In this thesis, an integrated monitoring device for use on 11 kV overhead lines has been developed. Uniquely, the devices use an optimised form of Power Line Communication to enable a low latency communication network. It is shown that such a network is able to facilitate new and improved applications and offer tangible benefits to the network operator.

Fostering the nation‘s innovation is the key role of public research and development (R&D). However, executive staffs of public R&D organisations worldwide are continuously faced with the challenge of planning innovation orientation to attain their vision. There is a need for developing the innovation model in the context of public R&D. Furthermore, these challenges are exacerbated by continuous changes in citizens‘ social aspirations and industries‘ expectations in a turbulent economic climate of any developing economy. The main objective of this research is to provide a methodological framework which assists in structuring an innovation management model taking all dimensions of public R&D into account. To accomplish the main objective, the research involves the following theoretical and empirical studies: (a) using the Delphi method in refining influencing factors on innovation management in public R&D gathered from a literature review; (b) using the Analytic Hierarchy Process (AHP) to propose a management model which hierarchically arranges the refined factors involving multiple dimensions of public R&D ; (c) applying the proposed innovation management model for devising an adapted orientation for future innovation in a case study; (d) providing an illustrative model for generic deploying the research findings to other socio-organisational contexts. As innovation development in R&D organisations is influenced by national contexts within which the R&D is operated; Delphi experts are selected from various national research centres of a particular county, i.e. Thailand. In addition, the AHP application is performed in a Thai case study for in-depth exploration of a particular phenomenon. The AHP findings assist in formulating a proper orientation for organisational innovation plans compared to methods used at present based on intuition. In addition, the hierarchy model and its factors could form a valuable resource for better planning a cohesive innovation orientation in the selected country. Moreover, the proposed methodological framework (involving a combined Delphi and AHP) is adaptable to users from other countries and contexts. It has the potential to assist in delivering effective innovation management their organisation.

A study has been taken to investigate the channel development especially fluvial river with meandering thalweg. The study included the physical model with steady inflow and unsteady inflow in the lab, and numerical model to simulate the development process, considering the bank erosion and secondary flow. In the study of channel development with physical model, a series of tests have been carried out to model the fluvial river with different flume slope, flow rate and channel section size. The meandering thawleg channel development process was carefully observed and from results in the lab, channels only had curved boundaries with meandering thalweg, not the real meandering river. Many characteristics of fluvial river in the nature like ripple- pool unit, point bar have been modelled successfully. Then different parameters like slope, flow rate and channel size were tested independently to see their effect on channel morphology. From experiments, it is confirmed that slope is key factor to distinguish straight, meandering and braided channels. Flow rate and section size were also discussed. From the discussion of different controlling parameters, it is found that the essential control factor is Froude number. Tests with unsteady inflow were then carried out to model the real hydrology process as that in nature. Gradually varied unsteady inflow and rapidly varied unsteady inflow were achieved by controlling the frequency of pump. Bed profile of channel after operation was recorded by Bed Profiler. Developments tell that steady inflow could deep channel and unsteady inflow has more effect on bank erosion and makes channel wider. It is concluded from bed profiles, steady inflow produces stable ripples, smooth point bars, curved channel banks. Rapidly varied flow got straight channel, wider upstream. Gradually varied flow got unstable ripple in the main channel and deepest pools. Finally numerical modelling considering bank erosion and secondary flow was developed to simulate the tests. Bank erosion model comes from previous research and secondary flow was considered based on the balance of force in the transverse direction on Cartesian coordinate system without the constraint of constant radius of curvature. The modelling results have a good agreement with physical model for steady inflow and unsteady inflow with different channel size and slope.

