This thesis presents the development of a reactive gas transport equation under coupled framework of thermal, hydraulic, chemical and mechanical (THCM) behaviour of variably saturated soil. The capabilities of theoretical and numerical modelling of THCM processes have been advanced by the successful implementation of various aspects of the new addition. The previously developed THCM model at the Geoenvironmental Research Centre (GRC) has been extended to include the multicomponent gas transport modelling coupled with chemical/geochemical processes. The mechanisms of advection and diffusion have been considered to define the transport of multicomponent gas and chemicals in respective phases as well as exchange via dissolution and exsolution. The governing mass transfer process is subjected to homogeneous and heterogeneous geochemical reactions under equilibrium condition. Numerical solutions of the governing flow and deformation equations have been achieved by employing finite element method for spatial discretisation and finite difference method for temporal discretisation. Advanced geochemical features of gas-chemical interactions have been incorporated in the transport model, COMPASS by coupling with the geochemical model PHREEQC. A sequential non-iterative approach has been adopted to couple the transport processes and geochemical interactions. Verification of various aspects of the developed gas transfer equation has been commenced via a number of simulation exercises. Good agreement between the results have been achieved which suggests accurate and successful implementation of the theoretical and numerical formulation. The model has been implemented to investigate the gas transport processes in variably saturated compacted clay buffers via a number of conceptual simulation scenarios which are representative of high level nuclear waste disposal. Simulation of gas migration through saturated buffer has been intended to investigate the maximum pressure development as well as the dominant flow mechanisms. Demonstration of the modelling capability in context of reactive gas transport has been carried out considering long term isothermal flow of hydrogen through unsaturated clay buffer. The conclusions drawn from the discussions of simulation results has favoured the understanding of some of the key issues associated with gas generation and migration in compacted porous media, particularly, as a case of high level nuclear waste disposal.

This work is primarily concerned with the performance of tower base earthing systems under AC variable frequency and transient conditions. The work has involved the investigation into the performance of practical earthing systems including tests on a full-size 275kV transmission tower base and corresponding calculation and numerical simulations.

The principal aim of this thesis is the investigation of the electrical properties of conducting pigments provided by Merck KGaA. These pigments are generally micron-sized mica particles coated with a transparent conducting oxide (TCO) and are conventionally dispersed in a polymer matrix at varying volume fractions to form composite structures. To measure the electrical properties of composites and powder materials is not easy since one cannot simply attach terminals as in the measurement of bulk materials. We therefore turn to high frequency techniques, which are capable of measuring composites and powders of conducting particles, but are also capable of measuring non-conducting particles. This thesis therefore has three main themes; 1) the development and use of high frequency measurement techniques for the application to Merck pigments, 2) the investigation of the fundamental electrical properties of TCOs, and 3) the study of the complex electrical behaviour of composites.

The thesis provides practical contributions via the m-Government Adoption Model and associated recommendations. The Researcher believes these will allow Oman's decision-makers to understand the reasons for the lack of e-Government success to date, and by implementing the m-Government critical success factors in the short- to medium-term, move towards successful e-Government in the longer term. It also makes a methodological contribution to the literature via an adoption and diffusion framework amalgamating elements from existing theories developed in the West, to investigate the prevailing situation in a developing country in respect of m-Government initiatives.

