The power output from a wind turbine is proportional to rotor swept area and as a result in the past 30 years continuous effort has been made to design larger blades. In this period, the blade length has been increased about 10 times since 1980s to present time. With the longest blade currently measuring more than 100m in length, wind turbine blade designers and manufacturers face enormous challenges to encounter the effect of increased weight and other loads on fatigue durability of the blade. Wind turbine blades are mainly made from glass fibre reinforced plastic (GFRP) composite. materials. As a result, in the design of various parts of wind turbine blades such as the shear web, spar cap and the aerofoil the fatigue behaviour of F RP materials is required. The performance of these parts as well as the adhesively bonded joint under fatigue loading is crucial for structural integrity of a long lasting blade. During operation, delamination can initiate and propagate shortening blade life; hence, characterisation of failure envelope of GFRP laminates under different loading mode is necessary. In this regard in this project, quasi-static tests were carried out to find mode 1, mode 11 and mixed mode I/11 delamination fracture toughness using DCB, ENF and MMB tests and the fracture envelope was established for various mode mixity. In the next stage, the stress-lifetime (S-N) diagrams of the GFRP was studied. Fatigue-life experiments on three different types of loading, i.e. tension-tension at R=0.1, 0.5, tension- compression at R=-1 and compression-compression at R=2 and R=10 were performed. From the results of S-N diagrams, the constant life diagrams (CLD) for 90 degree and 0 degree fibre directions were constructed. CLD diagrams are useful for prediction of fatigue lifetime for loading condition that no experimental data available. The analysis of delamination crack propagation under cyclic loading was next area of the research. The onset life and propagation delamination crack grth of 0//0 interface of GR P laminate in mode I loading using DCB specimens was investigated and the Gm. from the onset life test was determined. From the fitted curve to mode I experimental propagation data the Paris’ law coefficient for the laminated GFRP in mode I was determined. The mode II fatigue crack growth in laminated 0//0 GFRP material was also investigated using ENF specimens. The fatigue behaviour in this mode is analysed based on application of Paris’ law as a function of energy release rate for mode II loading. From the fitted curve to experimental data, the Paris’ law coefficient for the laminated GFRP in mode II was determined. The effect of fatigue delamination growth on fracture surface was studied by fractography analysis of SEM images of fracture surfaces. Studying the behaviour of GFRP under cyclic loading and delamination under static and dynamic load led to full-scale testing of wind turbine blade to establish damage tolerance of the blade under cyclic loading. The sensitivity of wind turbine blade to damage has considerable interest for turbine operators and manufacturers. For full-scale fatigue testing, calibration test and modal analysis of a 45.7m blade has been done and moment-strain diagram and natural frequencies of the blade were obtained. Next, the blade sensitivity to damage under fatigue loading was investigated. The blade has been damaged intentionally by initially inserting a crack of 0.2m between the shear web and spar cap and later it was extended to 1m. The effect of these damages on the modal shape, natural frequencies and strains at various locations of the blade were investigated. The damaged blade fatigue tested, the structural integrity and growth of damage were monitored, and the results were discussed. Finally for the improvement of delamination resistance for joints between spar beam and aero-shell stitching method was used. T-beam and box beam joint were chosen as the platform for testing the stitching effect on the delamination. Various pattern of stitching was applied and the optimum pattern was determined.

