Environmental concerns have brought attention to the requirement for more efficient and renewable processes for chemicals production. Lignin is the second most abundant natural polymer, and might serve as a sustainable resource for manufacturing fuels and aromatic derivatives for the chemicals industry after being depolymerised. In this work, two main approaches were investigated with the aim of treatment of lignin with a mediator, 2,2’-azinobis(3-ethylbenthiazoline-6-sulfonic acid) diammonium salt (ABTS), in 1-ethyl-3-methylimidazolium ethyl sulfate, ([C2mim][C2SO4]). In the first approach, laccase from Trametes versicolor (LTV) was used to treat organosolv lignin, using [C2mim][C2SO4] as a co-solvent in the presence of ABTS. LTV was shown to possess catalytic activity for the degradation of organolsov lignin in systems containing ionic liquid and syringaldehyde was found to be a major product obtained from the process. ABTS alone has been evaluated for its reaction with lignin by means of cyclic voltammetry (CV). Here, the non-phenolic lignin model compound veratryl alcohol and three types of lignin (organosolv, Kraft and lignosulfonate) were specifically examined. The presence of either veratryl alcohol or organosolv lignin increased the second oxidation peak of ABTS under select conditions, indicating the ABTS-mediated oxidation of these molecules at high potentials in [C2mim][C2SO4]. Furthermore, CV was applied as a quick and efficient way to explore the impact of water in the ABTS-mediated oxidation of both organosolv and lignosulfonate lignin. Higher catalytic efficiencies of ABTS were observed for lignosulfonate solutions either in sodium acetate buffer, or when [C2mim][C2SO4] (15% v/v) was present in an aqueous solution, whilst there was no change found in the catalytic efficiency of ABTS in neat [C2mim][C2SO4]-lignosulfonate mixtures relative to ABTS alone. In contrast, organosolv showed an initial increase in oxidation, followed by a significant decrease on increasing the water content of a [C2mim][C2SO4] solution. Despite enhanced lignin solubility in ionic liquids, the yields of small molecules attributed to depolymerisation in ionic liquids are often quite low. Since depolymerisation approaches examined herein are thought to proceed via free-radical mediated mechanisms, two different stable radicals 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ABTS were assessed for the rapid monitoring of radical activity of lignin-related compounds in ionic liquid systems. While these assays are successful in aqueous and organic solvent systems, the presence of the ionic liquids complicates the assay procedure, requiring further developmental work.

Dosators (and other machines operating on generally similar principles) are widely used in the pharmaceutical industry for dosing products that are delivered to the customer in powder form (i.e. capsules and dry inhaled powder applications). However a significant problem for this technology is the ability to predict how accurately and reliably, new formulations can be dosed from these machines prior to scale-up for manufacture. Dosator filling machines have been on the market for over forty years, and their mechanisms have been refined over the time; in parallel with development work of formulation scientists. Despite the work that has progressed in both of these important fields, there has been only a limited improvement in the understanding of how the formulations behave when introduced into production line equipment. Typical problems include variation in potency and manufacturing dose weight – both being issues that can be difficult to predict and counter (especially where mainly the manufacturing process is undertaken on a batch basis). Many manufacturing problems can be traced back to an inadequate understanding of the bulk properties of the powders at the formulation stage. Common issues encountered during full scale production include extended commissioning; high levels of out of specification materials (specifically through dose weight variation). The project aims to provide a predictive tool to industry, the use of which can improve manufacturing efficiency, minimise costs and risk when launching new products. The approach proposed focuses on the development of an analytical model for the pick up and discharge of powder into and out of dosators, based upon established particle/powder characterisation techniques combined with an improved understanding of dosator machine factors, constitutive models and geometry of the machine. The model will be used to predict fill dose weights and filling/discharge behaviour of new products in dosator fillings systems; likewise, to investigate what changes in powder flow properties mean to dosator operation. Recommendations for the practical use of flow property measurement techniques in conjunction with the model are also outputs from this project. To simulate the process and (very importantly) validate the model, a dosator single shot testrig was engineered at The Wolfson Centre to measure forces acting on the dosator during the filling stage, the force required to eject the dose and the dose weight. In addition other important aids, such as a dosator demonstrator and an ultimate bearing application of soil mechanics, are key in the understanding of the process and estimate the stress distribution occurring in the stages of the operation. In addition, the development of this research provides a better understanding of the compaction phenomena in dosator operation, and more importantly, critical flow properties and machine settings factors compromising the uniformity of the fill dose weight in production lines using dosator filling machines not mentioned in the literature yet. Although this project has focussed on dosators, the general concept could be applicable to other volumetric powder filling systems.