This thesis reports on the evaluation of performance and behaviour of earth electrode systems subjected to DC, AC and transient current injections with different rise times and shapes. The performance of the earth electrode system when injected with currents at the power frequency is now well understood, but the response of the system under high frequency and transient conditions is yet to be fully clarified. This thesis contributes to the better understanding of complex earthing systems such as earth grids and wind turbine earthing system behaviour under high frequency and transient conditions including voltage distributions along the length of the electrode. The frequency and time domain responses of earth electrodes (vertical and horizontal earth electrodes and earth grids) were quantified for soil resistivity ranged from 10Ωm to 10kΩm. Practical wind turbine earthing system models were developed to account for the additional effects of the above–ground tower structure of the wind turbine and also to consider the benefits of various enhancements to the earthing system. Simulations using 1/5μs and 8/20μs impulse currents were carried out, and a number of parameters were quantified; these include the earth potential rise and the voltage distributions at ground surface level. In particular, the contribution of mitigating techniques, such as rings and rods were derived. The computations allowed determination of touch and step voltages. The results show that the performance of an earth electrode depends on a number of factors such as soil resistivity and permittivity and electrode dimensions, and it was found that significant inductive effects dominate at high frequency. Thus, the ability of a horizontal earth electrode to reduce the earth potential rise is limited because, beyond a certain length known as the effective length, no further reduction is obtained. The effective length was determined experimentally by incrementally increasing the length of the test electrode. The experimental and simulation results show reasonably close agreement. Furthermore, reasonable prediction of the effective length may be possible using simple empirically derived equations. The thesis proposes a new method to increase the effective length of in-ground horizontal earth electrodes and the effective area of earth grids. It is proposed that an additional insulated parallel an above ground conductor is bonded to the horizontal electrode at suitable points along its length. Field tests show that the addition to such enhancement reduces inductance effects and helps dissipation of injected currents, so that a greater length of buried earth conductor is utilised, and this contributes to an additional reduction in the earth impedance. Hence, the earth potential rise at the point of current injection is reduced. Enhancing the earthing system in this way results in a significant reduction in the transient potentials developed at the base of the turbine structure. These TEPR reductions produce associated reductions in touch and step voltages.

This thesis looks at how the Radio Frequency (RF) waveform measurement and engineering techniques developed for Power Amplifier (PA) design can be used to investigate RF reliability. Within this area two major themes are concentrated on – firstly the effect of a load impedance mismatch and secondly an investigation into using the RF IV waveform measurement system for RF stress testing. The initial aim for this work was to investigate the potential for removing the output protection isolator from a PA. It was seen that in doing so there is the potential to cause an impedance mismatch, which results in a portion of the power produced being reflected back. It was shown that the conditions that could be presented to a device as a result of an impedance mismatch can be found by performing a Voltage Standing Wave Ratio (VSWR) sweep. The results of the worst possible case scenario VSWR sweep, when all of the power is reflected back, can be split into three regions. One of high RF drain voltage swings, one of high RF drain currents and a transition region of simultaneously high RF drain currents and voltage swings. Each of these regions presents different operating conditions to the device, and in turn different stresses. The second part of this thesis concentrates on an investigation into Gallium Nitride (GaN) Heterostructure Field Effect Transistor (HFET) reliability, specifically if the RF waveform measurement system can be used to provide detailed information about the state of the device during RF stress testing. A stress testing procedure was developed to allow this, which featured both DC and RF characterisation measurements before and after every stress period. It was shown that the measurements made during the characterisation stages only gives a representation of the degradation seen in the same measurements during the RF stress period.

This project continues the work of Daniel White which culminated in the thesis, "A Hot Strip Mill Work Roll Temperature Model", submitted to Cardiff University in 2007. The current project presents a combined thermal solution, incorporating a transient, two-dimensional model which predicts changes in the circumferentially averaged temperature profile with time, and a static, three-dimensional model which provides high-resolution results near the surface of the roll and uses the results of the two-dimensional model as boundary conditions. The material properties of both models can now exhibit temperature dependency and boundary conditions at the surface have been improved. The resolution of the static model has been increased dramatically after testing found that the temperature profile was being compromised. The stress models use ABAQUS, a finite element software package, and have been completely redesigned. The stress solution consists of three models, each successive model concentrating more resolution on the roll bite, using the sub-modelling technique. Temperature data is imported from the thermal models, mechanical loads are applied using process data taken from the hot mill database at Port Talbot and residual loads are applied using the best currently available experimental data. Residual and thermal stresses were found to be significant, but the mechanical loads made little difference to the peak or minimum stresses per roll revolution. A brief investigation showed that, for a high-reduction rolling schedule (40% reduction rates), increasing the work roll oxide layer thickness from 3μm to 10μm decreases the cyclic stress range by roughly 100MPa. Taking account of temperature variability in the material properties also made roughly 100MPa difference to the stress range. The radial temperature distribution in the roll was shown to have a strong effect on the stresses at the roll surface, with a cold roll core incurring large peak stresses for the same circumferential temperature profile.

