This investigation presents research on the characteristic properties of Nylon66 and poly(ethylene naphthalate) (Ny66/PEN), and poly(butylene terephthalate) and poly(ethylene naphthalate) (PBT/PEN) blends with several weight compositions made by melt blending, by the use of 13C and 1H Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC) and Dynamic mechanical thermal analysis (DMTA), X-ray diffraction (X-RD), tensile, impact and stress relaxation tests. Ny66/PEN blends including several additives do not improve the miscibility of the constituent polymers and show lower tensile strength than those of homopolymers. However, PBT/PEN blends reveal improved tensile strengths of the blends between the ROM and MROM predictions lines with more than 50 % volume fraction of PEN. On the other hand, NMR spectra show no evidence of interchange reaction in both Ny66/PEN and PBT/PEN blends. SEM micrographs of fracture surfaces in PBT/PEN blends reveal a very small (sub-micron) domain size in contrast to large domains in Ny66/PEN blends, which indicates partial miscibility of PBT and PEN. DSC and DMTA demonstrate partial miscibility of PBT/PEN blends by the change of Tgs of each component according to the weight proportions of the constituent polymers. Stress relaxation tests for the specimens of PBT/PEN blends and the homopolymers, using the Taguchi method of experimental design, determine that the most significant factor is the temperature, followed by PEN content and then the initial stress, and interaction effects between factors are insignificant. To fit the relaxation curves of the PBT/PEN blends and the homopolymers at different temperatures, PEN contents and initial stresses, four different equations have been used. The coefficients of the equation that fit best are used to predict the relaxation behaviour of PBT/PEN blends at a temperature between 30C and 60C, and at the initial stresses of 7 MPa.

It is crucial to understand the fundamental mechanisms of cleaning milk protein fouling to optimise Cleaning-in-place (CIP) process. Using Whey Protein Concentrate (WPC) gel as a model material and a rapid ultraviolet (UV) spectrophotometry, a comprehensive laboratory study on the cleaning of the WPC gel deposits from hard surface with alkaline cleaning solutions has been conducted. The kinetics of the cleaning process has been established and mathematical models have been developed in order to elucidate the influences of various parameters on cleaning process. This study has provided sound evidence that whey protein concentrate gel is a reliable simulation of the whey protein fouling deposits used in most milk protein fouling and cleaning studies. Based on treating denatured whey protein gels as biopolymers, a chemical reaction controlled polymer dissolution cleaning mechanism has been proposed. The polymer dissolution plays a major role of removing proteinaceous deposits when treated with alkaline solutions under the flow conditions tested. Similar to the diffusion of cleaning chemicals and chemical reactions, the reptation (induction) is also one of essential steps for the dissolution of WPC gels in alkaline solutions. The disengagement of intermediate reaction products (altered protein molecules) from a gel-solution interface and subsequent mass transfer of these reaction products to the bulk cleaning solutions are the rate-limiting steps for the cleaning process. The typical dissolution cleaning rate curve of WPC gels in alkaline solutions includes swelling, uniform and decay cleaning stages. This study on cleaning kinetics shows that increasing the cleaning temperature can improve the cleaning efficiency. The apparent activation energy for these three stages is 32.6, 40.5, and 38.3 kJ/mol, respectively, which is in agreement with previous research works. Increasing flow velocity enhances the cleaning process. However, this effect could be reduced when and the cleaning process gradually changes from a mass transfer-controlled process to a disengagement-controlled process, where the flow velocity is very high. The introduction of the hydrolysis, β-elimination reactions and some competing chemical reactions have highlighted the complex of chemical reactions involved in cleaning of proteinaceous fouling using alkaline solutions. The changes in molecular mass distribution and SH content of WPC gel dissolved at various temperatures observed has confirmed the assumption that all these chemical reactions are temperature dependent. The investigation on the swelling, microstructural and mechanical properties of WPC gels treated with alkaline solutions also illustrates the concentration dependency of these chemical reactions. The mechanical property studies demonstrate that the chemical treatment could make WPC gel weaker and easier to be destroyed. However, the relationship between the mechanical properties and the cleaning process needs to be further studied. Based on the polymer dissolution and mass transfer theory, a mathematical model of chemical cleaning has been proposed. Various parameters, such as tr (reptation time), Rm, (constant cleaning rate), mc, (the critical mass), ξ (rate constant in swelling stage), kA (rate constant in decay stage) and Ψ (a dimensionless parameter) have been used to characterise the whole cleaning process. Among the parameters used in the cleaning model, the constant cleaning rate (Rm) is the most important one and determines the overall efficiency of a cleaning process, which has been further predicted and expressed as a product of mass transfer coefficient and solubility of disengaged protein molecules. The successful model formulations for the cleaning rate and cleaning time under various operation conditions are a good outcome of the rational mechanisms proposed for the removal of proteinaceous fouling. This research has provided a good foundation for further fundamental research in this area and for optimising the cleaning processes.

