Chapter One reviews the synthesis, properties and reactions of 2-methyleneaziridines, the subject of this thesis. Chapter Two describes the use of these heterocycles in the development of a new four-component synthesis of biologically important α-aminophosphonates. This new chemistry proceeds in moderate to good yield via a “one-pot” process that involves the sequential formation of three new intermolecular bonds and a quaternary carbon centre. This reaction is tolerant to a range of functionalities incorporated in the various components. Deprotection of one of these α-aminophosphonates to the corresponding α-aminophosphonic acid is achieved via a two-step process in very good yield. Chapter Three discusses efforts made towards the development of a multi-component imino Diels-Alder reaction for the generation of 2,3-dihydro-4-pyridones. Initial work suggests acyclic ketimine intermediates are unsuitable for this process. Chapter Four reports unsuccessful attempts made to generate methyleneaziridines bearing electron-withdrawing substituents via in situ N-derivatisation. In Chapter Five, the synthesis of 1,1-disubstituted tetrahydro-β-carbolines from methyleneaziridines is described. The reaction is shown to proceed in moderate to very good yields and a range of β-carbolines were successfully synthesised. High levels of diastereocontrol are demonstrated using a substrate containing a pre-existing stereocentre. Chapter Six details the experimental procedures and characterisation data for the novel compounds produced.

Thermal treatment is the most common method used by industry to ensure food is safe for consumption and to increase its storage life. To ensure safety, food is often overprocessed which can significantly affect its nutritional value as well as taste and flavour attributes. In this study, the heating and mixing efficiency of a bespoke vessel used for heat treatment of complex foodstuffs (250 litre ‘Vesuvio’ vessel manufactured by Giusti Ltd) was investigated. Enzymatic Time Temperature Integrators (TTIs) were used to determine the heat treatment efficiency. TTIs are small unattached measurement devices which contain a thermally labile enzyme: determination of the degree of degradation of the enzyme at the end of the thermal process enables the integrated temperature history to be obtained. TTIs can be used for process validation, particularly when the processing environment is inaccessible for fixed devices such as thermocouples. The reliability and accuracy of the TTIs was determined by exposure to various non isothermal industrially relevant temperature profiles using a Peltier stage and Polymerase Chain Reaction (PCR) device. The integrated temperature histories obtained by the TTIs’ correlated generally well with data obtained from thermocouples installed in parallel, although the error increases with holding time of the heat treatment. The work showed that the TTIs can be used reliably over a range (e.g. Enzymatic TTI made from the α-amylase from the Bacillus Licheniformis can reliably used from 5 to 30 minutes at 85°C) which is relevant for conditions of thermal pasteurisation of interest to this study. The range of time temperature profiles that enzymatic TTIs can monitor depends on the thermal resistance of the enzyme. The heat treatment efficacy of the ‘Vesuvio’ vessel was evaluated using TTIs and two thermocouples fixed onto the vessel wall and impeller shaft at the centre of the vessel. In addition to the plain or ‘free’ TTIs, a new TTI was developed where it was placed at the centre of an open structure to prevent intimate contact between the surface of the TTI and the vessel wall (‘Golf Ball’ and ‘Tie Clip’ TTIs). The food fluid could, however, penetrate the structure. The parameters examined in the study were fluid rheology, fill level (100% and 120% filling level) and the heating options (steam heating via wall jacket or direct injection). The study showed that the thermal process efficiency is lowered as the fluid viscosity increases when the wall jacket was used alone; this was observed by greater differences between the temperatures recorded by the thermocouples between the centre and the vessel wall. This was overcome by using direct steam injection into the vessel contents. Overfilling the vessel was also found to affect performance. The ‘free’ TTIs were found to have a higher thermal treatment than the TTIs which could not directly contact the wall. Under perfect mixing conditions, the ‘free’ TTIs and the TTIs placed inside the open structure should both give close results. However, this is not the case and it can be seen that the discrepancy increases when the mixing conditions worsen (increase of the fluid viscosity, no use of steam injection). The reliability of the TTIs as a validation tool is dependent upon their following the same path as the food fluid, i.e. they should be isokinetic and follow the fluid streamlines. To investigate this issue, the flow of both fluid and TTIs was examined on a reduced scale version of the ‘Vesuvio’ vessel using Particle Image Velocimetry (PIV) and Positron Emission Particle Tracking (PEPT). The effect of changing fluid rheology, agitation speed and filling level were investigated on the basis of a scaling at constant power per unit mass. The PIV experiments showed that the flow was laminar/transitional through bulk of vessel, with significant flow instabilities at the free surface and at the trailing edge of the impeller. Bulk mixing can therefore be expected to occur by laminar mechanisms with some mixing by eddy diffusion present at the free surface. The mixing pattern was not affected by rheology or agitation speed, however, overfilling of the vessel appeared to move the centre of the fluid rotation to above the impeller shaft, as verified using PEPT. PEPT was also applied by inserting either the free tracer into the fluid or placing it within a TTI. Significant differences in the path taken by the TTI and the fluid were observed when the TTI had a significant settling velocity in the fluid. Hence TTIs cannot be assumed to give reliable results in low viscosity fluids (e.g. water).