An investigation of indoor thermal environment has been carried out by computational fluid dynamics approach. The study focuses on the thermal comfort evaluation, particularly the flow and heat transfer effects due to conjugate natural convection, furniture arrangement and occupant number, and flow oscillations. Key physical features of thermo-fluid such as velocity and temperature distributions, thermal sensation maps, and oscillation frequency and its energy are quantified, analysed and compared. The benchmark case study of airflow and heat transfer showed that ANSYS Fluent RNG k - 5 turbulence model with temperature boundary condition on the heated boundary calculated the bestresults, compared with available data. It also showed that air velocity increased along the boundary walls and especially hot wall which led flow direction upwards. At the centre of the flow circulation, air momentum is very weak (e.g. almost zero velocity magnitude). The increase of complex features (6. g. a box with/without heat) in the domain would lead to flow separations causing recirculations above the box and in the rear space of the domain and swirls in the front space presenting three-dimensional flow, and a thermal plume, compared with a two-dimensional clockwise flow in an empty room. The flow recirculations and thermal buoyancy enhanced velocity magnitude and turbulence level in the domain. In fact, the highest frequency was obtained in the room with an unheated box, followed by the room with a heated box. The forrhation of thermal plume from the heated box stabilised the flow in the upper part and the sides of the heated box on a spanwise plane. The frequency of velocity oscillation was consistent with temperature at the location although the energy of the fluctuation is much higher in temperature. Moreover the dominant frequency depended on the orientation of the flow circulation, for example a high energy at a lower frequency on a spanwise plane while a low energy at a higher frequency on a streamwise plane. In an empty room, it was found that there is no direct relation in an empty room (case 3.2.1) between velocity and turbulent flow in power spectral density and frequency, and each of time-history velocity oscillations is independent and random. At the mid- height of the domain, the energy of the velocity fluctuation is relatively weak. The results from the study of conjugate natural convection heat transfer in a ventilated room with localised heat source and window glazing showed that the size of heat source and window glazing, the wall thickness and wall material property are important factors to temperature change and heat loss. For example, 30 % of wall thickness reduction caused 35 % more of heat loss through the wall and 9 % of comfort temperature. From the study of furniture arrangement and occupant number in a 3-D model room with localised heat source and window glazing, it was found that the presence of furniture induced flow recirculation and higher velocity around furniture and the presence of thermal occupant formed thermal plume in the fluid domain, increasing volume-averaged temperature by maximum 15 %, compared with that of unoccupied and empty model room. Increase in the number of occupants and thermal furniture helped increase air temperature by 6.5 %, compared with that of single occupant and the averaged PPD (Predicted Percentage of Dissatisfied) value around the occupants by maximum 5.4 % for one occupant and 11.5 % for two occupants, respectively. The location of occupant was very sensitive to flow stream path, e. g. the PPD distribution was symmetrical in the spanwise position but became asymmetrical in streamwise position. Further investigation of thermal comfort level using Fanger’s indices due to ventilation rate and thermal load led that desirable indoor environment might be achieved with higher ventilation flow rate (Uinlet > 0.7 m/s) rather than reducing heat generation from the heating sources for more occupants introduced to the room. The results in the thesis summarise some of the important reservations with regard to the CFD capability and reliability for indoor thermal environment and present data would be useful for the built environment thermal engineers in design and optimisation of domestic rooms.

Current work is a thorough investigation on the processing and mechanical properties and the toughening mechanism of nanorubber-modified epoxy and the carbon and glass fibre reinforced composites produced using these matrices. The study is aiming to assess the applicability of these novel nanorubber-modified matrices to advanced industrial applications where fracture toughness is the main concern. In the first section of this research, process optimisation of the nanorubber-modified epoxy was studied. Dispersion techniques of triple milling, high shear mixing and ultrasonic bath were used in order to enable an even and nano-size dispersion of the acrylonitrile-based nanorubbers in the epoxy matrix. Triple milling was chosen as the dispersion technique which enabled an even and nano-scale dispersion of the nanorubber particles in the epoxy resin matrices. Scanning