The combustion and emissions performance of oxygenated fuels has been investigated in a modern direct-injection spark-ignition (DISI) engine. In particular, the new biofuel candidate, 2,5-dimethylfuran, otherwise known as DMF, has been assessed as a future automotive fuel against ethanol, the most commercially accepted spark-ignition (SI) biofuel. When operating with DMF, the engine performance and emissions are less sensitive to changes in key control parameters than with gasoline. This allows a wider window for improving performance and/or reducing emissions. The relevance of modern injection strategies to increase performance or efficiency has also been assessed when using DMF. The use of split-injection at full load is shown to be less beneficial than with gasoline. Novel fuel preparation techniques have been investigated by comparing externally supplied gasoline-biofuel blends (conventional method) to internally mixed, dual-injection blends. This new mode presents an avenue for optimising oxygenated fuels with a low heat of vaporization, such as DMF and n-butanol; low blends with gasoline (≤25% by volume) are more efficiently utilised than in external blends. Furthermore, the particulate matter (PM) emissions can be reduced with dual-injection because gasoline is supplied through PFI. The unlegislated emissions when using DMF have been benchmarked against gasoline and compared to other oxygenated fuels. In particular, the emissions of the major carbonyls are lower when using DMF compared to gasoline and even less so than ethanol, which heavily emits acetaldehyde and formaldehyde. The dual-injection mode further reduces the total carbonyl emissions when using DMF and ethanol blends compared to direct-injection (DI).

Understanding the influence of the fabrics microstructure on frictional noise was investigated in terms of surface roughness for three multi-fibre apparel fabrics (denim, cotton and silk) and single-fibre polyester model fabrics. Surface roughness (R\(_a\)) correlated strongly with total noise emitted (R\(^2\) = 0.97) and was attributed to the ‘hairy’ nature of multi-fibre fabrics. In terms of specific frequencies emitted within a fabric’s sound spectrum, the microstructure of the model fabrics was strongly correlated (R\(^2\) = 1.00) with the fundamental harmonic predicted, enabling a ‘fingerprint’ theory to be proposed. Friction coefficients, measured using tribology, of apparel and model fabrics were established, and showed that the major impact on friction was R\(_a\) and fibre type. Furthermore, friction was reduced via the lubrication of hydrocolloid fluid gel particulates, by means of reducing the surface roughness by filling in asperities and reducing the hairy nature of the fibres. Consumer perceptions of fabrics and fabric sounds were established with one-to-one interviews, and the influence of sound on sensory perception and liking was established by manipulating real-time fabric sounds, showing that by altering high and low frequencies, and overall noise, a significant difference in sensory attribute 'textured' can be observed.

In investment casting, the removal of wax from the shell is a critical step which may cause shell failure. It would be advantageous to predict the stress development during de-waxing process with computer simulation. The process was simulated with the consideration of two aspects: (i) The thermo-physical data required to model the shell and wax behaviour in the autoclave environment and (ii) A simulation capable of capturing the interaction between shell, wax and the autoclave environment. Data on mechanical properties, thermal properties, permeability, rheology, thermal expansion and density was gathered for wax and shell as appropriate. Flow-3D was used to simulate the de-wax process such that the shell and wax can be simultaneously modelled. It was shown that the Von misses stress exceeded the expected critical failure stress at certain nodes after steam was introduced to the system. Waxes with higher viscosity were predicted to reach the critical stress sooner. The simulation showed that for the selected drainage orifice sizes that was no or little difference in the time taken to reach the critical stress. Wax compressibility which was considered to represent shell permeability was predicted to have a large effect on shell cracking prediction. In general, the statistics of failure in validation test limited the conclusions that could be drawn. Waxes predicted to show differences in cracking and drainage with increasing orifice size did so in the experiment. The simulated drainage times were greater than determined experimentally by around 380s and this requires further investigation.

Two-stage roll milling of chocolate pastes was studied to investigate the relationships between roll speeds and pressing force with mass processing rate, product particle size and roll torque. A three-roll mill was used, operating in two and three-roll mode for each stage, respectively. A strong correlation (R2=0.97) was found between the size of the largest particles and the surface coverage of the discharge roll. No evidence was found of shear rate affecting the size of the largest particles (p=0.13). Negative torque values were measured on the slower rolls under higher forces and/or speed ratios. The minimum specific mechanical energy input (S\(M\(E\(I) was observed to occur for the lowest pressing force that still resulted in satisfactory material transfer. Theoretical models based on the lubrication approximation (LAT), with and without pressure-dependent viscosity, resulted in lower apparent viscosities found at faster roll speeds, higher speed ratios and/or greater forces. The observed tendency for the material to detach from the slow roll suggests that higher shearing action in the slow boundary causes a greater reduction in paste-roll adhesion, provided that material cohesion exceeds adhesion. A comparison with full 2D FEM solutions revealed differences no greater than 0.02% in the pressure and velocity profiles.

