The application of High Throughput Experimentation (HTE) stirred vessels in the catalyst and pharmaceutical industries enable the parallel screening of potential formulations. Such tasks only require a fraction of the raw material and experimental time that are needed in conventional lab scale reactors. However their small sizes (~ 15-250 ml) contribute to a low Reynolds Number, Re, which results in poor mixing efficiencies. Together with unconventional geometries, i.e. lack of baffles and simple impeller designs, their fundamentals are not fully understood. The present study applies Particle Image Velocimetry (2-D PIV) and Planar Laser Induced Fluorescence (PLIF) techniques to a HTE scale stirred vessel (T = 45 mm, V = 72 ml) to determine the mixing behaviour. Three mixing strategies: centreline unbaffled (U), conventional baffled (B) and off-centre eccentric agitator (E) configurations, were investigated using a pitched blade turbine (PBT). Experiments were performed in the high transitional regime (Re \( \approx\) 6000) using distilled water as the working fluid. A uniform power input of P/V = 168Wm\(^{-3}\) was applied. A method based on multiple horizontal and vertical 2-D PIV measurements was used to reconstruct the 3-D flow field in each of these configurations, since the conventional 3-D PIV is unusable at this scale. It was found that the determination of turbulent kinetic energy (TKE) using the isotropic assumption was perfectly valid for (B), but will lead to a considerable underestimation in both (U) and (E). In addition to the three configurations, a square section vessel (S) (T = 41.5 mm, V = 72 ml) and regular vessel with a tilted impeller axis (T) were also studied. With a modified experimental procedure a log variance method for mixing time was applied using PLIF where all the usable pixels in an image were accounted for. Not only was (U) found to be highly inefficient, (B) also registered a slower mixing time due to a small amount of tracer being trapped behind the baffles, which makes the (E), (S) and (T) an even better choice in turbulent mixing. The use of (S) enabled the formation of a more compact HTE unit, also its trailing vortices were able to reach a height of y/H = 0.6, bringing more energy to the upper reaches of vessel, as visualised by angle resolved PIV measurements. The flow number of impeller and the amount of pseudo-turbulence were also determined and they agreed well with literature values. However in the laminar mixing regime using Polypropylene Glycol (PPG) as the Newtonian working fluid (μ = 0.4–0.8 Pa s, P/V = 0.6–5.5 kWm\(^{-3}\), Re = 5–35), at low Re values, (S) only managed a mixing performance comparable to the (U) configuration as the baffling effect of its four corners are less pronounced. However, mixing performance improves in (S) at higher Re values. (B) and (E) gave a comparable mixing performance, suggesting (E) should always be adopted for its viability in both turbulent and laminar mixing regimes. For gas-liquid mixing using air and water (P\(_G\)/V = 168 Wm\(^{-3}\), Q\(_G\) = 0.5–1.0 vvm), an image analysis algorithm was developed which enabled measurement of gas and liquid phase velocities separately. In addition to the PBT, a Rushton Disk Turbine (RDT) was also used (C = D = 0.33T). The power input required for the small mixing vessel to achieve complete gas dispersion was not achievable at the required gas flow rate; hence the experiments are carried out in the flooding regime. This had the advantage of clearly discernible differences between gas and liquid flow pattern for validation purposes. A new image algorithm was written to separate out bubbles in the imaging plane which transforms the in-plane bubbles into tracer particles. The local velocities of the gas phase are then obtained using the conventional cross-correlation technique. The results showed qualitative agreement with experimental observations of global gas phase flow patterns in literature.

This aim of this work is to determine carbon formation when methane is reformed directly inside the SOFC anodes, from thermodynamic equilibrium and kinetic approaches. Two carbon formation determination approaches - carbon-steam equilibrium and carbon activity approaches were then presented, compared and discussed. The consideration of the reversed syngas formation reaction is important to the carbon activity approach, which is expected to be a useful tool for determining carbon formation in the anode recirculation system. The investigation of the combined steam and dry methane reforming, both thermodynamic equilibrium computational modelling approach and kinetic experimental validation were presented in this work. Different ratios among methane, steam and carbon dioxide, leading to different oxygen to carbon atomic were used to examine the methane reforming and the carbon formation prevention abilities. Finally, a kinetic modelling for a methane fed SOFC with anode recirculation system was built based on the integration of different functions for a more detailed investigation. The combination of different fuel current densities (i.e.0.5, 1.0 and 1.4), steam to methane ratios (i.e. 0.25-4.0) in the fuel and different recycling rate (i.e.10%-90%) were given to the model to investigate the effects of fuel conditions on the system operation.

