Greywater (GW) recycling for non-potable uses (e.g. urinal and toilet flushing) provides an urban water management strategy to help alleviate this risk by reducing mains water demands. The research described in this thesis proposes scenarios for an innovative cross-connected system that collects GW from residential buildings and recycles it for toilet/urinal flushing in both residential and office buildings. The capital cost (CAPEX), operational cost (OPEX), the carbon costs (embodied and operational), and water saving potential are calculated for individual block of residential and office buildings and shared GW recycling system between both building blocks in an urban mixed-use regeneration area in the UK assuming two different treatment processes; a membrane bioreactor (MBR) and a vertical flow constructed wetland (VFCW). The Net Present Value (NPV) method was used to compare the financial performance of each considered scenario from where it was found that over a 15 year period a shared GW recycling system (MBR) was the most economically viable option with an NPV of £213.11k and potable water savings of almost 27% (compared with mains water only system); 12% (compared with individual block GW recycling system). However, over the same time period it was shown that shared CW treatment had the lowest carbon emissions, saving up to 11% (compared to conventional mains supply), whereas a shared MBR increased carbon emissions by up to 27%. The sensitivity of this financial and emission model was assessed considering six parameters (i.e. water supply and sewerage charges, discount rate(s), electricity charges, service life, building description, user behaviour and improved technological efficiency).

Traditionally buildings are designed assuming they will be loaded by a statistically stationary atmospheric boundary layer wind with a logarithmic mean vertical profile. However, there are other wind types which differ from this. For example, the thunderstorm downburst is highly non-stationary and has a different vertical velocity profile. This presents a problem as existing wind tunnels, analysis techniques, scalings and assumptions about wind loading may be incorrect for the downburst. To address these issues a pulsed impinging jet simulator was developed. The flow field was scaled and then compared to a full scale event using non-stationary analysis parameters based upon wavelet analysis. When scaled to a medium intensity downburst the simulator had scales of: length, 1 : 1000, velocity 1 : 1.67 and time 1 : 1109. However, the scalings were not self-consistent, suggesting it was only capable of a partial simulation, i.e. it could only simulate part of the velocity time history of a full scale down burst. Pressure, force and lift coefficients were then calculated for a model CAARC building placed in the simulator at the location of maximum velocity. A comparison to ABL results for a single and interference effects case revealed that, in the single building case, the downburst wind loads exceeded the ABL case near the base of the building, where wind speeds exceeded that of the ABL. The interference case was more complex, generally interference effects were reduced in downburst flows. However, at certain yaw angles and separation distances exceedances over the single building case occurred. Further research is still needed into the interference effects phenomenon in downburst flows.

Hand movements reveal the temporal characteristics of visual attention Optimisation of potable water treatment could result in substantial cost savings for water companies and their customers. To address this issue, computational modelling of water treatment works using static and dynamic models was examined alongside the application of optimisation techniques including genetic algorithms and operational zone identification. These methods were explored with the assistance of case study data from an operational works. It was found that dynamic models were more accurate than static models at predicting the water quality of an operational site but that the root mean square error of the models was within 5% of each other for key performance criteria. Using these models, a range of abstraction rates, for which a water treatment works was predicted to operate sufficiently, were identified, dependent on raw water temperature and total organic carbon concentration. Genetic algorithms were also applied to the water treatment works models to identify near optimal design and operating regimes. Static models were identified as being more suitable for whole works optimisation than dynamic models based on their relative accuracy, simplicity and computational demands.

1-3 connectivity piezoceramic-polymer composites that can operate above 30 MHz are in demand to improve spatial resolution for biomedical ultrasound imaging applications. However, increasing the operational frequency of these materials is extremely challenging as ultrafine dimensions are required in conventional composite designs. An innovative randomised composite design has been previously reported to relax overall dimensional restrictions and to eliminate spurious resonance modes. However, realisation of such a design presents a significant challenge to conventional fabrication techniques. In this work, a novel moulding approach based on a combination of gel casting and soft lithography techniques has been developed for producing random composites. A maximum green strength of 38 MPa has been obtained in the gel-cast green bodies. Irregular-shaped ceramic segments with feature sizes varying from 2 to 50 μm and aspect ratios up 70 have been achieved. Random piezocomposites with operational frequencies up to 100 MHz and thickness coupling factors over 0.5 have been fabricated and demonstrated. Two complete transducers working at 30 MHz and 70 MHz incorporating the random composites have been produced and characterised. Results from the transducers demonstrated their functional performance and showed the potential of the novel random piezocomposites for high frequency ultrasound applications.

The research analyses the behaviour of the flow in an open channel with self-formed banksides, with the purpose of exploring the ability of a numerical model to predict such geometries. The strategy consists in contrast a numerical model with physical model data. With respect to the numerical model, it is divided in two main parts, the first one describing the flow and the second one defining the cross sectional geometry. For the first part, a quasi 2D flow structure was selected to model the flow, i.e. the Shiono and Knight Model (SKM) (Shiono and Knight, 1991), due to its simplicity and flexibility. It allows users to incorporate the variation of friction factor, \(f\), secondary flow gradient, Γ, and dimensionless eddy viscosity, \(λ\), across the section. In order to calculate the bankside geometry, the Yu and Knight Model (1998) was chosen, because it relates the equilibrium of particles on the boundary to the shear stress, \(τ\)\(0\), distribution. With respect to the physical model, the shape of a self-formed bankside has been reproduced and assessed in a tilting flume, in order to identify its flow pattern by measuring velocity and shear stress. Such data was used for calibration and validation of the numerical model. The cross section was inspired in the bankside obtained by Ikeda (1981), fitting it into a flume 46cm wide. The experiment consists of testing the channel by three different slopes, three depths and two surfaces (smooth and rough), mapping velocity and measuring shear stress on the boundary across the section. The novelty of the work is to improve the flow estimation for this type of cross section, incorporating the secondary flow, and subsequently enhancing the approximation to the geometry that will be formed in alluvial channels.

