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Within the can-making industry there has been a general move from 3-piece cans towards their 2-piece cousins. The majority of this movement has occurred in the beer and beverage sector where virtually all cans are of the 2-piece drawn and wall-ironed variety. This trend has also encroached on the food sector. Where typically a plain 3-piece can was used for packaging foods such as pears, pineapples and tomato products, now a semi-lacquered 2-piece can has started to be used. This work investigates the corrosion mechanisms of these cans using the Scanning Vibrating Electrode Technique (SVET). No previous SVET work detailing the testing of tinplate had been published. The first stage therefore was to develop a testing protocol. This involved finding a suitable electrolyte type and concentration that related to the typical contents of the cans. This was detailed in chapter 3. Following this, development of the SVET equipment was required. This took a number of forms. First an environment chamber was designed and built into the SVET testing stage. Second some further development of the surface profiling technique was carried out. This technique enabled not only the corrosion scanning of formed samples, but also scanning of uneven flat samples that otherwise would have been impossible. This work is detailed in chapter 4. Chapter 5 details the testing of flat production tinplate. A typical tinplate corrosion pattern was discovered that related to the specification of the material. Some questions that surfaced in chapter 5 relating to the SVET detection efficiency were answered in chapter 6. Also detailed in chapter 6 was work carried out on galvanised steels that could be contrasted to the tinplate results. Chapter 7 detailed studies performed on low and high tin coating weight cans. Some excellent and consistent results were achieved. It was possible to relate these results back to the canmaking processing parameters, and the small differences seen between each stage. Chapter 8 provides details of a case study. The SVET was used to predict the corrosion performance of flat tinplate and formed cans. The SVET results were compared to pack test data that showed excellent correlation between the two. Finally chapter 9 details studies in deoxygenated atmospheres. The extra detail revealed on the SVET scans showed that this might well be the direction to take for the future evaluation of tinplate using the SVET. Finally chapter 10 provides conclusions for this first body of work on the study of tinplate using the SVET.

One of the most important contributions to flavour compounds in beer is that associated with the activity of yeast. A kinetic model that quantitatively predicts the influence of changing process parameters on yeast metabolism and the production of flavour compounds would be invaluable. However a review of the literature has revealed that there is an absence of good quantitative data on which to build a model. The literature uses a wide variety of yeast strains and undefined fermentation media. There is also very little quantitative analysis of flavour formation and the models that have been published have little physiological relevance. The aim of the present study was to develop a kinetic model that would describe the production of the higher alcohols, isoamylalcohol and isobutanol, by the yeast N.C.Y.C 1681 within a brewery fermentation system. H.P.L.C., G.C. and enzyme assay analytical methods were developed that allowed the determination of concentrations of pertinent medium components during a fermentation. Amino acid concentrations were determined using Pico-tag (P.I.T.C.) pre-column derivatisation chemistry. Beer volatile components were analysed using G.C. head space analytical procedures. Yeast growth was studied in experimental defined media and in the complex wort medium. The vessels of the study were stirred tank fermenters, tall tubes and brewery cylindroconicals. Higher alcohol production is intimately linked with the yeast populations amino acid metabolism. Thus the influence of medium nitrogen content was investigated in relation to catabolic and anabolic production of higher alcohols.

This thesis presents a finite element solution to the rolling of prepared cane and other two-phase materials. For the first time, modern porous medium mechanics is applied to prepared cane and the rolling and compression of prepared cane is treated as a fully coupled unsaturated-saturated two phase flow problem. The classical Biot theory for fully saturated materials is extended and modified to suit the present project. The finite element method is applied to the governing equations for spatial discretization, followed by both a full rank Newmark scheme and a reduced rank formulation for the time domian discretization. Two analysis methods (steady-state and transient) are presented. The quasi-static <i>.u</i>-<i>P</i> formulation is extensively used in this thesis and verified through numerical computation. Some comments on the implementation of the computer program for the transient direct solution method are also given. A constitutive relation estimated from the finite element simulation of the constrained compression test cell is also given. This is an important contribution of this thesis and leads the way to innovative modelling of milling operations. A more sophisticated finite element inverse analysis method used to determine a constitutive relation for nonlinear two phase materials is also presented, coded and tested. The computational model of the rolling of prepared cane with two rolls is described in detail. The material parameters of prepared cane are described and their variations during the rolling process are derived and discussed. The results of the numerical analysis show that the model and solution procedures are capable of providing realistic predictions and opens the way for further development.

The objective of this work was to remove ethanol from an alcoholic beverage using the aerobic biochemistry of the yeast <i>Saccharomyces cerevisiae </i>and a Dialysis Membrane as an anaerobic/aerobic barrier, between this yeast and the potable beverage. Ethanol, as the carbon substrate is then delivered to the yeast cells by molecular diffusion. To assess the uptake of ethanol as a sole carbon substrate, several stirred tank fermenter (STF) experiments were carried out, with various starting conditions, in particular initial yeast biomass concentration and cell population age. This work showed the benefits of a high initial biomass concentration to minimise batch process time by increasing the rate of bioreaction, mass transfer limitations at the membrane interfacial area having essentially been engineered out in the design of the system, as reported. The benefit of high yeast biomass concentrations are proposed to be dependent on a specific ethanol concentration factor, (per yeast cell), termed the Specific Exposure Factor, (SEF). Through mathematical models developed in this work, mass transfer and bioreaction rates have been assessed, the controlling step being quantified by the dimensionless Kaliber Number <i>(Ka).</i> Through the use of developed dimensionless plots, and comparison of the Monod kinetic parameters given by the models presented, a study of yeast biomass growth and ethanol substrate utilisation is made. Whilst the suppression of yeast growth kinetic performance on ethanol substrate was somewhat variable in the Membrane Bioreactor, the variance did not affect the ethanol substrate uptake kinetic performance of the aerobic yeast cells, which remained remarkably consistent. Ethanol utilisation, (as the limiting carbon substrate), is shown to be by inhibited passive transport at the yeast cell membrane. A comparison of ethanol substrate metabolism to that of glucose has been made.