electron microscopy (SEM) images revealed that CNBR-NP could be dispersed evenly in the epoxy matrix using industrial mixing process whereas partial agglomeration was observed in NBR-NP blends. The difference in the dispersion ability of these two nanorubbers in epoxy was related to the difference in van der Waals forces between single nanoparticles, the chemical formula and the polarity of the systems. In the second stage of this study, the effects of nanorubber on the rheological properties, cure characteristics and mechanical properties of epoxy resin were investigated. The dynamic mechanical behaviour of the carbon fibre reinforced polymer composites (CFRP) with the neat and the nanorubber-modified matrices was also studied. Rheological study showed that the NBR-NP blends attained lower viscosity in comparison to CNBR-NP blends and both systems exhibited shear-thinning behaviour. The dynamic mechanical analysis (DMA) data showed that the addition of nanorubber has negligible effect on the glass transition temperature of the epoxy. The effects of the nanorubber on the interlaminar shear strength, fracture toughness and tensile fatigue behaviour of carbon and glass fibre reinforced polymer composites (CFRP, GFRP) was studied. Mechanical properties of tensile strength, apparent shear strength, Mode I and Mode II delamination fracture toughness, impact toughness and tension-tension fatigue were analysed. The results showed that the nano-size dispersion of rubber significantly improved the Mode I delamination fracture toughness (G[sub]IC) of the CFRP by 251% and its Mode II delamination fracture toughness (G[sub]IIC) by 81% with the addition of 20 phr of CNBR¬NP to the resin matrix. For the NBR-NP system, the G[sub]IC and G[sub]IIC delamination fracture toughness of the CFRP were improved by 203% and 83% respectively with the addition of 20 phr of NBR-NP to the matrix;. Scanning electron microscopy (SEM) images of the CFRP fracture surfaces revealed that the toughening was mainly achieved by the de-bonding of nanorubber, crack path deflection and fibre bridging. The Mode I delamination fracture toughnesses (G[sub]IC) of the GFRP with the addition of 20 phr of CNBR-NP and NBR-NP were improved by 190% and by 150% respectively. Similarly, the Mode II delamination fracture toughness (G[sub]IIC) of the GFRP panels was improved by 73% and 67% with the addition of 20 phr of CNBR-NP and NBR-NP respectively. SEM images of the Mode I delamination fracture surface of the GFRP panels proved that the interfacial adhesion between the individual glass bundles and the matrix was improved with the addition of nanorubber. The tensile-fatigue behaviour of the CFRP panels with X CNBR-NP/ R matrices was studied. The normalised test data revealed that the high cycle fatigue life was enhanced by twice with the addition of 15 phr of CNBR-NP in the neat epoxy matrix. SEM images of the fracture surfaces proved that the better. adhesion of nanorubber-modified matrix to the carbon fibres supressed fibre pull-out and contributed towards the enhanced fatigue life of the panels.

Energy plays a major role in the economic prosperity of the Middle Eastern countries. Since the region is the largest oil producer of the world, it is less anticipated that these countries would ever be face with an energy crisis similar to the one experienced by the rest of the world during 1970s. The region was going through a chronic electricity demand supply crises with the demand for electrical energy in the rapidly expanding towns, cities and industries, far exceeding the power being made available. The relatively low electrical tariff also contributed to the increasing power demand due to wastage and uneconomical usage of electrical energy. The power generating companies and the Government authorities in the Middle East encouraged scientists and engineers to engage in ambitious Demand Side Management (DSM) programmes to develop novel ideas and new technologies to improve system efficiencies and to reduce energy consumption specifically in the field of refrigeration and air conditioning. The researcher began analysing the potential and possible applications of cool storage as a tool for Demand Side Management (DSM) in central air conditioning systems in the Middle East in 1991. The coupling of a refrigerated water storage tank or an ice storage tank to an air-cooled chiller plant, operated at night for load shifting, electrical peak demand reduction and energy conservation has been the major interest of investigation. The model project commissioned in 1996 used as a typical example to investigate electrical demand management for an office building in Riyadh, Saudi Arabia. The aim of this research was to develop new modified comfort cooling system coupled with a cool storage or commonly known as Thermal Energy Storage (TES) network. The research was expected to establish certain favouring conditions in relation to technical, economical and environmental criteria to make the TES application a viable option in comfort cooling systems in commercial buildings in the Middle East for electrical demand reduction, load shifting and energy conservation.

