This thesis takes an interdisciplinary approach to the problem of the aleatory uncertainty manifest in the design of engineering structures that are subject to random loading, with specific application to continuous gust loading on aircraft and wave loading on offshore structures. The main focus is on aircraft gust loading because this is the area in which more significant progress is made. A review of the literature on gust loading is carried out to evaluate the sufficiency of existing methods and the possibility of a unified certification model is discussed. In order to obtain reliable probabilistic design loads using conventional stochastic simulation techniques, a large number of simulations are required to derive probability distributions that have adequately low sampling variability in the area of interest. A novel method, called the Efficient Threshold Upcrossing method, is developed that reduces the required number of simulations by at least 2 orders of magnitude. The method is initially developed for the efficient derivation of short-term offshore structural response statistics and is subsequently applied to the modelling of aircraft response to continuous turbulence. The ETU method was successfully extended to take into account long-term statistics of nonlinear aircraft response and it was shown that reliable design exceedance curves can be obtained by as little as 4\% of the computational cost of the conventional method. The current methods for the computation of design loads for nonlinear aircraft are limited to discrete, `1~-~cosine' gust encounters as the continuous turbulence models are only applicable to linear aircraft response. However, the most significant outcome of this thesis is that this is no longer the case, because the ETU method provides a way to calculate nonlinear response statistics in the time domain at a significantly lower computational cost. Mathematical models of a simple offshore structure, and both linear and nonlinear aircraft, are developed and a more robust technique is introduced for simulating patches of continuous turbulence. These models, which have the ability to generate random inputs, are used to derive response probability distributions for each of the test structures. The results obtained by applying the new approaches to these data sets show that they offer a marked improvement in performance.

The exploitation of small horizontal axis wind turbines provides a clean, prospective and viable option for energy supply. Although great progress has been achieved in the wind energy sector, there is still potential space to reduce the cost and improve the performance of small wind turbines. An enhanced understanding of how small wind turbines interact with the wind turns out to be essential. This work investigates the aerodynamic design and analysis of small horizontal axis wind turbine blades via the blade element momentum (BEM) based approach and the computational fluid dynamics (CFD) based approach. From this research, it is possible to draw a series of detailed guidelines on small wind turbine blade design and analysis. The research also provides a platform for further comprehensive study using these two approaches. The wake induction corrections and stall corrections of the BEM method were examined through a case study of the NREL/NASA Phase VI wind turbine. A hybrid stall correction model was proposed to analyse wind turbine power performance. The proposed model shows improvement in power prediction for the validation case, compared with the existing stall correction models. The effects of the key rotor parameters of a small wind turbine as well as the blade chord and twist angle distributions on power performance were investigated through two typical wind turbines, i.e. a fixed-pitch variable-speed (FPVS) wind turbine and a fixed-pitch fixed-speed (FPFS) wind turbine. An engineering blade design and analysis code was developed in MATLAB to accommodate aerodynamic design and analysis of the blades. The linearisation for radial profiles of blade chord and twist angle for the FPFS wind turbine blade design was discussed. Results show that, the proposed linearisation approach leads to reduced manufacturing cost and higher annual energy production (AEP), with minimal effects on the low wind speed performance. Comparative studies of mesh and turbulence models in 2D and 3D CFD modelling were conducted. The CFD predicted lift and drag coefficients of the airfoil S809 were compared with wind tunnel test data and the 3D CFD modelling method of the NREL/NASA Phase VI wind turbine were validated against measurements. Airfoil aerodynamic characterisation and wind turbine power performance as well as 3D flow details were studied. The detailed flow characteristics from the CFD modelling are quantitatively comparable to the measurements, such as blade surface pressure distribution and integrated forces and moments. It is confirmed that the CFD approach is able to provide a more detailed qualitative and quantitative analysis for wind turbine airfoils and rotors. With more advanced turbulence model and more powerful computing capability, it is prospective to improve the BEM method considering 3D flow effects.