Many foods contain large amounts of saturated fatty acids (SaFa), which are considered unhealthy, and their presence in the diet is one of the contributing factors of cardio-vascular disease, obesity and the inherent risk of diabetes. It has become the driver of food producers to manufacture products with as little of these oils as they can. Reformulation work based on Elmlea whipping creams sought to address this issue, by which the ingredients of the principal formulation were taken and ever increasing levels of liquid oil were added, but keeping the total oil concentration at 34%. Many of its’ properties were tested and the optimum formulation was found to be that containing 20% hydrogenated and 14% liquid oil. Further formulation work was associated with another product: ice-cream. Ice-cream distribution, particularly with its transport over the Rocky Mountains in the US, poses a large problem. Taking ice cream across the Mountains involves travelling at altitudes in excess of 2000 metres and this leads to its expansion due to the reduced air pressures. The product can spoil in transit. Further instabilities arise when extruded from a freezer. This instability was studied extensively in this work. It was seen that larger drops in pressure and at a slower rate were more detrimental to the model foam structure than small pressure differences and a fast rate. The fast pressure release seemed to have less of a detrimental effect on the resultant bubble foam microstructure.

Studies were conducted to explore whether high pressure (up to 700 MPa) could be used in combination with elevated temperatures (up to 90°C initial temperature) to produce ambient stable green beans (Phaseolus vulgaris) with improved quality compared with conventionally heat processed samples. Colour changes, texture change and chlorophyll retention were explored at a range of pressures, temperatures and times using a surface response methodology. Texture changes were essentially related to temperature effects; higher temperatures resulted in a greater loss in texture. Significant improvements in texture retention were possible using High Pressure Sterilisation (HPS) but sample colour was negatively affected. Colour parameters were predicted primarily by time and pressure so deterioration in green vegetable quality for a commercially sterile products appears inevitable when using HPS. The use of ohmic heating as a pre-heating method greatly reduced cook values (T\(_{ref}\) = 100°C, z = 39C°) for colour degradation (down to 0.24, 0.12, 0.35 from 3.02, 2.50, 3.70 minutes for ohmically heating and water bath heated samples respectively) which yielded significant benefits in terms of colour retention of raw materials at the start of the HPS cycle; values of a* and b* for ohmically pre-heated samples were close to that of blanched beans.

Highly conductive (3.0 - 5.0 x 10 \(^{-4}\) \( \Omega\) cm) and transparent (80 – 85% ) ITO films were successfully fabricated on glass and polymer substrates (PET, PEN and PC) by pulsed laser deposition at low temperatures (24 – 150 °C). The influence of deposition conditions on the structural and physical properties of ITO-coated glass substrates was studied. The samples were investigated using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), the fourpoint probe and a spectrophotometer. Sol-gel derived ITO films dip-coated on glass substrates were also studied. The optimum film obtained at a firing temperature of 600 °C had a resistivity of 1.8 x 10 \(^{-2}\) \( \Omega\) cm, and optical transmittance of 80%. The electro-mechanical behaviour of ITO/polymer systems was investigated under uniaxial tension and controlled buckling in tension and compression. The resistance changes were monitored in situ. Cracking and buckling delamination failure modes were observed for all samples investigated at critical strains raging from 2.8 to 3.4%, and from 7.0 to 8.0%, respectively. The results showed that the dominant critical failure mode depends on the applied stress conditions. The ITO/PEN samples showed high flexibility; the samples were buckled in tension down to a 2.6 mm radius of curvature before cracks start to occur.

The stability against coalescence of vegetable oil-in-water “food grade” emulsions in the presence of both surfactant and colloidal particles (hydrophilic silica) has been studied and compared to the stability of systems where only the surfactant or the colloidal particles act as the emulsifier. No attempt was made to stop the emulsions from creaming. Two types of surfactants were selected; those that have the ability to stabilise O/W emulsions on their own (O/W surfactants) and those that cannot (W/O surfactants). Tween 60 and Sodium Caseinate were selected as the O/W surfactants, monoolein and lecithin as the W/O surfactants. These mixed emulsifier systems were shown to induce long-term emulsion stability against coalescence, regardless of the surfactant type, via a synergistic “two-part” mechanism in which both the surfactant and colloidal particles components have specific functions. Nonetheless, the emulsion microstructure was proved to depend on the surfactant’s type and concentration: the use of O/W emulsifiers above a certain concentration induced a displacement of particles from the interface, while such a displacement was not observed using W/O emulsifiers. Further measurements of interfacial tension and contact angle showed that the level of adsorption of solid particles at the interface depended on the surfactant type and concentration.