Just In Time (JIT) is a Japanese manufacturing philosophy. It involves a set of relative1y innovative manufacturing strategies which are considered different to traditional practices. This research is focused on the development of a flexible JIT modelling system which can be used by small and medium sized manufacturing firms to determine the potential impact of a full scale JIT implementation in their factory. As there are so many potential benefits from JIT manufacturing, many smaller companies may not be able to achieve all of the benefits in one go and may want to focus on selective but tangible benefits in a progressive manner; The proposed system can help the company to achieve a tactical advantage by selecting the appropriate benefits suitable for their specific requirements. During this research, key elements of JIT manufacturing are identified and grouped into three categories, namely (1) Tools and Techniques, (2) Human Resources and (3) Supplier Aspects, so that they can be deployed in any combination according to the company's requirements. The major benefits arising from the implementation ofthese elements are also identified. Using the Pearson Correlation technique and Multiple Linear Regression, a relationship between specific elements of JIT manufacturing and their respective benefits has been established.

The turbocharger is a performance enhancing device which uses the hot exhaust gas mixture from the engine exit to spin the turbine blades for driving the compressor blades to compress the ambient air from the atmosphere. During the operation, the turbine blade surfaces will have severe contaminated deposit accumulations due to the usage of the low-grade diesel fuel for the engine combustion. Hence, this will adversely impact on the turbocharger operating efficiency with some significant performance losses. In this aspect, the development of efficient and cost-effective deposit removal techniques has become one of the urgent tasks for the turbocharger design and manufacture industries. Apparently, an engineering solution to the problem is to apply a built-in “online” water washing system for diesel turbocharger deposits removal. While this method has been used for a while now, the system performance is not entirely satisfactory and further improvements are very demanding. The intention of this study is to review the current know-how industry practice of deposit removal techniques, in particular the “online” water washing technique, in order to understand the underlying mechanisms. The objective is to provide detailed information and flow characteristics for turbocharger designers to improve the system performance. To achieve these targets, a research programme of combining numerical simulation and experimental test has been proposed and carried out on a medium sized diesel turbocharger model to investigate both single-phase gas mixture flow and two-phase gas/liquid flow characteristics. In the latter case, the study is focused on the droplet trajectory, the size distribution and the water droplet coverage area on the blade ring. The experimental tests were based on an in-house test rig at Napier Turbochargers. The measurements were conducted over a wide range of working conditions with and without water washing injections. The test results were used for data analysis and validation of numerical predictions. It was found that in general the water coverage area decreases with the increase of turbocharger loading speed. By using three water injectors evenly distributed in a circumferential direction, maximum ten blades have been washed (i.e. “wetted” blades), while the remaining fourteen blades stayed “dry”. This indicated that more water injectors might be needed to increase the water coverage area on the blade ring. It was also noted that the test rig employed has some limitations of test loading speeds and temperature range, preventing its application to wider operation conditions. The numerical simulations of single-phase gas mixture flow and two-phase gas/liquid flow have been carried out using a commercial computational fluid dynamics (CFD) software ANSYS-CFX with ‘ad hoc’ subroutines of the CFX Command Language (CCL). For a single-phase gas mixture flow, the numerical predicted blade leading-edge temperatures were in good agreement with the experimental measurements with max 1% discrepancies. The results also revealed some influences of three upstream guide vanes on the downstream flow field. For a two-phase flow, the computation has been carried out using the coupled Eulerian/Lagrangian method. Similar to the single-phase flow, simulation results of two-phase flow were generally in good agreement with the experimental observations qualitatively and quantitatively, e.g. the water coverage increases with the decrease of the turbocharger loading speed. For all simulation cases, the water droplet movements in the computational domain have been visualised by the particle trajectory tracking and the 3D iso-surface plotting, etc. A standard conical shaped of water spray cones were clearly seen. Other aspects of the studies were the validation and the assessment of various models adopted in the simulations. The numerical optimisation of the water nozzle configuration was also performed by parametric studies, such as the injector geometry, the injection location and the inclination angle. For a water injector at two inclination angles of 30[sup]o and 90[sup]o against the mainstream flow with different loading speeds, simulation results were in good agreement with the experimental measurements at corresponding test conditions. It was found that for the 90[sup]o inclination angle with the standard nozzle, the number of “wetted” blades was similar to that from the 30[sup]o inclination angle case, but the water coverage area was shifted to the upper half of the blade ring. For the nozzle injection angle at 90[sup]o with a spacer