Thesis advisor: Ziqiang Wang / One of the most unconventional electronic states in high transition temperature cuprate superconductors is the pseudogap state. In the temperature versus doping phase diagram, the pseudogap state straddles across the antiferromagnetic (AF) state near half filling and the superconducting (SC) dome on the hole doped side above the transition temperature Tc. The relationship between the pseudogap state and these two well known states - the AF state and the SC state is believed to be very important for understanding superconductivity and the emergent quantum electronic matter in doped Mott insulators. The pseudogap is characterized by the emergence of a soft gap in the single-particle excitation spectrum in the normal state in the temperature range between Tc and a characteristic temperature T*, i.e. Tc < T < T*. The most puzzling feature of the pseudogap is the nodal-antinodal dichotomy. Observed by ARPES in momentum space, the Fermi surface is gapped out in the antinodal region leaving a Fermi arc of gapless excitations near the nodes. Whether the pseudogap is an incoherent superconducting gap (onegap scenario) or it is a different gap governed by other mechanisms, other than superconductivity, (two-gap scenario) is still under debate. In this thesis I study the particle-particle channel and the particle-hole channel of the valence bond fluctuations away from half filling. Based on a strong-coupling analysis of the t-J model, I argue that the superexchange interaction J induced incommensurate bond centered density wave order is the driving mechanism for the pseudogap state. Low energy density of states (DOS) are eliminated by multiple incommensurate scatterings in the antinodal region at the Fermi level. I show that the interplay between the incommensurate bond centered d-wave density wave instability and the intrinsic electronic inhomogeneity in real cuprate materials is responsible for the observed pseudogap phenomena. Utilizing the spatially unrestricted Gutzwiller approximation, I show that the off-stoichiometric doping induced electrostatic disorder pins the low-energy d-wave bond density fluctuations, resulting in a VBG phase. The antinodal Fermi surface (FS) sections are gapped out, giving rise to a genuine normal state Fermi arc. The length of the Fermi arc shrinks with underdoping below the temperature T* determined by thermal filling of the antinodal pseudogap. Below Tc, the d-wave superconducting gap due to singlet pairing coexists and competes with the VBG pseudogap. The spatial, momentum, temperature and doping dependence of these two gaps are consistent with recent ARPES and STM observations in underdoped and chemically substituted cuprates. The temperature versus doping phase diagram captures the salient properties of the pseudogap phenomena and provides theoretical support for the two-gap scenario. In addition to resolving the complexities of the quantum electronic states in hole-doped cuprates, my unified theory elucidates the important role of the interplay between the strong electronic correlation and the intrinsic electronic disorder in doped transition metal oxides. / Thesis (PhD) — Boston College, 2011. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

A radiomarcação de biomoléculas específicas com o tecnécio-99m 99mTc utilizando agentes quelantes bifuncionais é um campo em crescimento na Medicina Nuclear. Em especial, a classe de peptídeos regulatórios, como a Neurotensina, participa de processos fisiológicos essenciais no organismo, como o crescimento tumoral. O objetivo do presente trabalho foi o estudo comparativo da influência dos agentes quelantes bifuncionais 6-hidrazinonicotinamida (HYNIC) e S-acetil-mercaptoacetiltriglicina (MAG3), no comportamento in vitro e in vivo do análogo duplamente estabilizado da Neurotensina(8-13) radiomarcado com 99mTc, em células tumorais de mama da linhagem MDA-MB-231. Um elevado rendimento radioquímico (> 97%) e estabilidade frente aos agentes transquelantes foi observado para ambos análogos radiomarcados. Foram também obtidos comportamentos similares in vitro, no que diz respeito à porcentagem de ligação às proteinas plasmáticas (aproximadamente 22%), estabilidade metabólica, ligação aos receptores celulares (intervalo nM) e taxas de internalização/externalização para ambos radiocomplexos. A maior lipofilicidade encontrada para o análogo radiomarcado via MAG3 refletiu nas principais diferenças nos estudos de biodistribuição. A degradação do análogo radiomarcado via HYNIC nos estudos de estabilidade metabólica in vivo aos 90 min levou a menor retenção tumoral (0,44±0,02% DI/g), e consequentemente, às menores razões tumor/órgãos não-alvos (< 5%). Embora a superioridade do traçador marcado via MAG3 tenha sido comprovada no presente estudo, um redesenho estrutural objetivando contornar a alta captação no trato gastrointestinal deve ser realizada a fim de que sua potencial aplicabilidade não seja comprometida. / The radiolabeling of receptor specific biomolecules with 99mTc using bifunctional chelator agents represents a growing field in Nuclear Medicine, specially, regarding regulatory peptides, such as Neurotensin, which are important in several essential physiological functions, particularly in tumor growth. The aim of the study was the comparative radiolabeling evaluation of the double-stabilized NT(8-13) analog with 99mTc, via the bifunctional chelating agents 6- hydrazinonicotinamide (HYNIC) and S-acetyl-mercaptoacetyltriglycine (MAG3) in MDA-MB-231 breast cancer cell line. High radiochemical yields (> 97%) and stability toward transchelant agents was observed for both radiolabeled analogs. Also, comparable in vitro behaviour regarding the percentage of plasma protein binding (nearby 22%), metabolic stability, receptor binding affinity (nM range), and internalization/externalization rates were obtained. The greater lipophilicity found for the analog radiolabeled via MAG3, reflected in the major differences in biodistribution studies. The in vivo metabolic stability studies suggested that the degradation observed in the later time point (90 min) for the conjugate radiolabeled via HYNIC, leads not only to lower tumor uptake accumulation (0,44±0,02% ID/g), but also to lower tumor-to-non-tumor ratios (< 5%). Although the superiority of the tracer radiolabeled via MAG3 had been confirmed in the present study, a strucutural re-design aiming the reduction of the high gastrointestinal uptake must be done in order to guarantee the potential applicability of MAG3-radiocomplex.

Thesis advisor: Vidya Madhavan / <p>It has been more than two decades since the first high temperature superconductor was discovered. In this time there has been tremendous progress in understanding these materials both theoretically and experimentally. Some important questions however remain to be answered; one of them is the temperature dependence of the superconducting gap which is in turn tied to question of the origin of the pseudogap and its connection with superconductivity.</p> <p> In this thesis, we present detailed Scanning Tunneling Microscopy (STM) spectroscopic studies of an electron doped superconductor, Pr<subscript>0.88</subscript>LaCe<subscript>0.12</subscript>CuO<subscript>4-&#948;</subscript> (PLCCO). The electron doped compounds form an interesting venue for STM studies for many reasons. In the hole-doped materials, especially in the underdoped side of the phase diagram, there is mounting evidence of a second gap that survives to high temperatures (high temperature pseudogap) that may have a different origin from superconductivity. This complicates studies of the temperature dependence of the superconducting gap in these materials. In PLCCO however, there is little evidence for a high temperature pseudogap potentially allowing us to address the question of the temperature evolution of the superconducting gap without the complication of a second gap. Secondly, the low T<subscript>c</subscript> of the optimally doped materials makes it easily accessible to temperature dependent STM studies. Finally, while hole-doped materials have been extensively studied by scanning tunneling microscopy (STM), there have been no detailed STM spectroscopic studies on the electron doped compounds. </p> <p> In the first part of the thesis, we investigate the effect of temperature on the superconducting gap of optimally doped PLCCO with T<subscript>c</subscript> = 24K. STM spectroscopy data is analyzed to obtain the gap as a function of temperature from 5K to 35K. The gap is parameterized with a d-wave form and the STM spectra are fit at each temperature to extract the gap value. A plot of this gap value as a function of temperature shows clear deviations from what is expected from BCS theory. We find that similar to the hole-doped superconductors a fraction of the surface still shows a gap above T<subscript>c</subscript>. The implications of our finding to the pseudogap phase are discussed.