There is a growing interest to incorporate melamine formaldehyde (MF) microcapsules containing perfume oil in detergents, which can be delivered to consumers at end-use applications. The microcapsules should have desirable properties including optimum mechanical strength and capability to adhere on fabric surfaces after laundry. They should be strong enough to withstand a serious of engineering processes including pumping, mixing, drying etc, but be weak enough to be ruptured by consumers in post-laundry handling. For this purpose, the mechanical strength of MF microcapsules made by different processing conditions, with additional coating, after being dried using different methods and being exposed to various suspending liquids were characterised in this work. Moreover, the adhesion of single MF microcapsules or single MF microspheres on flat fabric films in air or in liquids with different concentrations of detergent, surfactants, pH etc was investigated. The mechanical strength of MF microcapsules produced using an in-situ polymerisation technique were characterised by a micromanipulation technique. Conventionally, the mechanical strength parameters include microcapsule diameter, rupture force, deformation at rupture and nominal rupture stress (the ratio of the rupture force to the initial cross-sectional area of individual microcapsule). It was found that larger microcapsules in a sample on average had greater rupture force but small ones had higher nominal rupture stress. Since the rupture force or nominal rupture stress depends on the size of microcapsules, which is not easy to use particularly for comparison of the mechanical strength of microcapsules in different samples, a new strength parameter nominal wall tension at rupture has been proposed in this work, which is defined as the ratio of the rupture force to the circumference of individual microcapsule. The results from micromanipulation measurements showed that the increase of core/capsule ratio in weight percentage reduced the nominal wall tension of microcapsules. The use of silicate coating on surface of MF microcapsules increased the nominal wall tension of microcapsules and made microcapsules more brittle. The nominal wall tension of microcapsules did not differ significantly when the pH of their suspending liquid ranged from 2 to 11 for a duration of 25 hours. It has also been shown that the prolonged polymerisation time alone or combined with the elevated polymerisation temperature increased the nominal wall tension of MF microcapsules. Furthermore, there was no significant change in the nominal wall tension of microcapsules after being oven dried, fluidised bed dried or freeze dried. However, there was a significant increase in the nominal rupture tension of microcapsules after being spray dried, which resulted from destroying weak (in general large) microcapsules in the drying process. Modelling of the force versus displacement data from micromanipulation has been attempted in order to determine intrinsic mechanical property parameters, such as Young’s modulus, yield stress and stress at rupture that requires to know the contact area between a compressed microcapsule and force probe at rupture. The mean Young’s modulus of MF microcapsules Ec predicted from the Hertz model was found to be 32±4 MPa which represents the modulus of single whole microcapsule. In addition, the Young’s modulus of MF microcapsule wall material Ew was found to be 8±1 GPa by applying finite element analysis with a linear elastic model. A correlation describing the relationship between E\(_c\) and E\(_w\) has been developed based on the modelled results, wall thickness and diameter of microcapsules. The Hertz model and Johnson’s plastic model were further applied to determine the rupture stress of single MF microcapsules, which take their rupture deformation into consideration. The models help to determine the mechanical strength of microcapsules precisely. Real fabric surface can be very rough, and quantification of the adhesion of single microcapsules on such rough surface can be difficult so that flat fabric surface was fabricated. Cotton films were successfully generated by dissolving cotton powder and their properties were also characterised including their surface roughness, thickness, contact angle and purity. The adhesive forces between MF microcapsules/MF microparticles and cotton films under ambient condition at air RH above 40% were measured using an AFM technique, which was considered to be dominated by capillary forces. It was also found that there was little adhesion between MF microparticle and cotton films in detergent or surfactant solution. Instead, repulsion between them was observed and reduced with the increase of detergent/surfactant concentration and the decrease in solution pH. It was suggested that the repulsion was contributed from two mechanisms of steric interaction and electrostatic repulsion. It is believed that this work can be used to guide formulation and processing of MF microcapsules with desirable mechanical strength. The studies on the adhesion between MF microcapsules/microparticles and cotton films under ambient condition or in the detergent solutions should be beneficial to the future work to enhance adhesion of microcapsules on fabric surface via modification of the surface compositions and morphology of microcapsules.