The sensing of biological compounds is of vital importance to the screening and diagnosis of disease. The importance of such assays is due to the correlation observed between the observed levels of biological compounds and diseases such as cancer and diabetes mellitus. Compounds such as sugars and proteins are included in this useful class of molecules which can be used to detect pathology. Currently the detection of these compounds is achieved through the use of other biologically derived molecules- typically antibodies and enzymes. However, sensors based on these compounds can be limited in terms of their stability and suitability. Therefore there is a constant drive for novel detection methods for such molecules. In this context, the aims of the work described herein, are to produce synthetic sensing systems for the selective detection of saccharides and glycoproteins. This work will use principles of nanotechnology and self-assembly to produce surface sensors which exploit the revisable interactions of boronic acids to bind compounds of interest, and which employ surface plasmon resonance spectroscopy to enable the label free reporting of these binding events.

Suspensions of micron sized air cells, Air Filled Emulsions (AFEs), represent a new colloidal material with outstanding physical properties. They have the potential for technological applications in very different fields such as biomedical, environmental sciences and the food industry. This thesis focuses on the construction of AFEs and their use as ingredients to construct reduced fat and calorie emulsion-based products. These microstructurally complex materials have been termed triphasic A/O/W emulsions. A sonochemical templating process has allowed for the construction of air cells (the majority around 0.5-10 μm) in the size range of oil droplets found in emulsion based foods. Air cells were stabilised with either hydrophobins, obtained from submerged fermentation and extraction, or other cysteine rich but more common proteins such as bovine serum albumin (BSA) and egg albumen (EWP). The air cells were stable against disproportionation and ripening for substantial periods of time. They resisted destabilisation effect of oil droplets and could survive unit operations involving mild vacuum treatment and centrifugal forces, relatively high shear forces, temperatures and pressures. Triphasic A/O/W emulsions were created with up to 60% included phase of air and oil in an aqueous continuous phase. This gave a greater than 50% reduction in lipid content. Comparative rheology and tribology showed that the triphasic A/O/W emulsions could have similar if not better lubrication properties than a full O/W version. The molecular properties of the protein used for the AFEs played a crucial role in the determination of lubrication properties (mouth-feel). Moreover, AFEs and triphasic emulsions offer the potential for new structures and textures for the food industry due to their self interaction to give a weak gel

Off-target contamination (or spray drift) during agricultural chemical application, arising from removal of small (diameter < 100 m) droplets from sprays by atmospheric or vehicle-generated cross flows, is investigated experimentally. The primary requirement for realistic wind tunnel studies is identified from background review as matching the full-scale logarithmic man velocity profile with suitable surface roughness parameters. A general calculation scheme is presented for spacing horizontal flat plates to simulate weakly-sheared mean velocity profiles. Adequate full-scale matching of logarithmic mean velocity profiles is achieved after systematic equipment modification. Comparative field and wind tunnel experiments using single nozzles show adequate agreement following the above approach, indicating that air entrained into the liquid spray stabilizes the spray to the cross flow action. Measurements within an agricultural spray in still air show that small droplets are passively transported within the entrained air field, whose characteristic turbulence length scale is too small to contribute to droplet dispersion. Wind tunnel studies employing conventional sprays show small droplet removal associated with regions where the entrained air velocity is less than the cross flow velocity, with essentially passive downwind transport. Numerical simulations of spray drift must clearly incorporate characteristics of the entrained air velocity field.

Bacteria are used to ‘grow’ and scaffold precious metal nanoparticles possessing certain catalytic activities. Focusing on Escherichia coli, this thesis aims to investigate the catalytic behaviours of E. coli-supported palladium (bio-Pd/E. coli) or bimetallic gold-palladium (bio- AuPd/E. coli) in hydrogenations and oxidations operated in laboratory-scale three-phase slurry reactors. A discussion of hydrodynamics, mass transfer, reaction mechanisms and corresponding reaction performance is systematically presented for two major industrially important reactions: soybean oil hydrogenation and benzyl alcohol oxidation. Thermogravimetric analysis indicated a suitable operating temperature of below 175\(^0\)C for the E. coli-supported catalyst. A loading of 5 wt%Pd on E. coli showed an average particle size of 4.31 nm estimated by TEM measurements and a crystallite size of 4.12 nm using Scherrer’s equation from obtained X-ray powder diffraction data. This was smaller than an active particle diameter of 12.77 nm for 5wt%Pd/Al\(_2\)O\(_3\) (determined by CO chemisorption). It is concluded that biomass-supported precious metal catalyst is an environmentally attractive alternative to conventional heterogeneous catalyst for application in industrial catalytic processes.