</p> <p> In the second part of the thesis, STM spectra are analyzed to determine the effect of impurities or vacancies on the local density of states. Electron doped superconductors require a post-annealing process to induce superconductivity. It is claimed that Cu vacancies in the CuO<subscript>2</subscript> planes which suppress superconductivity are healed by this process. This implies that for the same doping, a sample with higher T<subscript>c</subscript> should have fewer impurities compared to a sample with lower T<subscript>c</subscript>. We studied two PLCCO samples with 12% Ce doping; one with higher T<subscript>c</subscript> (24K) and the other with lower T<subscript>c</subscript> (21K). Through quasiparticle scattering study we find that there are more impurities in 21K samples than 24K sample, consistent with the picture of Cu vacancies in as grown samples. Finally, we present a discussion of the bosonic modes observed in the STM spectra and their connection to the spin excitations measured by neutron scattering.</p> / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Wong Wai Lun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 119-125). / Abstract also in Chinese. / Acknowledgments --- p.i / Legend for Figures --- p.ii / Legend for Tables --- p.iv / Abstract --- p.v / Abstract in Chinese --- p.ix / Chapter Chapter I --- Introduction --- p.1 / Objective --- p.5 / Chapter Chapter II --- Literature Review / Chapter II.1. --- Anatomy of the urinary system --- p.6 / Chapter II.2. --- Physiology of the urinary system --- p.10 / Chapter II.3. --- Methods for investigating the urinary system --- p.12 / Chapter II.3.1. --- Plain film radiography --- p.12 / Chapter II.3.2. --- Excretory Urogram --- p.12 / Chapter II.3.3. --- Ultrasound --- p.13 / Chapter II.3.4. --- Computed Tomography --- p.15 / Chapter II.3.5. --- Renal Angiography --- p.16 / Chapter II.3.6. --- Magnetic Resonance Imaging (MRI) --- p.16 / Chapter II.3.7. --- Radionuclide Imaging --- p.17 / Chapter II.4. --- Radiopharmaceuticals for renal parenchyma imaging --- p.17 / Chapter II.4.1. --- Tc-99m GHA --- p.18 / Chapter II.4.1.1. --- Chemistry of Tc-99m GHA --- p.18 / Chapter II.4.1.2. --- Preparation --- p.18 / Chapter II.4.1.3. --- Doses --- p.18 / Chapter II.4.1.4. --- Biological behavior --- p.19 / Chapter II.4.2. --- Tc-99m DMSA / Chapter II.4.2.1. --- Chemistry of Technetium-99m Dimercaptosuccinic Acid (Tc-99m DMSA) --- p.20 / Chapter II.4.2.2. --- Chemical property of Tc-99m DMSA --- p.21 / Chapter II.4.2.3. --- Preparation --- p.22 / Chapter II.4.2.4. --- Radiochemical purity measurement --- p.22 / Chapter II.4.2.5. --- Doses --- p.23 / Chapter II.4.2.6. --- Pharmacokinetic of Tc-99m DMSA --- p.23 / Chapter II.4.2.7. --- Renal handling of injected Tc-99m DMSA --- p.25 / Chapter II.5. --- General consideration for quantitative uptake measurement in organs --- p.26 / Chapter II.5.1. --- Clinical significance of renal Tc-99m DMSA uptake --- p.28 / Chapter II.5.2. --- Special consideration and problems for quantitative renal Tc-99m uptake measurement --- p.29 / Chapter II.5.3. --- Suggestions and solutions for quantitative renal Tc-99m uptake measurement --- p.29 / Chapter II.5.3.1. --- Planar images Vs SPECT images for quantification --- p.29 / Chapter II.5.3.2. --- Background subtraction --- p.31 / Chapter II.5.3.3. --- Choice of location for background ROI --- p.32 / Chapter II.5.3.4. --- Attenuation --- p.35 / Chapter II.5.3.5. --- Principle of the conjugate view method --- p.36 / Chapter II.5.3.6. --- Body thickness and kidney depth measurement --- p.37 / Chapter II.6. --- Glomerular Filtration / Chapter II.6.1. --- Introduction --- p.39 / Chapter II.6.2. --- Gold standard for GFR measurement --- p.40 / Chapter II.6.3. --- Laboratory studies for the measurement of glomerular filtration : Serum Creatinine and Blood Urea Nitrogen (BUN) levels --- p.41 / Chapter II.6.3.1. --- Calculation of Creatinine Clearance Rate --- p.43 / Chapter II.6.3.2. --- Critique for using creatinine clearance as a measurement of renal function --- p.44 / Chapter II.6.3.3. --- Limitation of the serum creatinine concentration used alone as a measurement of renal function --- p.46 / Chapter II.6.4. --- Radionuclide technique for the assessment of the glomerular function --- p.48 / Chapter II.6.4.1. --- Diethylene Triamine Penta Acetic acid (DTPA) --- p.49 / Chapter II.6.4.2. --- Methods / Chapter II.6.4.2.1. --- Measurement of Glomerular Filtration Rate using Tc-99m DTPA with single injection techniques --- p.51 / Chapter II.6.4.2.2. --- Compartment model --- p.52 / Chapter II.6.4.2.2a. --- Two-compartment model --- p.52 / Chapter II.6.4.2.2b. --- Single-compartment model --- p.54 / Chapter II.6.4.2.3. --- Single blood sample technique: a modification of Tauxe's OIH method in which counts in a single plasma sample correlated with a GFR nomogram --- p.56 / Chapter II.6.4.2.4. --- Gamma camera based method --- p.58 / Chapter II.6.4.2.4a. --- Gates-modification of Schlegel's OIH technique --- p.58 / Chapter II.6.4.2.4b. --- Critique for the Gamma camera technique for measuring GFR --- p.62 / Chapter II.7. --- The relationship between the Tc-99m DMSA uptake and GFR --- p.67 / Chapter Chapter III --- Material and Methods --- p.69 / Chapter III.1. --- Subjects and Sampling Methods --- p.69 / Chapter III.2. --- Quantitation of Absolute DMSA uptake --- p.70 / Chapter III.2.1. --- Parameters for Tc-99m DMSA uptake study --- p.70 / Chapter III.2.1.1. --- Materials and methods --- p.70 / Chapter III.2.1.1.1. --- Instrumentation --- p.70 / Chapter III.2.1.1.2. --- Dosage --- p.70 / Chapter III.2.1.1.3. --- Optimum acquisition start time --- p.70 / Chapter III.2.1.1.4. --- Length of acquisition time --- p.71 / Chapter III.2.1.1.5. --- Acquisition parameter --- p.71 / Chapter III.3. --- Calculation of absolute renal DMSA uptake --- p.72 / Chapter III.3.1. --- Attenuation Coefficient factor(μ) --- p.73 / Chapter III.3.2. --- Table attenuation --- p.75 / Chapter III.3.3. --- Body thickness measurement --- p.77 / Chapter III.3.4. --- Decay correction --- p.78 / Chapter III.3.5. --- Calculation of DMSA uptake --- p.78 / Chapter III.3.6. --- Counting dose injected --- p.80 / Chapter III.3.7. --- Calculation of absolute quantitation of Tc-99m DMSA uptake --- p.80 / Chapter III.3.8. --- Dose infiltration --- p.81 / Chapter III.4. --- GFR measurement --- p.82 / Chapter III.4.1. --- Instrumentation --- p.82 / Chapter III.4.2. --- Methods --- p.82 / Chapter III.5. --- Statistical and analytical methods --- p.84 / Chapter Chapter IV --- Results --- p.87 / Chapter IV. 1. --- Characteristics of experimental subjects and their serum creatinine profile --- p.88 / Chapter IV.2. --- Absolute Tc-99m DMSA uptake / Chapter IV.2.1. --- The change of absolute Tc-99m uptake with time --- p.89 / Chapter IV.2.2. --- Absolute Tc-99m DMSA uptake measurement at 6 and 24 hours --- p.90 / Chapter IV.2.3. --- Gender difference in absolute Tc-99m uptake measurement at 6 hour --- p.92 / Chapter IV.3. --- GFR measurement --- p.93 / Chapter IV.3.1. --- GFR measurement by single (3hr) and double (1&3 hrs) plasma sampling --- p.93 / Chapter IV.3.2. --- Gender difference in GFR measurement using single plasma sampling --- p.96 / Chapter IV.4. --- Univariate Correlation --- p.97 / Chapter IV.4.1. --- Correlation between GFR using single plasma sampling and absolute Tc-99m uptake --- p.97 / Chapter IV.4.2. --- Correlation between GFR using single plasma sampling and plasma creatinine levels --- p.98 / Chapter IV.4.3. --- Correlation between anthropometric variables on GFR(3 hr) --- p.99 / Chapter IV.4.4. --- Correlation between anthropometric variables and serum creatinine plasma level on absolute Tc-99m DMSA uptake measurement at 6 hour --- p.101 / Chapter IV.4.5. --- Multiple linear stepwise regression --- p.103 / Chapter Chapter V. --- Discussion / Chapter V. 1 --- . Review of the study --- p.104 / Chapter V.1.1. --- Experimental subjects and their absolute Tc-99m DMSA uptake (%) at 6 hr --- p.104 / Chapter V.1.2. --- Experimental subjects and their GFR(3 hr) --- p.105 / Chapter V.2. --- Discussion on subject --- p.105 / Chapter V.2.1. --- Subject preparation --- p.106 / Chapter V.3. --- Discussion of method --- p.106 / Chapter V.3.1. --- Equipment --- p.106 / Chapter (a) --- Dose calibrator --- p.106 / Chapter (b) --- The sensitivity of the head 1 and 2 of the gamma camera --- p.106 / Chapter (c) --- Validation of quantification of injected activity by gamma camera method--------constancy of performance for gamma camera --- p.110 / Chapter (d) --- LEHR Collimator --- p.112 / Chapter (f) --- Dead time loss --- p.112 / Chapter V.4. --- Discussion on measurement --- p.113 / Chapter (a) --- Length of acquisition time --- p.113 / Chapter (b) --- Attenuation Coefficient factor (\x) --- p.113 / Chapter (c) --- "Body thickness, L, measurement" --- p.113 / Chapter (d) --- Optimum acquisition time for data collection --- p.115 / Chapter v.5. --- Discussion on overall error estimation --- p.115 / Chapter (a) --- Tc-99m DMSA uptake measurement at 6 hr --- p.115 / Chapter (b) --- GFR measurement by single (3 hr) sample --- p.116 / Chapter Chapter VI --- Conclusion --- p.117 / Reference --- p.119 / Appendix I --- p.126 / Appendix II --- p.128 / Appendix III --- p.134

This thesis examines the application of two evolutionary computation techniques to two different aspects of open channel flow. The first part of the work is concerned with evaluating the ability of an evolutionary algorithm to provide insight and guidance into the correct magnitude and trend of the three parameters required in order to successfully apply a quasi 2D depth averaged Reynolds Averaged Navier Stokes (RANS) model to the flow in prismatic open channels. The RANS modeled adopted is the Shiono Knight Method (SKM) which requires three input parameters in order to provide closure, i.e. the friction factor (\(f\)), dimensionless eddy viscosity (λ) and a sink term representing the effects of secondary flow (Γ). A non-dominated sorting genetic algorithm II (NSGA-II) is used to construct a multiobjective evolutionary based calibration framework for the SKM from which conclusions relating to the appropriate values of \(f\), λ and Γ are made. The framework is applied to flows in homogenous and heterogeneous trapezoidal channels, homogenous rectangular channels and a number of natural rivers. The variation of \(f\), λ and Γ with the wetted parameter ratio (\(P_b\)/\(P_w\)) and panel structure for a variety of situations is investigated in detail. The situation is complex: \(f\) is relatively independent of the panel structure but is shown to vary with P\(_b\)/P\(_w\), the values of λ and Γ are highly affected by the panel structure but λ is shown to be relatively insensitive to changes in \(P_b\)/\(P_w\). Appropriate guidance in the form of empirical equations are provided. Comparing the results to previous calibration attempts highlights the effectiveness of the proposed semi-automated framework developed in this thesis. The latter part of the thesis examines the possibility of using genetic programming as an effective data mining tool in order to build a model induction methodology. To this end the flow over a free overfall is exampled for a variety of cross section shapes. In total, 18 datasets representing 1373 experiments were interrogated. It was found that an expression of form \(h_c\)=A\(h_e\)\(^{B\sqrt S_o}\), where \(h_c\) is the critical depth, \(h_e\) is the depth at the brink, \(S_o\) is the bed slope and A and B are two cross section dependant constants, was valid regardless of cross sectional shape and Froude number. In all of the cases examined this expression fitted the data to within a coefficient of determination (CoD) larger than 0.975. The discovery of this single expression for all datasets represents a significant step forward and highlights the power and potential of genetic programming.