The Water Framework Directive (WFD) 2000/60/EC is set to overhaul the management of the water environment within the EU. Following its enforcement in 2015, changes are expected to the current water related regulations and water intensive industries, including steelworks, ought to prepare themselves for changes. In 2007 Corus Group was taken over by Tata Steel, now one of the World’s top 10 steel producers with its production of 31 MTPA (million tonnes per annum of crude steel). Tata Steel Port Talbot Integrated Steelworks is one of Tata Steel’s main sites, currently producing some 4.33 MTPA (in 2007) of crude steel (slab) and is a major user of water with its 8 production facilities and supporting functions. From 2007 to 2011 the author worked as a core member of the World Steel Association Water Management Project. The project included development of a survey to gather water-related data from the World’s steelworks. 29 steelworks took part in the survey and using the data, an extensive assessment of water related performance in steelworks around the World has been carried out. The findings show that water performance related figures, including water use and effluent generation, vary from under 1 to near 150 m3/ts. The average consumption figure being 28.4 m3/ts with once-through cooling using an average 82% of this water. The average effluent discharge figure is 25.4 m3/ts. For Port Talbot Steelworks these figures are 33.8 m3/ts and 28.8 m3/ts respectively. An investigation into effluent treatment technologies and efficiencies included carrying out chemical precipitation and co-precipitation titration experiments, especially looking at zinc, in order to better understand the behaviour of relevant metals during hydroxide precipitation reactions. The experimental results were compared against PHREEQCi theoretical geomodelling precipitation prediction data and PHREEQCi 2 indicated minimum zinc solubility is received at pH 9.5. Laboratory experiments support this. Iron enhances zinc precipitation strongly via co-precipitation. A similar effect, although to a lesser extent, is achieved for zinc co-precipitation with nickel and lead. The author’s study of the Port Talbot water systems established that the chemical precipitation processes in operation leads to the generation of voluminious sludge that is hard to dewater further. This prompted the initiation of an investigation into the suitability of the High Density Sludge (HDS) process in treating high volume, non-acidic low metal concentration effluents, such as steelworks final effluent. Prior to this research the HDS process has been used mainly for the treatment of mine effluents and its suitability in treating non-acidic, low metal concentration effluent has not been fully explored. During the trial, a 10 L/h influent feed rate was aimed for with a half hour retention time at the first two reactors. The flocculant feed rate was around 2.5-3 mg/l of treated effluent throughout the trial. At the end of the trial the sludge concentrations exceeded 17% (w/w), while the treatment efficiencies of zinc and other metals stabilised and improved. Furthermore, the sludge was behaving as HDS sludge achieving high settling rates in excess of 22 m/h at 5% (w/v). Solids concentrations and sludge filterability had improved with the specific cake resistance reducing from the ‘single pass’ precipitation sludge near 35,000 Gm/kg to the 777 Gm/kg after 2 weeks of trial to a mere 169 Gm/kg at the end of the HDS trial.

This thesis examines the role of Acoustic Emission (AE) as a non-destructive testing (NDT) technique for prestressed and reinforced concrete structures. The work focuses on the development of experimental techniques and data analysis methods for the detection, location and assessment of AE from prestressed and reinforced concrete specimens. This thesis reveals that AE can be used to detect the onset of corrosion activity in wire in the interface between prestressed concrete and mortar as found in prestressed concrete pipes. Furthermore, this technique can be used to locate the corrosion activity on different size prestressed concrete samples. By correlation between three parameters of classical AE analysis techniques (traditional parameters), damage can be detected and located whilst the corrosion area, macro crack and crack propagation can be identified. However, it cannot classify the crack type. Different damage modes, including corrosion activity, micro/macro cracking formation, crack propagation and wire failure generate different types of AE signals with varying amplitudes and absolute energy emitted. A novel analysis approach has been used on composite materials (concrete, mortar and steel) to evaluate differing crack types by a combination of the classical acoustic emission analysis technique and advanced analysis Rise time / Amplitude (RA) and Average Frequency (AF), results proved the effectiveness of the developed techniques for damage detection and classification crack types. The relationship between RA value and AF value can be used to determine the crack area and classify it as either tensile crack type, other type (shear movement) or no crack. The results of the research have demonstrated that the AE technique is valid in larger scale monitoring and hence the potential for monitoring real structures such as prestressed concrete pipes. Use of Kernel Density Estimation Function (KDEF) provides improved visualisation of the data to represent clearly the RA/AF values. Key Words: Acoustic Emission, Corrosion, Reinforced Concrete, Prestressed Concrete, Micro and Macro Concrete Cracks, Crack classification, Source Location, Damage Assessment, Monitoring.