This thesis investigates the structural and physical effects of changing the ratio of Mn:Ga in the anion deficient perovskite, YSr\(_3\)Mn\(_{4-x}\)GaxO\(_{10.5}\). YSr\(_3\)Mn\(_{4-x}\)GaxO\(_{10.5}\) crystallises in the tetragonal space group I4/mmm, with lattice parameters a~7.64 Å and c~15.66 Å. Magnetic characterisation indicates that the material is antiferromagnetic overall, with ferromagnetic ordering in the [001] direction of the unit cell. Earlier work on the structural analogue, Y\(_{1.07}\)Sr\(_{2.93}\)Mn\(_{2.67}\)Ga\(_{1.33}\)O\(_{10.5}\), identified a magnetic peak in the neutron diffraction pattern that could not be fitted following refinement of NPD data. This work concluded that the extra peak was due to a small MnO impurity. The effects of oxidation and fluorination on the structural and physical properties of YSr\(_3\)Mn\(_{4-x}\)Ga\(_x\)O\(_{10.5}\) with various Mn:Ga ratios are investigated. The physical and structural effects of substituting Mn\(^{3+}\) or Co\(^{3+}\) for Fe\(^{3+}\) in the perovskite related material, Pb\(_4\)Fe\(_3\)O\(_8\)Cl, have been investigated using XRPD, NPD and magnetic susceptibility measurements. An earlier characterisation of Pb\(_8\)WO\(_{10}\)Cl\(_2\) suggested a deficit on all atom sites within the unit cell. This work suggests a different structure with an intact cation and main oxygen sub-lattice. The site of an additional oxygen was established linked to tungsten. Pb\(_8\)WO\(_{10}\)Cl\(_2\) crystallises in space group I4/mmm, with a = 3.9846(2) and c = 22.690(2) Å.

The aim of this study was to create a bi-layered packed bed chromatography support for the purification of nano-sized bioproducts. The effect of three different chemistry approaches, different solvent conditions, and microwave heating were investigated on construction of a bi-layered support. Sepharose CL-6B was activated with allyl glycidyl ether (routes 1&2). The inert outer layer was created in route 1 by reacting bromine with the allyl groups at the surface, followed by the addition of sodium hydroxide. Creation of the outer layer in route 2 was achieved by oxidation of surface groups with potassium permanganate. In both synthesises the allyl groups remaining were reacted with bromine and a charged amine ligand was coupled to the inner core. The activation step of route 3 resulted in the introduction of three membered epoxide groups throughout the support. Surface groups were reacted with sodium hydroxide or hydrochloric acid. Finally a charged amine ligand was coupled to the support by reacting trimethylamine hydrochloride with the remaining epoxide groups. Supports created by route 1 eliminated 91% of plasmid DNA binding whilst maintaining a high protein binding capacity. This was achieved by using DMS0 as the solvent in the bromination step and employing microwave heating. Route 2 proved to be the least successful in creating a bi-layered support. The beads created under hydrochloric acid-methanol conditions (route 3) reduced 91% of the plasmid DNA binding whilst maintaining a high protein binding capacity. This study revealed that microwave heating was a useful tool in the synthesis of chromatography supports. Subsequently, a comprehensive study was untaken investigating the effects of microwaves on numerous chromatography matrices.

Considerable progress in understanding and predicting two-phase flow phenomena has been advanced over the past 10 years or so using a combination of model development, computational techniques and well-designed experiments. However, there remain many modelling uncertainties mainly associated with inadequate physical prescriptions rather than with limitations of the numerical schemes. The present project addresses some of these questions, in particular in relation to dispersive transport by transient large eddies in free shear flows.

The work in this thesis used an in vitro flow system, which incorporated a capillary viscometer, to systematically determine the effects that haemodynamic variables, or rheological properties of the perfused, fluorescently-labelled blood, had on the behaviour of leukocytes and platelets. By varying shear rate and stress, blood haematocrit, and aggregation and deformability of red cells, we obtained evidence that leukocyte adhesion was dictated by the number of free-flowing cells 'marginated' near the vessel wall and the force experienced by their initial adhesive bonds. Platelet adhesion was dependent on the velocity of the free-flowing cells near the vessel wall and the force experienced by the platelets once adhered. In contrast to leukocytes, variation in platelet adhesion appeared less dependent on variation in the number of free-flowing cells near the vessel wall, but dictated more by the width of the peripheral plasma layer; a thinner plasma layer promoting more efficient platelet adhesion. Overall, this thesis provides evidence that the differential margination and adhesion of leukocytes and platelets is largely a result of the difference in their size. Thus, it seems that the sizes of RBC, leukocytes and platelets are all adapted to provide efficient immune and haemostatic responses in different regions of the circulation.