inserted, the numerical predictions have been performed with success and the water coverage has shown some regular patterns as those seen in the standard nozzle simulations. However, surprisingly, this did not entirely agree with the experimental observations, where the water droplet particle distributions on the blade surfaces were randomly distributed without any clear patterns. To understand the underlying cause, some further studies are needed, e.g. the nozzle injection point and the droplet break up model influences. Similar to other numerical simulations, limitations of CFD work are mainly due to the influence of turbulence models and other sub-models used in this study. Further improvement could be done through model refinement study and validation against wider range of test data. In conclusion, the present study has shown that numerical predictions using CFD techniques are generally in good agreement with the experimental measurements in terms of the blade leading-edge temperature distributions and the blade ring water coverage. The flow details such as the water droplet particle trajectory and the size distribution are obtained and they are valuable for the design engineers to improve the current “online” water washing system. Furthermore, the simulation models developed in this study can be used for modelling other conditions that are difficult to perform on the current test rig (mainly due to the safety constraints).

The objective of the present work is to develop mathematical/finite element based optimization techniques for fibre reinforced polymer (FRP) laminated composite structures subjected to buckling. Many issues arise when a laminated FRP composite structure subjected to compressive load and ultimately fail under buckling. Issues such as understanding FRP composite materials, buckling and post-buckling behaviour of the structure, delamination and detection of the crack front need attention. Hence, in the present research works were carried out in each of these areas. Various experimental studies were carried out to study material characterisation, the delamination fracture toughness in mode I, mode II and mixed-mode l/ll using DCB, ENF and MMB tests and buckling of FRP composite plates. From these series of test GIC, GIIC and fracture envelope under different mode mixity ratio were determined. Also the buckling tests of the plates with optimum and non-optimum stacking sequence were performed to verify the optimisation results. The effect of damage on buckling load was studied by tests on buckling of plates with pre-existing centrally located delamination patch at the plate mid- plane and on plate with a hole at the centre of the plate to investigate the effect of cut-out and damage on buckling load. Finally, IR thermography and CT-Scan non-destructive tests (NDT) were used for plates with pre-existing centrally located delamination patch to study the direction and the extent of delamination crack propagation after the buckling tests. In the case of plates with pre-existing centrally located delamination patch with diameter less than 32mm, the critical buckling load has not changed. But when the delamination patch diameter reached to 48mm (at around 60% of plate width), there was significant reduction in the critical buckling load. in the case for plate with cut-out a noticeable reduction on the critical buckling load was observed when the diameter of the hole was more than 25% of the plate width. IR thermography and CT-Scan images analysis of the plates after buckling tests showed that in plates with pre-existing centrally located delamination patch with a diameter of D=16 mm, the plate failure occurs near the loading edge. In the case of plates with delamination patch of D=32mm, some plates failed near the loading edge and in some plates crack propagated along the i45° fibre direction around delamination patch. However, for plates with delamination patch with diameter of D=48mm, in all samples the delaminated area propagated along the fibre direction around the delaminated area and no failure observed near the loading edge. Inherent to the use of FRP composite materials is the inclusion of ply angles and stacking sequence as design variables. These design variables are discrete in nature. The optimization of these models is typically difficult due to their combinatorial nature and potential existence of multiple local minima in the search space. In this research bottom-up enumeration search optimisation approach was developed for optimum design of stacking sequence of laminated composite structure for maximum critical buckling load above the required target load using MATLAB software. The optimised results were verified by buckling experiments and FE simulations. The developed programme is flexible to use for other loading condition. For the case of uniaxial compressive loading with preselected target buckling load, the optimum number of layers and orientation for 0/90 biaxial fabrics and unidirectional plies were determined. The percentage of difference between analytical buckling load and FEA eigen solution with experiments are about -13.1% and -3.2%, respectively. Depending on the properties and arrangement of the skin and stiffener, different buckling modes and failure loads can occur in a stiffened plate. For shape optimisation of blade- stiffened plate subjected to buckling, Sequential Quadratic Programming (SQP), Genetic Algorithms (GA) and Simulated Annealing (SA) techniques were used in MATLAB optimisation programme in conjunction with ANSYS finite element software. The developed techniques are tested for minimum weight of a blade-stiffened plated with predefined stacking sequence of stiffener and the plate where the geometry parameters were design variables. In this work, the size of the stiffener height and the distance between the stiffener for a required target buckling load and optimum weight were determined.

