permeation chromatography (GPC) were used to determine quantitatively the presence of polymer and the polydispersity index, respectively. The results suggest that while Piers’ catalyst is indeed fast-initiating, the propagation rate greatly outstrips the initiation rate. In a foray into the area of chemical education, a well-known pH-induced colour change exhibited by the anthocyanins in red cabbage was developed into a simple – and ingestible – classroom demonstration. / Graduate / 0485

During the impinging heat transfer, a jet of working fluid, either gas or liquid, will besprayed onto the heat transfer surface. Due to the high turbulence of the fluid, the heat transfer coefficient between the wall and the fluid will be largely enhanced. Previously, an impinging type solar receiver with a cylindrical cavity absorber was designed for solar dish system. However, non-uniform temperature distribution in the circumferential direction was found on absorber surface from the numerical model, which will greatly limit receiver's working temperature and finally affect receiver's efficiency. One of the possible alternatives to solve the problem is through modifying the roughness of the target wall surface. This thesis work aims to evaluate the possibility and is focusing on the study of heat transfer characteristics. The simulation results will be used for future experimental impinging solar receiver optimization work. Computational Fluid Dynamics (CFD) is used to model the conjugate heat transfer phenomenon of atypical air impinging system. The simulation is divided into two parts. The first simulation was conducted with one rib arranged on the target surface where heat transfer coefficient is relatively low to demonstrate the effects of rib shape (triangular,rectangular, and semi-circular) and rib height (2.5mm, 1.5mm, and 0.5mm). The circular rib with 1.5mm height is proved to be most effective among all to acquirerelatively uniform temperature distribution. In the second part, the amount of ribs is taken into consideration in order to reach more uniform surface heat flux. The target wall thickness is also varied to assess its influence.

Time- and rate-dependent materials such as polymers, bituminous materials, and soft materials clearly display all four fundamental responses (i.e. viscoelasticity, viscoplasticity, viscodamage, and healing) where contribution of each response strongly depends on the temperature and loading conditions. This study proposes a new general thermodynamic-based framework to specifically derive thermo-viscoelastic, thermo-viscoplastic, thermo-viscodamage, and micro-damage healing constitutive models for bituminous materials and asphalt mixes. The developed thermodynamic-based framework is general and can be applied for constitutive modeling of different materials such as bituminous materials, soft materials, polymers, and biomaterials. This framework is build on the basis of assuming a form for the Helmohelotz free energy function (i.e. knowing how the material stores energy) and a form for the rate of entropy production (i.e. knowing how the material dissipates energy). However, the focus in this work is placed on constitutive modeling of bituminous materials and asphalt mixes. A viscoplastic softening model is proposed to model the distinct viscoplastic softening response of asphalt mixes subjected to cyclic loading conditions. A systematic procedure for identification of the constitutive model parameters based on optimized experimental effort is proposed. It is shown that this procedure is simple and straightforward and yields unique values for the model material parameters. Subsequently, the proposed model is validated against an extensive experimental data including creep, creep-recovery, repeated creep-recovery, dynamic modulus, constant strain rate, cyclic stress controlled, and cyclic strain controlled tests in both tension and compression and over a wide range of temperatures, stress levels, strain rates, loading/unloading periods, loading frequencies, and confinement levels. It is shown that the model is capable of predicting time-, rate-, and temperature-dependent of asphalt mixes subjected to different loading conditions.

Thesis (Ph. D.)--University of Alabama at Birmingham, 2007. / Title from first page of PDF file (viewed Feb. 6, 2008). Includes bibliographical references.

Thesis (Ph.D.)--University of Tulsa, 1993. / Includes bibliographical references (leaves 254-269).

Thesis (Ph.D.) -- University of Adelaide, Dept. of Paediatrics, 2004. / "March 2004" Includes bibliographical references (leaves 213-272).

Thesis (M. Eng.)(Electronics)--University of Pretoria, 2001. / Title from opening screen (viewed March 10, 2005. Summaries in Afrikaans and English. Includes bibliography and index.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

Thesis (Ph. D.)--Industrial and Systems Engineering, Georgia Institute of Technology, 2006. / Parker, R. Gary, Committee Member ; Shapiro, Alexander, Committee Member ; Nemirovski, Arkadi, Committee Member ; Green, William, Committee Member ; Monteiro, Renato, Committee Chair.

Thesis (Ph.D.)--Baylor University, 2009. / Includes bibliographical references (p. 77-79).