A technique has been developed that allows the gasification reaction rates of representative samples of carbon-carbon composite materials to be examined. The technique involves heating the sample in a controlled and monitored environment; the product gases of the reaction are then analysed by a mass spectrometer, allowing their identification and quantification. The technique was used to characterise the oxidation reactions of cathode carbons. These materials are composites and so the oxidation reactions of their constituent raw materials were also examined. Surface area was determined for each sample, allowing specific rates of reaction to be determined, normalising surface area effects. The anodes, cathodes and sidewalls of aluminium smelting cells are made of composite carbon materials comprising filler materials (such as coke, anthracite and graphite) and a binder (almost exclusively coal tar pitch). Whilst the oxidation of anode carbons has received extensive study the oxidation reactions of cathodes have been neglected largely because they have not been a cause of smelting cell failure. However, with the longer lives now being achieved from smelting cells the long term degradation reactions, such as oxidation, will have to be considered. Oxidation of cathodes in the area of the collector bar will increase resistance and affect the heat balance of the cell. Gasification reactions of carbon materials are frequently characterised using techniques such as thermal gravimetric analysis (TGA). These techniques are accurate for examining such reactions when the sample is of small size and a single carbon type. To characterise composite carbons correlations have been made between the overall oxidation resistance (determined by weight loss) and the ignition temperature of one of the constituent materials (determined by TGA). The results obtained using the new technique of product gas analysis (PGA) revealed an exponential dependence of oxidation rate on temperature for the carbons examined. At higher rates the limiting condition appeared to be mass transfer through the pores of the sample. Arrhenius plots of reaction rates allowed the activation energy of oxidation to be determined for each material. When the rate was controlled by the chemical reactivity of the material the activation energies determined agreed well with values obtained from the literature. The two graphites examined had activation energies of 164 and 183 kJ.mol-1, Ea of graphite has been measured in the range 175-281 kJ.mol-1, the latter figure being for a highly pure graphite. For the two anthracites Ea was ll3 and 118 kJ.mol-1, literature values have it between 100 and l5l kJ.mol-1. The pitches, used as binders of cathode carbons, had Ea equal to 112 and 123 kJ.mol-1, values from the literature range from 121-165 kJ.mol-1. Activation energies were determined for the cathode materials, and were clearly influenced by the reactivity of the constituent materials. An amorphous cathode carbon, having nominally 30% graphite, had an activation energy of 121 kJ.mol-1. A semigraphitic cathode material comprising 100% graphite in a pitch binder had an activation energy of 123 kJ.mol-1. The similarity of these values to those for Ea of the pitch and anthracite indicates that the binder phase is having a strong influence on cathode reactivity. These values of Ea accord well with values determined for similar samples, reported in the literature ranging from 114 to 138 kJ.mol-1. A semigraphitised cathode material had an activation energy of 176 kJ.mol-1 in the same range as that of graphite. This sample oxidised significantly less rapidly at all temperatures. The variation in reactivity of the constituent materials of cathode carbons accounts for the highly selective oxidation behaviour observed in these materials. Porosity development is rapid as binder matrix is preferentially oxidised, leading to an acceleration of oxidation rate with increasing burnoff. The rate begins to decelerate once all the binder matrix has been oxidised, the residue being less reactive than the starting material. The structure of the materials was quantified using X-ray diffraction (XRD). A peak ratio method was employed, comparing the intensify of the 4oz peaks of cathode carbons and a standard electrographite. Once effects of cathode porosity had been normalised an excellent correlation between increasing peak intensity ratio and increasing oxidation resistance was found.

