A sustainability analysis was performed on the UK car fleet in 1995 and 2005, which showed that the sustainability of the car fleet improved by 13% over the time period. The Process Analysis Method was applied to generate a reliable, consistent, and sufficient indicator set describing the sustainability impact of a transport system. As well as identifying conventional impacts, this analysis identified that the quality of the mobility produced has an important impact on sustainability. Quality affects how well mobility meets human needs, but also influences user choices, which drive system change. It is suggested that the indicator set that was produced should form the basis for future sustainability assessments. A study was carried out on the UK car fleet in 1995 and 2005 to test the indicator set and to investigate changes in environmental, human/social and economic sustainability over the period. Distance travelled increased, driven by a 28% increase in fleet size, which counteracted increases in fuel efficiency. Weight also increased, driven by increasing vehicle size, and additional safety and comfort-related features, increasing embodied energy and emissions. However, direct emissions of non- CO2 pollutants reduced due to increasingly stringent regulation, as did waste to landfill. CO2 emissions increased by 11% overall. The reduction in emissions had a positive impact on health, with emission related mortality reducing by 27%. Casualties from collisions involving cars reduced by 13%. Road accidents were found to represent an impact on mortality three times greater than emissions. The indicators of service quality showed a drop in average speed and reliability (from both the network and vehicle perspectives) but an increase in comfort and vehicle safety. The increase in fleet size and new registrations drove growth in the retail and maintenance sector, which saw growth of 25% in gross value added. The opposite happened to the manufacturing sector, which shrank by 26%, due to stagnant domestic production and an increasingly competitive market affecting profit margins. An indicator aggregation was performed to summarise changes in the sustainability of car-based mobility. The indicators were normalised to a percentage change, and weighted according to their monetary value.

Concentration polarisation and fouling reduce performance as well as increase costs. In order to mitigate these effects, understanding the cause and effects of these phenomena is crucial. It has been hypothesized, and to a certain extent shown, that amelioration of fouling can be achieved through the use of time varying shear for example use of air-sparging or sharp changes in crossflow velocity. Nevertheless the effect of shear on membrane fouling, in particular its effect on the foulant deposition and the transmission of small molecules in microfiltration, is not well understood. The goal of this project was to achieve an understanding of various foulant be- haviour. The work was divided into two parts. Firstly, the observations of fouling by freshwater algae, Chlorella Sorokiniana, were carried out at Nanyang Technolo- gical University, Singapore. Observations using macroscopic parameters were ex- amined with an optical non-invasive observation technique called Direct Observa- tion Through Membrane (DOTM). The result yielded a novel relationship between operating flux, crossflow velocity and transmission of extracellular polysaccharide. Interestingly shear was shown to have positive as well as negative effects on fouling of microfiltration membrane. The analysis of permeate has clearly shown that a maximisation of shear rate was not ideal. The second part was concerned with observations of the effect of shear patterns on membrane fouling using newly fabricated special membrane filtration cell, Direct Shear Stress Test Cell (DSSTC), designed to fit an Anton Paar rheometer and op- erate at constant flux. Unlike the-constant-shear-filtration cells, one could impose a very wide variety of shear regimes including intermittent sharp changes of direction and sinusoidal oscillations in the DSSTC. The effect of shear patterns on transmis- sion and fouling of a model polysaccharide (Dextran Blue) through microfiltration membranes was carried out at various conditions. Again, the results showed that the maximisation of shear rate was not ideal. The effect of shear patterns and EPS on fouling by yeast suspension was also studied using the DSSTC. The benefit of oscillatory shear is foulant dependent. For example, square wave oscillatory shear led to lower relative fouling for yeast EPS, but it resulted in higher relative fouling for unwashed yeast.