This thesis present results relating to a series of laboratory experiments investigating the velocity field in order to provide an understanding into the flow structures by describing the mechanisms and transport features of heterogeneous (patchy) flexible and rigid strip vegetation flow interaction with gravel roughness which could be used to understand sediment transport in the future. The experimental results were examined in a context of shear layer arising as a result of flexible and rigid vegetation patchy roughness distribution with gravel roughness. It is shown that relative to a gravel bed, the vegetated section of the channel generally resembles a free shear layer. The resistance within the vegetation porous layer reduces the velocity and creates a transition of high velocity flow across the interface at the top of vegetation; of primary importance is the shear layer at the top of vegetation and roughness boundary regions which are shown to influence and dominate the overall momentum transport. These results have been used to calibrate a numerical model for the depth-averaged streamwise and boundary shear stress distribution using the Shiono and Knight Method (SKM). The model demonstrated approximately 90% accuracy in depth-averaged streamwise velocity distribution in comparison with the experimental data.

This thesis reports the results of DEM (Discrete Element Method) simulations of the behaviour of granular material for axisymmetric compression and plane strain deformation under both drained and undrained conditions. The aim is to study the behaviour of saturated granular material using DEM and the objectives of this thesis are: • to explore the drained behaviour of granular material using DEM • to explore the undrained behaviour of loose samples of granular material with and without preshearing history, using DEM • to compare axisymmetric compression and plane strain behaviour of a granular material under both drained and undrained conditions, using DEM A servo-control mode with constant mean stress is used to model drained simulations, and a strain-control model with constant volume is used to model undrained simulations. A periodic cell is used for all the simulations. For the drained simulations, the results of both dense and loose systems are presented, and all the systems reach a unique critical state at large strains. For the undrained simulations, mainly the results of loose systems are presented. The influence of preshearing history is also examined for a loose system under undrained axisymmetric compression conditions. The concept of liquefaction is shown to strongly correlate with mechanical coordination number, and liquefaction is shown to be related to structural mechanism. An attempt has been made to compare the axisymmetric compression and plane strain deformation for the drained and undrained conditions respectively. Shear strength criteria are examined and the Lade criterion is shown to be the most appropriate failure criterion.

Fuel consumption by road vehicles is the most significant component of total road transport energy use and is significantly affected by driving style. This research was aimed at improving the effectiveness and efficiency of driver training for fuel economy for drivers involved in the management and operations of a road network in England. A unique approach to driver training was designed and tested with 94 drivers of heavy, medium and light vehicles. The improvement in fuel economy (in terms of MPG) for the first month after the training was observed to improve by up to 7%. The improvements reduced at varying rates after the training suggesting the need for regular refresher training. The behaviours of the drivers were also observed to change as a result of the training, towards styles more suited to achieving a better fuel economy. The results suggest that both linear and logarithmic models could be suited to predicting the drivers' performances and could be integrated in models of the type of HDM-4 which currently lack such capability. The driver training methodology was found to be more cost effective than the Safe And Fuel Efficient Driving (SAFED) training method recommended by the Department for Transport (DfT).

The results of a laboratory investigation into the behaviour of small groups of up to five granular columns, in soft clay, loaded by various foundation configurations under rapid undrained conditions is presented. Columns with a constant layer length to diameter ratio in both floating and end-bearing conditions are considered. Electronic instrumentation was developed to record boundary stresses and displacements and radiographic techniques were employed to measure internal displacements and strains in the columns and clay. Extensive use of interactive mainframe and mini computers was made in collecting, storing and processing the laboratory data. The improvement in bearing capacity and reduction in settlement was found to be strongly dependent on the relative column and clay areas in contact with a foundation. The column end-bearing condition was also a contributory factor. The mechanism of column and clay deformation was observed as being dependent on the boundary conditions. Column yield occurred as a general shear failure or a local shear failure depending on the relative sizes of the clay and column areas. Laboratory results showed that direct analogy with conventional piles or pile groups cannot be made. An empirical relationship for estimating the improvement in bearing capacity and settlement is proposed.

The continuous global demand for infrastructure due to persistent increase in population growth implies that more aggregate and cement would be required in concrete production. This would eventually lead to more extraction and depletion of natural resources and increased carbon emission. The aim of this research work was to develop high performance concrete using recycled coarse aggregate, microsilica, and synthetic macro fibre with the object to boost higher use of recycled coarse aggregate in the construction industry. Concrete was designed for 28-day compressive cube strength of 50MPa, high workability (60-180mm) and a constant water-cement ratio of 0.39. Microsilica was incorporated up to 20% of cement content at 5% intervals, while the natural coarse aggregate substitution by recycled coarse aggregate ranges between 0 - 100% at 25% interval. Workability, compressive cube strength, tensile splitting strength, flexural strength, static elastic modulus, and water permeability tests including fatigue assessment were conducted respectively. Results confirmed that, the incorporation of 15% microsilica with 50% recycled coarse aggregate fraction produced 28-day compressive cube strength which exceeds the characteristics and target mean compressive cube strength of the control mix which are 50MPa and 63.1MPa respectively. The result suggests that there is a potential to increase the optimum fraction of recycled aggregate from 30-50% in concrete.