The optimisations of reduction and operation of Ni-YSZ anode supported micro tubular cells on pure methane were studied. A major problem of SOFCs is nickel anode performance on methane and higher hydrocarbons. The aim of this work was to study the effect of reduction and operation of anode-supported microtubular SOFCs using methane as both reductant and fuel. The results were compared to those from optimised operation using hydrogen. To measure mechanical strength, the three point bending test was employed. Temperature programmed oxidation (TPO) results were investigated to measure the carbon deposition on the anode in order to assess potential damage to the cermet catalyst. Also field emission scanning electron microscope (FE-SEM) and Energy-Dispersive X-ray spectroscopy EDS results were analysed on the anode surface.

The primary objective was the preparation of a complete mass balance around an aerobic treatment system for pig slurry, to quantify the various forms of nitrogen entering and leaving under different conditions. The purpose of this was to assess the effect of such treatment conditions in terms of the amount of polluting forms of nitrogen generated from the slurry. A laboratory scale reactor (designed for this study) was operated under three separate residence times of 2, 4, and 8 days, and aeration level indicated by a redox value in the range of E\(_{Ag/AgCl}\) = +100 to +200 mV; the latter two giving nitrifying conditions. Emissions of di-nitrogen gas are a major component of a nitrogen mass balance, yet one which has been often neglected because of difficulties in distinguishing it from that in the atmosphere. A novel technique was developed in which atmospheric N\(_2\) in the reactor headspace was removed by flushing the system with an 80/20 gas mixture of argon/oxygen. This left microbially derived N\(_2\) available for collection and analysis by mass spectrometry. Established methods were applied for the measurement of other gaseous nitrogen emissions (NH\(_3\), N\(_2\)O, NO) and other forms of nitrogen in the slurry (organic-N, NH\(_4^+\), NO\(_2^-\) and NO\(_3^-\)). The steam distillation technique for nitrite and nitrate was found to be unreliable, therefore, high performance liquid chromatography was used as an alternative. The existence of the intermediate nitrified N form of hydroxylamine is postulated but was not quantified in this study. The presence of unidentified components in raw slurry was investigated using HPLC, but only chloride and acetate could be recognised with a high degree of confidence. Mean N\(_2\) concentrations measured were 774 mg l\(^{-1}\) in the 4 day treatment and 523 mg l\(^{-1}\) in the 8 day treatment. Emissions of the environmentally damaging N\(_2\)O gas were quantified as being 514 mg l\(^{-1}\) in the 4 day treatment and 219 mg l\(^{-1}\) in the 8 day. The lower emissions from the 8 day treatment are attributed to improved contact between oxygen and slurry, reducing the prevalence of zones favourable for denitrification. In the final mass balance study, overall nitrogen leaving the system equalled 86 (±18) % of that entering in the 2 day treatment, 113 (±10) % in the 4 day treatment, and 104 (±21) % in the 8 day treatment. The variation in values was attributed to errors in the liquid phase analysis of slurry nitrogen compounds.

When non-Newtonian fluids are mixed in a stirred tank at low Reynolds numbers caverns can be formed around the impeller. If the fluid contains a yield stress the cavern has a fixed boundary where no flow occurs outside of it. When the fluid does not contain a yield stress a pseudo-cavern is formed, the cavern boundary is not fixed since flow can occur outside of it, but the majority of the flow is present in a region around the impeller. Mixing and cavern formation of a variety of non-Newtonian fluids are studied using experimental techniques and computational fluid dynamics (CFD). Cavern data extracted from both methods are compared with mechanistic cavern prediction models. An adapted planar laser induced fluorescence technique showed that mixing inside of a shear thinning Herschel-Bulkley fluid is very slow. Positron emission particle tracking obtained flow patterns and cavern sizes of three rheologically complex opaque fluids. CFD was able to predict the data obtained from both experimental techniques fairly well at low Reynolds numbers. A toroidal cavern model provided the best fit for single phase fluids but for the opaque fluids all models drastically over predicted the cavern size, with the cylindrical model only predicting cavern heights at high Reynolds numbers.