This thesis describes an investigation into the flow behaviour of particulate solids and capsules in wood pulp fibre suspensions. Emphasis is placed on measuring pipe friction loss and stability of solids-fibre slurries and fibre-capsule mixtures in straight horizontal pipes. It is shown that low concentrations (1-3 %v) of wood pulp fibre form a structured carrier fluid with ability to support particles while behaving like a liquid of low viscosity. At moderate flow velocities fibres damp turbulence and friction losses become lower than water. If solids are preferentially injected into the fibre suspension as a central core, or in a capsule as dry solids, pipe friction loss is reduced further, as is pipe wear. At very low fibre concentrations (<1%v), fibres reduce the friction loss of conventional solid-water mixtures and act as a drag reducing additive. The network strength properties of five wood fibre suspensions are reported and their application to slurry flow is discussed. Settling data for particulate solids, coherent dense-phase cores and capsules are presented and various mechanisms of support are described. Two flow techniques for transporting coarse and dense-phase particle suspensions are proposed, along with strategies for injecting solid particulates into a pipeline. Pipe friction loss data are presented for solids-fibre mixtures of wood chips (7-15 mm), coarse (+2-10 mm) and fine (+0.5-1.0 mm) coal, sand (+0.32-2.0 mm), iron ore (+0.05-0.28 mm), and cylindrical capsules (loaded with dry solids) flowing in 54, 79 and 101.6 mm diameter PVC pipes. Some pipe friction loss data are presented for solids transported as a central core supported by an annulus of fibre suspension. The key flow parameters are also optimized and a preliminary cost comparison is made. Coarse coal suspensions (up to 4O %v) with fibre concentrations of 0.7 to 1.0 percent have been shown to exhibit friction losses about 40 percent below that of the equivalent coalwater slurry. Adding 0.8 percent fibre to water is shown to reduce capsule friction head loss up to 50 percent.

This thesis describes an investigation into the flow behaviour of particulate solids and capsules in wood pulp fibre suspensions. Emphasis is placed on measuring pipe friction loss and stability of solids-fibre slurries and fibre-capsule mixtures in straight horizontal pipes. It is shown that low concentrations (1-3 %v) of wood pulp fibre form a structured carrier fluid with ability to support particles while behaving like a liquid of low viscosity. At moderate flow velocities fibres damp turbulence and friction losses become lower than water. If solids are preferentially injected into the fibre suspension as a central core, or in a capsule as dry solids, pipe friction loss is reduced further, as is pipe wear. At very low fibre concentrations (<1%v), fibres reduce the friction loss of conventional solid-water mixtures and act as a drag reducing additive. The network strength properties of five wood fibre suspensions are reported and their application to slurry flow is discussed. Settling data for particulate solids, coherent dense-phase cores and capsules are presented and various mechanisms of support are described. Two flow techniques for transporting coarse and dense-phase particle suspensions are proposed, along with strategies for injecting solid particulates into a pipeline. Pipe friction loss data are presented for solids-fibre mixtures of wood chips (7-15 mm), coarse (+2-10 mm) and fine (+0.5-1.0 mm) coal, sand (+0.32-2.0 mm), iron ore (+0.05-0.28 mm), and cylindrical capsules (loaded with dry solids) flowing in 54, 79 and 101.6 mm diameter PVC pipes. Some pipe friction loss data are presented for solids transported as a central core supported by an annulus of fibre suspension. The key flow parameters are also optimized and a preliminary cost comparison is made. Coarse coal suspensions (up to 4O %v) with fibre concentrations of 0.7 to 1.0 percent have been shown to exhibit friction losses about 40 percent below that of the equivalent coalwater slurry. Adding 0.8 percent fibre to water is shown to reduce capsule friction head loss up to 50 percent.

