No description available.

No description available.

Gas-expanded liquids (GXLs) are a new and benign class of pressure-tunable liquid solvents which show tremendous promise as the next sustainable processing medium. In order to realize the potential of GXLs fully, it is necessary to elucidate their cybotactic region and gain an understanding of where properties are different in the bulk and micro-scales and how local structure and order affect both reactions and separations. This work explores the cybotactic region of GXLs and probes the existence and implications of those differences. This study is started by exploring the cybotactic region of ambient liquid mixtures. Thermodynamic models based on intermolecular forces are used to predict the solubility of multi-functional solids in a variety of solvent mixtures. While this part does not lend any insight into GXLs directly, it acts as a stepping stone in both understanding the intermolecular forces that govern the cybotactic region and by opening the gateway to studying solid solubility in GXLs. The rest of the study focuses on the differences between bulk and local properties of GXLs. Different probes of polarity in the cybotactic region are compared and the solute dependence of the local structure is explored. Bulk transport properties are measured with different probes in an effort to see if molecular interactions play a role in governing diffusion processes in GXLs.

No description available.

Thesis (M.S.)--Wisconsin. / Includes bibliographical references (leaves 60-62).

<p>NR 20140804</p>

Fracture mechanics is applied to study the behavior of concrete containing expanded polystyrene (EPS) aggregate replacement. The EPS replaces a portion of the normal weight fine aggregate. Previous research has shown EPS aggregate replacement changes the failure mode in compression from a typical instantaneous failure, as in normal weight concrete (NWC), to a more gradual dissipation of load carrying capacity. This behavior is investigated through the use of fracture mechanics. The fracture energy, critical stress intensity factor and characteristic length of EPS concrete, NWC and fiber reinforced concrete (FRC) are experimentally determined. The two types of tests used to study these properties are the three point bending test recommended by the RILEM technical committee and a wedge splitting test developed recently. The conclusions derived from this research demonstrate that EPS aggregate replacement increases the size of the fracture process zone in front of the crack tip. This increase in size changes the failure mode of concrete allowing it to maintain load after reaching peak load and absorb more energy during the fracture process.

Sustainable technologies are vital to reducing the environmental impact of chemical enterprises. Solvents are often seen as just a medium in which a reaction takes place; however they can also play a dominant role in the overall toxicity of a typical pharmaceutical/fine chemicals batch chemical operation. Further, careful solvent selection for a reaction may also lead to more facile separation and purification of products, thus reducing the overall cost of a chemical process. This thesis presents an environmentally benign processing technique for sustainable biocatalytic reactions coupled with facile built-in separation. An organic aqueous tunable solvent (OATS) system allows access to a hydrophobic substrate which is transformed with a homogeneous enzymatic catalyst in a single liquid phase. Subsequent CO2 addition produces a biphasic mixture where the hydrophobic product partitions preferentially into the organic rich phase for separation while the hydrophilic enzyme catalyst partitions into the aqueous rich phase, where it is recyclable. Processing parameters in OATS systems are discussed and an overall product recovery of 80% is observed after six reaction cycles. Additionally, greater than 99% enantiomeric excess (ee) is shown for catalyzed hydrolysis of rac-1-phenylethyl acetate with Candida antarctica lipase B (CAL B) both before and after CO2-induced separation.

Anion Binding has recently emerged as an important field of study due to the role these small inorganic species play in a plethora of biological processes. Chapter 1 of this thesis describes the biological relevance and scientific justifications for studying the ability of synthetic molecules to transport or extract anions under interfacial conditions. This chapter also serves to underscore the need to study both the thermodynamics and kinetics of anion binding as achieved using synthetic receptors. Methods for determining the thermodynamics of ion recognition are well-developed, and many equilibrium analyses of supramolecular binding events have been reported; however, the kinetics of such interactions are often neglected. Chapter 2 details the author's efforts to address this deficiency with respect to anion-binding and reports progress towards quantitative kinetic analyses of the interaction between cyclo[8]pyrrole (C8), an expanded porphyrin, and two test anions. It has been determined that stopped-flow analysis can provide on and off-rates, as well as activation parameters not accessible through thermodynamic means. Initial flash photolysis kinetic studies have also revealed that C8 has the potential to act as a photosensitizing agent through electron donation. This work is presented in Chapter 3, wherein the author discusses the construction of novel donor-acceptor dyads based on C8. As detailed in this chapter, time-resolved optical analyses have confirmed that photoinduced electron transfer occurs under conditions of photoexcitation and that the lifetime of the charge separated state is approximately 300 [mu]s. Finally, Chapter 4 describes a comprehensive set of spectroscopic work conducted by the author involving porphyrin and porphycenes that have a RuCp* (Cp*: pentamethylcyclopentadienyl) fragment either coordinated to the central porphyrinic core or directly attached to the "[pi]-face" of the macrocycle. These systems display unique intramolecular electron transfer properties that are ascribed to the metallated-porphyrin core acting as an electron acceptor, as opposed to a donor as is normally observed with porphyrins. / text

The traditional method of repairing damaged roads in Atlantic Canada has been to place a hot mix asphalt overlay over the existing road. Though this method provides a new, smooth wearing surface to drive on, it is merely a short term fix. With time, the cracks in the original pavement will reflect to the surface of the new pavement, resulting in failure of the overlay. An alternative option gaining more prominence is the use of a Full Depth Reclamation (FDR) technique, which involves pulverizing the flexible pavement, along with a portion of the underlying layer. This material is then stabilized and recompacted to produce a new base layer that is free of damage. Though FDR has been used for a number of years, there are still problems with variability in the strength of the materials in some projects. It is hypothesized that some of these problems are due to variability and poor quality in the reclaimed materials. It is believed that current pulverization methods contribute to the variability being observed in these materials. Two FDR projects employing different pulverization control methods were studied to examine how the consistency of the reclaimed materials can be improved through the use of a Ground Penetrating Radar (GPR) survey to map the variability in the depth of the pavement. Controlling the thickness ratio of asphalt concrete to granular base materials being pulverized was shown to improve the consistency of materials, properties, and performance. The second phase of this research project studied how improving the gradation of the reclaimed materials with the addition of a crusher dust might result in improved performance of stabilized base materials, in this case stabilized with expanded asphalt. The effect of construction variability on the improved materials was also studied by varying both the moisture content, and asphalt content from optimum conditions, as might be expected during construction. Results indicated that the quality of the stabilized FDR materials can be significantly improved by bringing the material gradation closer to the theoretical maximum density gradation. The performance of the stabilized materials can be affected by both the mixing moisture content, and the asphalt content used during stabilization. This suggests that effective quality control, and stricter specifications on the constructed product would result in more reliable, effective FDR pavements. / A study on the control of the consistency of pulverized FDR materials, as well as a study examining how to improve the performance of these pulverized materials.