Aggregation of asphaltenes has attracted interest due to the impact on the crude-oil industry. Despite extensive studies on the molecular-structure of natural asphaltene, fundamental knowledge of their aggregation is incomplete. It is unclear how the driving forces of association are related to the molecular architecture and the solvent species, which ultimately affect the aggregation mechanism. In this dissertation, dynamic-light-scattering (DLS) experiments and molecular-dynamics (MD) simulations were performed to investigate the relation between asphaltene chemical-structure and solvent species. The model compounds studied isolate the driving forces of aggregation by varying the peripheral chain-length and functional-groups (triphenylene-cored models) in organic solvents. The results isolate the structure-function relationships. Increasing the chain length imposes restriction upon the nanoaggregate formation, while non-centrosymmetric models appear to be more prone to aggregation. Furthermore, polar components in asphaltene molecular-architecture are observed to increase aggregation potential, more than π-stacking. Hexabenzocoronene-cored models exhibit a structurally selective aggregation mechanisms, as the planar molecules are more liable to aggregate and precipitate than the non-planar models due to π-stacking hindrance. The motivation behind the development and testing of model polyaromatic compounds lies in the pursuit of isolating the source structural-dependence of the compounds interactions. This is done by assessing the solute-solute and solute-solvent associations by experimental and computational approaches, to underpin the structure-to-function relation dictated by aromatic and/or polar molecules in aromatic or aliphatic solvents. This dissertation provides insight for the aggregation of model compounds of varying molecular architectures, and sheds light on the intermolecular interactions affected by these variations and the solvent species.

The modelling of two key areas of transport phenomena in a new polymetallic smelter has been achieved by using both mathematical andphysical models to investigate optimum operating conditions. A study of oxygen mass transfer caused by multiple top-blown, subsonic gas jets contacting water flowing in a full-scale channel model of the smelter converting hearth has been carried out. A liquid phase solute mass transfer model that incorporates a flowing liquid phase has been developed. It has been used to compare mass transfer for both open-packed and close-packed multiple lance arrays of 2.26 mm, 4.95 mm, 10.95 mm and 24.40 mm nozzles delivering the same quantity of gas. It was found that for fewer lances of the larger nozzle diameters, up to a 75% reduction in liquid phase mass transfer occurred especially for the close-packed configurations. This restriction of mass transfer will result in reduced metal losses in the analogous smelter situation. Over a wide range of channel flowrates the mass transfer coefficient was found to be independent of water velocity. A computer model that predicts the amount of fog formation in the zinc vacuum condenser of the smelter for binary vapour/gas mixtures has identified operating conditions most susceptible to vapour fogging and subsequent metal losses. A fog problem is most likely to occur in condensable mixtures with high vapour concentrations and low initial quantities of superheat, and at low cooling wall temperatures as well as at high total pressures. Any lead in a Pb/Zn/N\({_2}\) condensable mixture will fog heterogeneously at least 400°C before zinc droplets form and act as condensation nuclei for the zinc vapour. An engineering approach to estimating quantities of homogeneous fog formation has been developed and is used to analyse the performance of the Imperial Smelting Furnace zinc condenser and the Port Pirie Vacuum Dezincing Unit.

Nanostructured MoS\(_2\) and ZnFe\(_2\)O\(_4\) were synthesised and tested as catalytic water splitting photoelectrodes. MoS\(_2\) was nanopatterned from a bulk crystal using a combination of nanosphere lithography and plasma etching. Three morphologies were produced: nanospheres deposited with interstices between them produced nanopillars, nanospheres squashed into hexagons imprinted a nanowell pattern, and linked nanopillars resulted from parts of each. The MoS\(_2\) was tested as a photocathode and morphologies with linkages between features had improved catalysis than those without. This was attributed to the layered structure of MoS\(_2\). These samples degraded in air to MoSxO(\(_2\)\(_-\)\(_x\)), and an electrochemical technique utilising Na\(_2\)S\(_2\)O\(_3\) was used to re-sulfidate the MoSxO(\(_2\)\(_-\)\(_x\)). The technique decreased the onset potential from -0.27 V SHE to -0.17 V SHE, and the Tafel slope from 282 mV dec\(^{-1}\) to 87 mV dec\(^{-1}\). ZnFe\(_2\)O\(_4\) electrodes were deposited by AACVD from a precursor molecule. The deposition solvent composition was systematically altered between methanol and ethanol to examine its effect on the nanostructure. ZnFe\(_2\)O\(_4\) electrodes deposited from predominantely methanol solvent had compact morphologies due to heterogenous nucleation, while the electrodes deposited from predominantly ethanol solvent had high surface area structures due to homogeneous nucleation. The more exothermic enthalpy of combustion of ethanol was deemed responsible.

Hydrocolloid materials have been used for some time in the fields of regenerative medicine and drug delivery. Despite a significant body of work, to date the majority of research in the area has focused on relatively simple compositions and microstructures. In comparison, the food industry has long used refined and often subtle methods to structure and thereby tailor the release and handling properties of a vast range of similar materials. In this thesis, a range of processing methodologies has been used to generate novel materials intended for use in the regenerative medicine and drug delivery using gellan and kappa carrageenan. The thesis demonstrates how even small changes in process conditions can result in significant changes in the way a material handles and may deliver therapeutic molecules. This thesis has demonstrated that gellan can be used to form robust quiescent structures, as well as shear thinning fluid materials by changing the processing and formulation. Furthermore, it was demonstrated that it was possible to generate a novel cell delivery device by the hydration of kappa carrageenan in warm biomedical buffers. Overall this thesis demonstrates the range and complexity of structures that can be produced using the relatively small number of polymers.