This thesis describes an investigation into the flow behaviour of particulate solids and capsules in wood pulp fibre suspensions. Emphasis is placed on measuring pipe friction loss and stability of solids-fibre slurries and fibre-capsule mixtures in straight horizontal pipes. It is shown that low concentrations (1-3 %v) of wood pulp fibre form a structured carrier fluid with ability to support particles while behaving like a liquid of low viscosity. At moderate flow velocities fibres damp turbulence and friction losses become lower than water. If solids are preferentially injected into the fibre suspension as a central core, or in a capsule as dry solids, pipe friction loss is reduced further, as is pipe wear. At very low fibre concentrations (<1%v), fibres reduce the friction loss of conventional solid-water mixtures and act as a drag reducing additive. The network strength properties of five wood fibre suspensions are reported and their application to slurry flow is discussed. Settling data for particulate solids, coherent dense-phase cores and capsules are presented and various mechanisms of support are described. Two flow techniques for transporting coarse and dense-phase particle suspensions are proposed, along with strategies for injecting solid particulates into a pipeline. Pipe friction loss data are presented for solids-fibre mixtures of wood chips (7-15 mm), coarse (+2-10 mm) and fine (+0.5-1.0 mm) coal, sand (+0.32-2.0 mm), iron ore (+0.05-0.28 mm), and cylindrical capsules (loaded with dry solids) flowing in 54, 79 and 101.6 mm diameter PVC pipes. Some pipe friction loss data are presented for solids transported as a central core supported by an annulus of fibre suspension. The key flow parameters are also optimized and a preliminary cost comparison is made. Coarse coal suspensions (up to 4O %v) with fibre concentrations of 0.7 to 1.0 percent have been shown to exhibit friction losses about 40 percent below that of the equivalent coalwater slurry. Adding 0.8 percent fibre to water is shown to reduce capsule friction head loss up to 50 percent.

This thesis describes an investigation into the flow behaviour of particulate solids and capsules in wood pulp fibre suspensions. Emphasis is placed on measuring pipe friction loss and stability of solids-fibre slurries and fibre-capsule mixtures in straight horizontal pipes. It is shown that low concentrations (1-3 %v) of wood pulp fibre form a structured carrier fluid with ability to support particles while behaving like a liquid of low viscosity. At moderate flow velocities fibres damp turbulence and friction losses become lower than water. If solids are preferentially injected into the fibre suspension as a central core, or in a capsule as dry solids, pipe friction loss is reduced further, as is pipe wear. At very low fibre concentrations (<1%v), fibres reduce the friction loss of conventional solid-water mixtures and act as a drag reducing additive. The network strength properties of five wood fibre suspensions are reported and their application to slurry flow is discussed. Settling data for particulate solids, coherent dense-phase cores and capsules are presented and various mechanisms of support are described. Two flow techniques for transporting coarse and dense-phase particle suspensions are proposed, along with strategies for injecting solid particulates into a pipeline. Pipe friction loss data are presented for solids-fibre mixtures of wood chips (7-15 mm), coarse (+2-10 mm) and fine (+0.5-1.0 mm) coal, sand (+0.32-2.0 mm), iron ore (+0.05-0.28 mm), and cylindrical capsules (loaded with dry solids) flowing in 54, 79 and 101.6 mm diameter PVC pipes. Some pipe friction loss data are presented for solids transported as a central core supported by an annulus of fibre suspension. The key flow parameters are also optimized and a preliminary cost comparison is made. Coarse coal suspensions (up to 4O %v) with fibre concentrations of 0.7 to 1.0 percent have been shown to exhibit friction losses about 40 percent below that of the equivalent coalwater slurry. Adding 0.8 percent fibre to water is shown to reduce capsule friction head loss up to 50 percent.