Combustion monitoring in internal combustion engine or burners is a difficult task due to the harsh environment for any sensor, therefore optical diagnostics are very attractive for these types of application. Chemiluminescence measurement is one of the most common and most promising ways of implementing optical diagnostics in combustion monitoring applications because the measured signal, emitted naturally with combustion, has potential to be an indirect measure of combustion relevant parameters, such as the equivalence ratio and heat release rate. In hydrocarbon combustion, the most common chemiluminescence emitters are OH*, CH*, C₂* and CO₂*. This thesis focuses on the measurement of OH* and CH* chemiluminescence, whose sensitivities are affected by temperature, pressure, equivalence ratio and stretch rate. To measure OH* and CH* chemiluminescence, an existing constant volume combustion vessel has been refurbished, along with the sub-systems for fuel delivery, ignition, LabView control, data acquisition, and optical detection using a pair of photo-multiplier tubes (PMTs), interference filters and a series of apertures. Modelling accurately the optical setup is essential for the CH* and OH* chemiluminescence measurements in the combustion bomb. To achieve this goal, a narrow field of view system has been selected as it enables the elimination of photons scattered from the internal surfaces. A calibration of the PMTs converts the measurements into the absolute OH* and CH* chemiluminescence in terms of watt. Measurements from a combustion bomb are versatile and accurate since it determines the OH* and CH* chemiluminescence as a function of temperature and pressure from a single experiment. The calculation of the normalised OH* and CH* chemiluminescence (against mass burned rate) was based on a multi-zone combustion model and measured pressure record from the vessel. NIICS (Normalised Intensity Integrated Calculation System) has been created to fetch data from the multi-zone model, the optical model, and experimental measurements, to match them up by interpolation and to normalise the OH* and CH* chemiluminescence. NIICS also allows the user to select data uncorrupted by the noise and heat transfer. The chosen data (in this case, CH*/OH* chemiluminescence ratio) have been fitted using a multi-variate fitting and correlation analysis. This formulation can be used to indicate the local equivalence ratio from premixed methane / air and iso-octane / air flames over the local pressure range 0.5 – 20 bar, the unburned gas temperature range 450 – 600 K, and equivalence ratio range 0.8 – 1.1. The chemical-kinetic mechanisms of the absolute OH* and CH* chemiluminescence have been investigated by studying the influence of the equivalence ratio, unburned gas temperature, and local pressure. It should be pointed out that two confounding observations occur, i.e. a discontinuity in the chemiluminescence along the isentropes, and chemiluminescence continuing after the end of combustion. This led to the further spectroscopic analysis. This study concluded with spectroscopic measurements using an Ocean Optics spectrometer and a Princeton ICCD spectrometer. It was found that the broadband CO₂* is responsible for the two disconcerting observations. In addition, CH* chemiluminescence has been shown to be very faint from premixed laminar methane / air flames; hence the CH*/OH* formula in essence quantifies the CO₂*/OH* ratio as a function of pressure, temperature, and equivalence ratio. The ‘CH* chemiluminescence’ can characterise the background CO₂*, so as to provide a practical way to probe the feasibility of absolute OH* as an indicator of combustion relevant parameters in the future.

Membrane filtration is used in a variety of industries, including water treatment and the food industry. Membrane systems include microfiltration and reverse osmosis processes. Membranes used in reverse osmosis are nonporous or pores at 0.2-2 A. This work will focus on mechanical microfiltration. These filtration systems suffer from an accumulation of the rejected material near the membrane surface. This causes additional resistance to the flow through the membrane (flux), resulting in a decline in the performance of the system. Sparging gas bubbles into the mixture has been shown to improve performance. The flow field promotes the transport of material away from the membrane surface and into the bulk. The goal is to predict the sparging that will achieve the maximum flux. Existing flux prediction models often assume steady shear at the membrane surface but in bubbling regimes the shear stresses are unsteady. In this thesis a model is developed to calculate the flux based not solely on shear but on the behaviour and resistance of suspended particles in a gas-liquid flow field. The bubble shape and flow field is calculated using computation fluid dynamics (CFD). The flow around a bubble in gap between two parallel flat sheet membranes is investigated. The calculated bubble shape correlates well with the results seen in experiments. The bubble rise velocity with respect to gap width is shown to transition between that expected in the literature for extended flow for large gap widths and that for a two dimensional case for smaller gap widths. The transitional region however, does not behave as may be expected. The rise velocity does not monotonically decrease as the gap width is reduced. The particle concentration is found by the solution of the convection-diffusion equation, where the convection velocity terms are given by the results of the CFD calculation. The permeate flux is then calculated using a resistance model giving the enhancement due to the bubble. The model is also applied to single phase crossflow. As the shear stresses are steady in this single-phase flow regime, established membrane shear linked mass-transfer coefficient methods can be employed. Good agreement is found between the model and theory. The flux results obtained when the model is applied to the flow around the bubble show a peak in performance with respect to the gap between the membranes for a given bubble volume. The optimal flux enhancement is found to correlate well with the bubble size compared to the flow area. The results show a bubble width of around 60% of the flow width provides the best flux performance.