The upgrade of urban water distribution systems (UWDS) amidst uncertain global change pressures is a challenging problem. To deal with this dilemma water utilities require approaches that enable UWDS to be transitioned at a minimal technical and socio-economic impact as uncertainties become known. A review of approaches for upgrading UWDS shows that existing cost models are skewed towards operation and maintenance costs without consideration for future transitionability. This thesis describes approaches for the sustainable transition of UWDS and their application on case studies. The thesis develops a conceptual framework for the analysis of UWDS transitions. It then develops a Socio-economic Impact Indicator (SII) framework based on Multi Criteria Decision Analysis and the Analytical Hierarchical Process to estimate impacts in an urban area due to UWDS transitions. It also develops an approach for modelling socio-technical transitions based on multinomial logistic regression. The thesis then develops an UWDS transition design approach that considers not only operation and maintenance costs (leakage and burst costs) but also transitionability and future socio-technical impacts costs. The developed approaches have been tested on case studies as proof of concept. Maximum cost saving can be realised when existing UWDS are upgraded with consideration of future UWDS transitionability.

Accurate modelling, both numerical and physical, is vital to further our understanding of flow in rivers. This thesis examines both methods of flow applied to two distinct problems; numerical modelling of flow in simple channels with heterogeneous roughness and physical modelling of flow in compound channels with skewed floodplains. In this thesis, the Shiono and Knight Method (SKM) is applied to homogeneously and heterogeneously roughened channels. The SKM is shown to be capable of accurately predicting the lateral distributions of depth-averaged velocity and boundary shear stress for both roughness types. Furthermore, the percentage shear force on the wall of a channel is accurately obtained for both roughness types and guidance is given as to the choice of the three calibration coefficients the model requires, namely f, l and G representing friction, eddy viscosity and secondary flow respectively. Finally, physical modelling has been undertaken on compound channels with skewed floodplains in addition to a full review of the work undertaken at a larger scale in the Flood Channel Facility. As a result appropriate expressions for shear force and apparent shear forces acting on the horizontal and vertical interfaces have been established.

The frequency and intensity of flooding has increased over the last few decades. The UK is not an exception, despite large amounts of money invested every year in flood risk management, flooding is a prevalent issue in the country causing millions of losses every year. In this thesis we contribute to debate on the economic valuation of flood risk in the UK from a household perspective using a non-market valuation approach from the housing market. In the first chapter we investigate the capitalisation of flood risk in property prices by means of a meta-analysis. In the second and third chapters we use a repeatsales specification of a hedonic model to investigate the capitalisation of flood defences and the effect of flooding in the price of properties in England. The results suggest that the current benefit estimates used by the UK Government to determine the allocation of resources to flood relief projects results in a misallocation of resources. We highlight the importance of rethinking the strategy for flood risk management in the UK. Our results provide a sound economic basis to guide the allocation of resources for flood alleviation strategies in a socially efficient way.