Liquefied Natural Gas (LNG) is currently playing an important role in the world energy markets. This is evidenced by growing demand and increased construction of LNG facilities across Europe and the United States. In the event of spill from any of the facilities handling LNG such as during liquefaction, transportation or regasification, flammable vapour is formed which disperses through the atmosphere constituting fire and explosion hazards. To ensure public safety in the midst of growing LNG demand and facilities construction, industries are usually mandated to demonstrate that public safety will not be undermined by potential spill from their facilities. One method that is currently being used to demonstrate compliance is through LNG vapour dispersion modelling using Computational Fluid Dynamics (CFD). CFD modelling of dispersion phenomena is a challenging task that requires rigorous methodology to account for the underpinning physical processes. The modelling process comprises of two steps: source term quantification and vapour dispersion modelling. Source term quantification involves the physical description of spill rate, pool spreading and evaporation. Vapour dispersion utilizes the result of source term quantification in order to predict the turbulent entrainment and dilution process with the ambient wind. Existing models employ simplifying assumptions that circumvents explicit source term modelling. The spilled liquid is assumed to fill the entire substrate immediately at which time the spill rate becomes equal to evaporation rate. Following this assumption, a fixed inlet patch area and evaporation rate is applied at the gas inlet boundary. This approach fails to incorporate the transient pool development and subsequent evaporation into the dispersion modelling process. The primary aim of this dissertation is to develop an efficient integrated pool spreading, evaporation and dispersion (I-PSED) model code for LNG vapour dispersion simulation. This represents a significant shift from the traditional method since the new methodology combines the spilling process, spreading on substrate and transient evaporation into a unified model. For the spilling process, the well- known orifice model has been adopted to predict the spill rate taking into account the decreasing head. A mass balance approach is adopted in conjunction with a well¬established similarity model for spreading calculation. Heat transfer to the spreading pool is incorporated based on film boiling correlation. The spreading model was then coupled to an atmospheric dispersion model within OpenFOAM framework through the implementation of a new boundary condition in which the gas inlet patch area changes based on the instantaneous pool radius. The developed integrated code (I-PSED) is validated against data from the Coyote Series LNG Spill experiments as well as against Shell's Maplin Sand LNG spill experiments. Predictions of concentration obtained using the proposed model and those obtained using conventional approach are compared against experimental data at specific sensor locations. Also, arc-wise comparisons are carried out. Predicted results show good agreement with experimental data and clearly put the newly developed model ahead of the conventional approach for CFD simulation of LNG vapour dispersion. With the newly developed approach, the cloud arrival time and average concentrations at most sensor locations were better predicted. The effect of the turbulent production due to density stratification (buoyancy) created by the release of cryogen is investigated. Experience gathered shows that incorporation of a production term due to buoyancy in the turbulence model improves predictions under unstable atmospheric condition, otherwise the concentration field would be grossly over-predicted.