Energy models are optimisation tools which aid in the formulation of energy policies. Built on mathematics, the strength of these models lie in their ability to process numerical data which in turn allows for the generation of an electricity generation mix that incorporates economic and the environmental aspects. Nevertheless, a comprehensive formulation of an electricity generation mix should include aspects associated with politics and society, an evaluation of which requires the consideration of non-numerical qualitative information. Unfortunately, the use of energy models for optimisation coupled with the evaluation of information other than numerical data is a complicated task. Two prerequisites must be fulfilled for energy models to consider political and societal aspects. First, the information associated with politics and society in the context of energy policies must be identified and defined. Second, a software tool which automatically converts both quantitative and qualitative data into mathematical expressions for optimisation is required. We propose a software framework which uses a semantic representation based on ontologies. Our semantic representation contains both qualitative and quantitative data. The semantic representation is integrated into an Optimisation Modelling System which outputs a model consisting of a set of mathematical expressions. The system uses ontologies, engineering models, logic inference and linear programming. To demonstrate our framework, a Prototype Energy Modelling System which accepts energy policy goals and targets as inputs and outputs an optimised electricity generation mix has been developed. To validate the capabilities of our prototype, a case study has been conducted. This thesis discusses the framework, prototype and case study.

Sous le vocable de liants calciques, on regroupe différents composés du calcium : sulfate, aluminates et silicates de calcium. Ils ont pour caractéristique de donner, à l'issue de leur réaction avec l'eau, des masses solides dont les propriétés mécaniques arrivent à surpasser celles des formations minérales. L'obtention de telles résistances mécaniques, les prédispose à être utilisés comme matériaux de construction (différents plâtres et ciments) et leur confère une utilité pratique faisant l'objet d'une importante activité industrielle. Les réactions d'hydratation associées à un phénomène de "prise" ne se produisent qu'avec un nombre limité de substances et se distinguent en cela de l'ensemble des réactions : Anhydrite + eau → Hydrate + Q calories. Dans le but d'améliorer les qualités des matériaux de construction et de se rendre maître des phénomènes physico-chimiques complexes par lesquels ils se forment, les travaux de recherche s'attachent à définir la spécificité du mécanisme d'hydratation des liants calciques.

Microneedle is a promising technique for delivering high molecular weight drugs across skin. The microneedles can offer a number of benefits over other drug delivery methods. For example, the drugs only diffuse over a short distance before reaching the blood circulation which enhances the absorption of drugs by the tissue. However, the drug transport behaviour in skin is affected by a complex interplay of many parameters (e.g., microneedle geometries, permeability across skin, etc). In this thesis, many aspects of the microneedle field were examined. A mathematical model for drug transport from microneedle systems into skin was developed. Issues such as microneedle penetration, surface area of the microneedle arrays, etc. were investigated. This work helped us to focus into optimizing the design of microneedles by developing an in-house algorithm to enhance the performance of transdermal drug delivery using microneedles. Following the development of this algorithm, the influence of skin thickness with its classification (i.e., age group, race, etc.) on drug permeability across skin was studied. Attention was then given to determine the effective permeability (Peff) and the effective skin thickness (Heff) for various solid microneedle models. The outcome of this research allowed us to study the influence of microneedle dimensions on the drug concentration in blood (Cb). Furthermore, the 'pattern' (shape) of the microneedles array (i.e., square or rectangular) and the 'distribution' (arrangement) of the microneedles inside an array (i.e., triangular or diamond) were investigated to identify the optimum microneedle models. Finally, the effect of skin metabolism on both the patch (without microneedles) and the microneedle arrays on drug intake were examined.

With the depletion of hydrocarbon fuels, the hydrogen-hydrocarbon combustion system provides a good solution for the transition period from a hydrocarbon-based energy sys- tem to a hydrogen-based energy system because of its desirable combustion characteristics and the low level of modification to current combustion systems. Though extensive re- search has been carried out to investigate the combustion process of hydrogen-hydrocarbon fuels, no experiments have been reported to study the Particulate Matter (PM) formations in hydrogen-hydrocarbon combustion systems. To measure the PM concentrations in a laminar diffusion flame, a new optical diagnostic technique, called Cone-Beam Tomographic Three Colour Spectrometry (CBT-TCS) has been developed to measure the spatially distributed temperature, soot diameter and soot volume fraction. This technique is based on the principle of three colour pyrometry, but uses a more rigorous light scattering model to calculate the soot diameter and soot volume fraction. The cone beam tomography technique has also been used to reconstruct the 3D property fields from the 2D flame images. The detailed theoretical principles, the exper- imental setup, the optical considerations, the reconstruction algorithm and the sensitivity analysis are all introduced. The CBT-TCS technique has been successfully applied to several laminar diffusion flames to study the PM formation. The temperature and soot volume fracction profiles measured by CBT-TCS for a ethylene laminar diffusion flame are consistent with the data reported by Snelling et al. [77]. The helium-ethylene-air flame tests show that adding helium reduces the PM formation (due to the dilution effect). The hydrogen-ethylene-air flame tests show that adding hydrogen is more effective in reducing the PM formation due to the combined effect of dilution and direct chemical reaction. A PM sampling system has also been de- veloped to verify the PM size distributions measured by CBT-TCS. The comparison results show that the CBT-TCS tends to overestimate the particle size. Several optical engine experiments have also been undertaken to investigate the effect of adding hydrogen on the PM emissions from a Gasoline Direct Injection (GDI) engine. The hydrogen-ethylene engine tests show that adding hydrogen can reduce the PM emissions without sacrificing the power output. The hydrogen-base fuel (65% isooctane and 35% toluene) tests show that adding hydrogen can improve the combustion stability and reduce the PM emissions, especially at low load. Adding 5% stoichiometric of hydrogen can reduce the total PM number concentration by 90% for a stoichiometric mixture and 97% for richer mixture at low load. At high load, adding 10% stoichiometric of hydrogen can also reduce the total PM number concentration by 85% for richer mixture but has little effect upon the stoichiometric mixture.