A micromechanical constitutive model for concrete is proposed in which microcrack initiation, in the interfacial transition zone between aggregate particles and cement matrix, is governed by an exterior-point Eshelby solution. The model assumes a two-phase elastic composite, derived from an Eshelby solution and the Mori-Tanaka homogenization method, to which circular microcracks are added. A multi-component rough crack contact model is employed to simulate normal and shear behaviour of rough microcrack surfaces. It is shown, based on numerical predictions of uniaxial, biaxial and triaxial behaviour that the model captures key characteristics of concrete behaviour. An important aspect of the approach taken in this work is the adherence to a mechanistic modelling philosophy. In this regard the model is distinctly more rigorously mechanistic than its more phenomenological predecessors. Following this philosophy, a new more comprehensive crack-plane model is described which could be applied to crack-planes in the above model. In this model the crack surface is idealised as a series of conical teeth and corresponding recesses of variable height and slope. Based on this geometrical characterization, an effective contact function is derived to relate the contact stresses on the sides of the teeth to the net crack-plane stresses. Plastic embedment and frictional sliding are simulated using a local plasticity model in which the plastic surfaces are expressed in terms of the contact surface function. Numerical simulations of several direct shear tests indicate a good performance of the model. The incorporation of this crack-plane model in the overall constitutive model is the next step in the development of the latter. Computational aspects such as contact related numerical instability and accuracy of spherical integration rules employed in the constitutive model are also discussed. A smoothed contact state function is proposed to remove spurious contact chatter behaviour at a constitutive level. Finally, an initial assessment of the performance of the micromechanical model when implemented in a finite element program is presented. This evaluation clearly demonstrates the capability of the proposed model to simulate the behaviour of plain and reinforced concrete structural elements as well as demonstrating the potential of the micromechanical approach to achieve a robust and comprehensive model for concrete.

In the simulation of the Tunnel Sealing Experiment the behaviour of the clay bulkhead is investigated with a limited amount of experiment evidence available. Preliminary comparisons with the observed behaviour show that the thermal field is slightly over predicted. However, key trends in the mechanical response are identified and the hydraulic behaviour is captured reasonably well.

The objectives of this research were to investigate the impact of electric vehicle battery charging on grid demand at a national level and on the steady state parameters of distribution networks. An agent-based control system that coordinates the battery charging of electric vehicles according to electric vehicle owner preferences, distribution network technical limits and electricity prices was designed and developed and its operation was tested experimentally. The impact on grid demand peak increases at the national systems of Great Britain and Spain was evaluated using low and high electric vehicle uptake levels of 7% and 48.5% of the car fleet for the year 2030 with a deterministic method. It was found that a low uptake will not raise significantly the grid demand peaks in both countries under investigation. However, a high uptake will raise significantly the grid demand peaks. The impact from residential electric vehicle battery charging on steady state voltages, power line losses, transformers’ and cables’ loadings of distribution networks was evaluated using a deterministic and a probabilistic method. It was found that low and medium uptake levels of electric vehicles equivalent to 12.5% and 33% per residential area of 384 customers in 2030, can be safely accommodated by reinforcing the distribution network. A combination of reinforcements, installation of microgenerators and control of electric vehicle battery charging will be required to accommodate safely a high uptake of 71% with regards to the constraints studied. An agent-based control system that coordinates the battery charging of electric vehicles was designed and developed. Search techniques and neural networks were used for the decision making processes. The ability of the agent-based control system to operate successfully in both normal and abnormal conditions for the electrical network was proved with experimental validation in the laboratory of Tecnalia research institute in Spain.

Ribbed reinforcement is described as “high bond” in Eurocode 2 (EC2) and within the code serviceability checks make no allowance for variations in either the ductility or bond characteristics of these bars. In this work, this matter is explored, and the crack development and behaviour of concrete beams reinforced with various types of ribbed steel bar are investigated, using both numerical and experimental approaches. The objective of the experimental approach is to undertake a series of experiments to compare the performance of beams made with standard reinforcement with that of beams formed with a new high-ductility bar produced by CELSA UK. The relationship between the bond strength and the rib pattern of reinforcing steel was studied and the behaviour at SLS load levels of RC beams with reinforcement of different rib patterns in flexure is discussed. The cracking of beams was monitored both visually and using a non-destructive Digital Image Correlation system to trace in-plane deformations and strains on the surface of the specimens. The test results showed that specimens with bars which had the highest relative rib area (fR value) exhibited the smallest crack spacing and crack width. A numerical model was developed to explore the crack development of reinforced concrete beams under flexural loading. The model employed a non-linear material model for concrete and a smeared crack approach. In order to address the well known numerical stability problems, associated with softening models, a non-local gradient method was used. Crack widths cannot be obtained directly from such models, due to the diffuse nature of non- local simulations, therefore a post-processing procedure was developed to allow the crack characteristics to be calculated. Several numerical examples are presented to illustrate the satisfactory performance of the model. In addition, a series of numerical simulations of the BOND AND CRACKING OF REINFORCED CONCRETE Simon H.C. Chan Page vi experimental beams tested in the present study were used validate the numerical model and conversely, to provide confidence in the consistency of the experimental results.