In this project it was planned to synthesise and investigate the physical, chemical and electrical properties of the "polyquinoxaline" family of materials. The compounds synthesised and studied included 5,14-dihydro-5, 7,12, 14-tetraazapentacene(L5H[sub]2), dibutyldihydro-5, 7,12, 14-tetraazapentacene (L5Bu[sub]2H[sub]2), 7, 16-dihydro-5, 7,9,14,16,18-hexaazaheptacene(L7H[sub]2), 7,20-dihydro-5, 7, 9, 11, 16, 18, 20, 22-octaazanonacene (L9H[sub]2), dibutyldihydro-5, 7, 9, 11, 16, 18, 20, 22- octaazanonacene (L9Bu[sub]2H[sub]2), "Polyquinoxaline"(poly[ 1, 6-dihydropyrazino(2, 3-g)-quinoxaline-2, 3,8-triyl-7(2H)-ylidene-7,8-dimethylidene) and the dibutyl-substituted (poly[ 1, 6-dihydropyrazino(2,3- g)-quinoxaline-2,3,8-triyl-7(2H)-ylidene-7,8-dimethylidene). Some alkyl-substituted oligomers were also made, so as to increase their solubility in organic solvents. Both liquid phase and solid phase synthesis have been used in preparing these compounds, the latter being done in an attempt to produce the compounds in their purest form. In the case of L7H[sub]2, this method gave the first successful synthesis of the compound. A number of techniques, such as FTIR, solid-state NMR and Visible / Ultraviolet spectroscopy have been used in characterising both the synthesised compounds and the first in the "quinoxaline" series of compounds phenazine (L3), which is commercially available. For solutions of the oligomers in concentrated sulphuric acid, the HOMO-LUMO absorption bands in the UV-visible decreased monotonically with the number of rings. The electrochromic properties of vacuum evaporated thin films of dihydrotetraazapentacene (L5H[sub]2) and dihydrohexaazaheptacene (L7H[sub]2) have been investigated using cyclic voltammetry. These investigations suggest that L7H[sub]2 thin films exhibit similar intermediate redox states to L5H[sub]2 films. Two-point electrical conductivity measurements have been carried out on pressed powder pellets of doped and undoped oligomers, substituted oligomers and ladder polymers. The electrical conductivities showed marked increases of five to six orders of magnitude as a result of doping the materials with hydrogen chloride vapour. The final major part of the project was the first fabrication of metal-semiconductor Schottky diode devices based on vacuum-evaporated thin films of dihydrotetraazapentacene (L5H[sub]2). Schottky diode devices on L5H[sub]2 films were successfully made using a range of metal contacts (Sn, Cu. AI, Pb, Au and Ag). Electrical measurements on various metal-doped L5H[sub]2 films gave I-V characteristics indicative of a Schottky barrier formed at a metal/n-type semiconductor interface. These electrical device measurements were mathematically modelled to determine the magnitude of the Schottky barriers at the various metal-semiconductor interfaces. This information and the electrochromic redox measurements on L5H[sub]2 thin films have helped to characterise the charge-transfer processes in these oligomer thin films.

This thesis addresses the behaviour of glass in fire condition. The behaviour of glazing could influence the growth of fires. Radiation is often the most significant heat transfer mechanism and its modelling is critical to an accurate prediction of temperature distribution in the glass and the time to breakage. A literature review on the theoretical modelling and experimental aspects of glazing systems exposed to fire are presented. Theoretical issues of glazing modelling in fire conditions were identified. To address the limitations of existing approaches, a more robust computer tool, referred to as Fire Dynamics Simulator - One Dimensional & Three Dimensional Spectral Discrete Ordinate Method (FDS-1D & 3D-SDOM) was developed in this thesis. The new computer tool is comprised of (i) a CFD part for the fire dynamics and fluid flow simulation, (ii) a spectral Discrete Ordinates radiation model for radiative source term calculations in the glass, and (iii) a FEA part for the 3D thermal conduction thermal stress, thermal strain and the probability of failure in glass material. For verification purposes, the model is applied to some typical fires/glazing scenarios from the literature. Good agreements are found between predictions and experimental data. The study also investigates the effects of the glass thickness, thermal conductivity and emissivity on the glass temperature.