L'exploitation de gisements pétroliers off shore doit souvent faire face à des problèmes de colmatage de conduites, notamment dus à la cristallisation d'hydrates de gaz. Actuellement, les opérateurs ont recours à des additifs antigels, dont l'efficacité est limitée par des conditions d'exploitation et des normes anti-pollution de plus en plus sévères. Aussi les recherches s'orientent-elles vers une nouvelle classe d'inhibiteurs dits à faible dose. Afin de comprendre l'influence de tels additifs, nous avons réalisé un réacteur haute pression muni d'un dispositif d'injection de liquide et d'un capteur turbidimétrique <i>in situ</i>. L'accès à la granulométrie de la suspension aux premiers stades de la cristallisation et à la consommation de gaz permet de caractériser la cinétique de formation de l'hydrate de méthane. Nous avons développé un protocole opératoire original qui autorise une maîtrise accrue de la germination des cristaux, grâce à un ensemencement initial de la solution. Le temps de latence devient alors un paramètre représentatif de l'efficacité des inhibiteurs. Nous avons alors évalué l'influence des conditions de pression et d'agitation sur l'évolution de la population de cristaux en l'absence d'additif. Puis nous avons déterminé l'effet inhibiteur d'un additif cinétique modèle, la polyvinylpyrrolidone (PVP). Mis en solution avant la cristallisation, il allonge la période de latence, diminue la vitesse de consommation du gaz et ralentit la création de nouvelles particules durant plusieurs heures. Par contre, lorsque ce polymère est injecté dans le milieu en cours de formation, il n'affecte plus la cinétique de la réaction. Nous donnons enfin les bases d'un modèle relevant des processus élémentaires de cristallisation : germination, croissance et agglomération des particules. Confrontée aux données expérimentales, une étude paramétrique nous a permis d'émettre des hypothèses quant à l'effet des inhibiteurs cinétiques sur la formation des hydrates de gaz.

Le bois est un bio polymère qui se distingue des autres matériaux industriels (polymères, métaux) par son origine végétale. Dérive d'un tissu cellulaire, il est hygroscopique, anisotrope, instable dimensionnellement et vulnérable aux attaques biologiques (insectes et champignons). Le procédé de rétification du bois consiste en une pyrolyse ménagée (entre 180 et 250°C) sous atmosphère contrôlée et réduit de façon notable l'hygroscopie, l'instabilité dimensionnelle et la biodégradabilité du matériau traité. Cette étude a mis en évidence des différences de sensibilité thermique entre les feuillus et les résineux. Ces derniers peuvent présenter des taux de résines plus ou moins importants qui influent sur le comportement du matériau au cours de la rétification. Les départs gazeux observes sont attribués à une destruction importante des hemicelluloses et une modification de la lignine. Le bois traité thermiquement est plus hydrophobe que le matériau de départ en raison d'une destruction de groupes hydroxyles des hemicelluloses. La présence d'acide acétique, issu de la dégradation des hemicelluloses à haute température, permet de catalyser les réactions de condensation de la lignine, mais pourrait également contribuer à la dégradation mécanique du matériau. Une étude menée sur le matériau massif a démontré que la structure cristalline de la cellulose n'est pratiquement pas affectée par le traitement thermique. L'augmentation de la résistance aux attaques fongiques semble être due à des réactions de condensation de la lignine. La quantité de composés extractibles (essentiellement des phénols) augmente suite au traitement thermique. Le paramètre fondamental du procédé de rétification est la température de traitement du matériau. Les analyses de la structure chimique du bois, avant et après traitement par spectrométrie drift, mettent en évidence un seuil pour une température de rétification de 240°C.