In recent times, several machine learning techniques have been applied successfully to discover useful knowledge from data. Cluster analysis that aims at finding similar subgroups from a large heterogeneous collection of records, is one o f the most useful and popular of the available techniques o f data mining. The purpose of this research is to design and analyse clustering algorithms for numerical, categorical and mixed data sets. Most clustering algorithms are limited to either numerical or categorical attributes. Datasets with mixed types o f attributes are common in real life and so to design and analyse clustering algorithms for mixed data sets is quite timely. Determining the optimal solution to the clustering problem is NP-hard. Therefore, it is necessary to find solutions that are regarded as “good enough” quickly. Similarity is a fundamental concept for the definition of a cluster. It is very common to calculate the similarity or dissimilarity between two features using a distance measure. Attributes with large ranges will implicitly assign larger contributions to the metrics than the application to attributes with small ranges. There are only a few papers especially devoted to normalisation methods. Usually data is scaled to unit range. This does not secure equal average contributions of all features to the similarity measure. For that reason, a main part o f this thesis is devoted to normalisation.

This thesis deals with the numerical simulation of particulate composites using one of the more stable and accurate meshless methods namely the element free Galerkin (EFG) method. To accurately describe the material inhomogeneities present in particulate composites, an extrinsic enrichment function is incorporated into the approximation of the EFG method which produces more versatile, robust and effective computational methodology. The effectiveness of the proposed numerical model is then investigated by employing the model to analyse different configurations of particulate composites. The accuracy and efficiency of this enriched EFG method are studied numerically by comparing the results obtained with the available analytical solutions and other numerical techniques. Further, it is demonstrated that the method developed in this work has the potential to efficiently model syntactic foam, a type of particulate composites. This is illustrated by performing multi-scale modelling using homogenisation technique which confirms satisfactory comparison of the numerical method with experimental results. To further explore the applicability of the developed methodology, an enriched or extended finite element method (XFEM) based technique, is applied to study crack inclusion and interaction of crack propagation with matrix and particles within particle reinforced composite material.

The goal of the research reported in this thesis is to contribute to early and accurate detection of dementia. Early detection of dementia is essential to maximising the effectiveness of treatment against memory loss. This goal is pursued by interpreting the Mini-Mental State Examination (MMSE) in novel ways. The MMSE is the most widely used screening tool for dementia, it is a questionnaire of 30 items. The objectives of the research are as follows: to reduce the dimensions of the MMSE to the most relevant ones in order to inform a predictive model by using computational methods on a data set of MMSE results, to construct a model predicting a diagnosis informed by the features extracted from the previous step by applying, comparing and combining traditional and novel modelling methods, to propose a semantic analysis of the sentence writing question in the MMSE in order to utilise information recorded in MMS examinations which has not been considered previously. Traditional methods of analysis are inadequate for questionnaire data such as the MMSE due to assumptions of normally distributed data. Alternative methods for analysis of discrete data are investigated and a novel method for computing information theoretic measures is proposed. The methods are used to demonstrate that an automated analysis of the MMSE sentence improves the accuracy of differentiating between types of dementia. Finally, models are proposed which integrate the semantic annotations with the MMSE data to derive rules for difficult to distinguish types of dementia.

The objective of this thesis is to provide improved load-pull measurement strategies based on an open-loop active load pull measurement system. A review of the evolution of non-linear measurement systems as well as behavioural model generation approaches has been presented. An intelligence driven active load-pull system has been presented in this thesis, based on deriving local PHD models to aid the prediction of the desired active signal in order to achieve a target reflection coefficient. The algorithm proved to be effective in reducing the number of iterations in an open-loop active load-pull system and thus improving the utilisation efficiency. A non-linear measurement approach suitable for wafer mapping and technology screening applications has also been presented as an application of this new algorithm. In this thesis, it has also been shown how the Cardiff Behavioural model is effective in its ability to interpolate or extrapolate non-linear measurement data and thereby improve the quality of measurement data and speed of measurement systems. This investigation was carried out in two stages; fundamental interpolation testing and harmonic interpolation and extrapolation testing.