Gel-precipitated (U, Th) spheres produced at AERE Harwell, were investigated to study the development of the structure of the gel spheres at various stages of production. Various parameters including surface area, true (matrix) and geometric densities, porosity, crystallite size, compliance and related properties were investigated. A careful examination of whole and cleaved spheres by Scanning Electron Microscope was also carried out. The xerogel spheres were debonded in a tubular furnace in an atmosphere of CO[2] to remove or decompose the gelling agent (polymer) and other volatiles which might be present. The isothermal and constant-rate-of-heating (CRH) sintering behaviour of partially and fully debonded spheres were studied. In the latter work the shrinkage data of a batch of spheres were obtained from geometric (Hg) density measurements instead of the conventional dilatometric method used for pellets. The study has shown that ageing and heavy metal composition have a substantial influence on the structure of the debonded spheres, the rate of sintering, and the microstructure of the sintered products. Ageing and increasing amount of thorium generally retards sintering. Partially debonded (to 750°C) spheres sinter faster than fully debonded spheres and the former also develop larger grains on sintering. Gel-precipitation is a versatile technique which can be used to produce spheres which sinter to > 98% of the theoretical density at a comparatively low temperature (≈ 1400 C). Grain-boundary diffusion was found to be the probable dominant material transport mechanism in the sintering of (U, 30% Th)O[2].

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According to current climate change predictions for the UK, summers are expected to become dryer and hotter in the future. This has potentially serious implications for overheating of naturally ventilated office buildings, many of which already fail to perform under current heatwave conditions. This thesis addresses the summer performance of such buildings under current and future climates by means of building performance simulation. Current industry standard weather datasets for building performance simulation are not however, suited to the assessment of the potential impacts of a changing climate. This work describes the integration of future climate scenarios into widely used weather file formats and critically assesses the resulting weather datasets. Simulations of a case study building at the University of Southampton highlight the potential impact of climate change on future summer overheating inside naturally ventilated buildings. The results of these simulations are compared to monitored data from the case study building during an extended heatwave period in the summer of 2006. It is shown that the present day performance of a naturally ventilated building under an extended heatwave period can give an indication of its likely performance during a projected typical hot summer in the 2050’s under a medium-high emissions scenario. A second case study building serves to highlight that building designs and building services solutions which are suitable for retaining acceptable indoor comfort levels during current heatwave periods, are likely to be suitable to alleviate summer overheating under the predicted warmer future climates. Further simulations, encompassing various locations throughout the UK emphasize the need for timely refurbishment of naturally ventilated office buildings within the next few decades to avoid increasing numbers of existing buildings failing to perform under the predicted future summer conditions.

This thesis delivers a significant contribution to knowledge through the construction of a validated framework, that supports value creation for the QS organisation, when adopting and implementing BIM. It also reports on the current misconceptions in terms of the threat posed by Building Information Modelling (BIM) to the QS profession. This research has found that the QS role will evolve and transform with the opportunities that BIM presents, and will survive as consequence of value creation. The thesis identified 9 critical success factors, 5 success factors specific to BIM and 4 success factors specific to the organisation, all of which contributed towards the development of the framework. The study was conducted by adopting a mixed methods design by extracting knowledge from the literature review to inform the semi structured interviews, the results of which informed the design of the questionnaires and finally all results informed the development of the framework which was finally validated via a focus group. The major findings of this research were threefold. Firstly, from a theoretical perspective it was found that a unified understanding of BIM definition aligning the perceptions of the individual QS with those of the organisation, was the foundation from which to develop the framework. It was found to be of far more significance than most theorist purport, as the adoption process requires systemic transformation at all levels within the organisation, based on a unified vison. This stems from individual and organisational perceptions of BIM, which in turn go back to definition. Secondly, the research identified that the BIM barriers reported by the theorists are not the dominant barrier to implementation, but it is more specifically the lack of understanding of the benefits of BIM to the individual, that restrict adoption. Finally, the research has provided the QS organisation with a holistic overview of the key critical success factors necessary to support BIM level maturity and ultimately value creation.

Fast urban growth and topographical factors across Europe have contributed to an increase in the total number of hillside residential buildings. In the case of Portugal, a clear need for hillside building design which can fully benefit from the thermal advantage of slope terrains has been identified. Although the energy efficiency of ground-integrated architecture has been the subject of numerous research works, only a small number of those research projects have focused on the thermal potential of ground-integrated buildings constructed on sloped terrains. The research presented in this thesis sheds light on the energy saving potential of ground-integrated buildings on slope terrains and provides design guidelines based on the research findings. Firstly, through mathematical calculations, this research demonstrates that ground thermal patterns under slope terrains are different from those below flat areas. In Lisbon, terrain inclinations have higher annual ground thermal potential than flat terrains. It is furthermore noted that a transitional zone is formed immediately before and after a slope. As a result of these investigations it is concluded that slopes of 30° to 40° provide the best annual ground thermal potential. Secondly, through a parametric study using EnergyPlus to simulate ground heat transfer, it is show that ground integration affects buildings thermal performance. It is found that the greater the ground integration the lower the energy demand, but also that total ground integration fails to provide the best solution. Concerning the levels of slope integration, the steeper the slope, the greater the average annual savings. However the thermal advantage difference between steeper slopes such as those of between 30° to 50° is small. Regarding the impact of building design on annual saving potential, it is found that building design does affect models’ thermal performance and that its impact is greatest with shallower slopes. It is therefore concluded that in temperate climates, new hillside constructions can take advantage of the energy saving potential of ground integration into slope terrain and of slope building designs.

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Research relating to the potential impacts of climate change on UK housing has increased in recent years. The future performance of dwellings that are currently considered sustainable may change under a changing climate. For example, well insulated, air tight homes that are energy efficient and comfortable now may be at risk of overheating in the future. Decision-making for sustainable house designs may become more challenging regarding dwellings that will perform well now and be resilient to climate change risks, such as overheating, in the future. This study evaluates the effect of overheating risk and future climatic uncertainty in designing UK dwellings. The main focus of the research is on the thermal performance of the external building envelope. The foremost aim is to future proof current designs in order to provide the best possible thermal comfort under likely warmer weather conditions produced by climate change. This research examines a number of constructional design options to reduce energy consumption and improve thermal comfort on the basis of climate change predictions up to 2080. The study develops a methodology by means of computer simulations to assess and predict the performance (in terms of total energy input, both heating and cooling, required to maintain thermal comfort) in a range of current, ‘high performance’ construction systems used on simple and typical UK house models in London and Manchester. The findings of this study show that UK sustainable homes, in their present format, are susceptible to a future overheating risk. It is argued that the substantial part of the overheating risk can be alleviated by the integration of modern smart materials and conventional design solutions, such as shading devices and earth-to-air heat exchangers (EAHE). The research also proposes a new method of integrating phase change materials into the building envelope to reduce domestic cooling loads and overheating hours in the coming decades.

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