The application of high strength steels (HSS) in the construction industry can lead to more economic design and profound sustainability benefits. To facilitate their use in modern practice, most international structural design codes have included HSS within their contents. Due to limited test data at the time of publishing, HSS design provisions are largely based on those for mild steel, with some restrictions, due to HSS’s inferior ductility and strain-hardening characteristics. Hence, further investigation on the applicability of such design specifications to HSS is required. To this end, within the present research work the structural performance of high strength steel structures employing square and rectangular hot-finished hollow sections is rigorously investigated. Meticulously generated finite element models of individual structural components are validated against test data and subsequently used for the generation of additional structural performance data through the execution of parametric studies. Implementing the aforementioned methodology, focus is also placed upon the structural performance of HSS trusses, whilst the possibility of applying prestress to them to enhance their behaviour is examined. Based on the obtained results, the suitability of current codified design methods to HSS is assessed and appropriate design recommendations are made.

Cannabinoids suppress Th1 immunity in a variety of models including infection with the intracellular pathogen Legionella pneumophila (Lp). To examine the cellular mechanism of this effect, mouse bone marrow-derived dendritic cells (DCs) were studied following infection and drug treatment. DCs produced high levels of IL-12p40 following Lp infection. THC suppressed this cytokine response in a concentration-dependent manner and the endocannabinoids 2-arachidonoyolglycerol and virodhamine less potently suppressed cytokine production. DCs expressed mRNA for cannabinoid receptor 1 (CB1), CB2, and transient receptor potential vanilloid type 1 (TRPV1); furthermore, inhibition of Gi signaling by adding pertussis toxin completely attenuated the suppression induced by low concentrations of THC but not at high concentrations. In addition, the THC suppression was partially attenuated in DC cultures from CB1 and CB2 knockout mice and in cultures from normal mice co-treated with THC and cannabinoid receptor antagonists. Cytokine suppression was not attenuated by pretreatment with the TRPV1 antagonist capsazepine, suggesting that Gi signaling and cannabinoid receptors, but not TRPV1, are involved in THC-induced suppression of DC potential to polarize the development of naïve T cells to be Th1 cells. Besides IL-12, THC suppressed other DC polarizing characteristics such as the expression of MHC class II and co-stimulatory molecules CD86 and CD40, as well as the Notch ligand Delta 4. However, THC treatment did not affect other DC functions such as intracellular killing of Lp and Lp-induced apoptosis. Testing the capacity of THC to suppress DC polarizing function with T cells showed that DCs infected in vitro with Lp were able to immunize mice when injected prior to a lethal Lp infection; however, the immunization potential along with Th1 cytokine production was attenuated by THC treatment of the cells at the time of in vitro infection. In addition, THC-treated and Lp-infected DCs poorly stimulated primed splenic CD4 T cells in culture to produce IFN-gamma (IFN-y); however, this stimulating deficiency was reversed by adding recombinant IL-12p40 protein to the cultures. In conclusion, the data suggest that THC inhibits Th1 polarization by targeting essential DC functions such as IL-12p40 secretion and the maturation and expression of co-stimulatory and polarizing molecules.

This dissertation contains two studies that investigate the Mesozoic and Cenozoic tectonics of the western USA. The first study investigates shortening in the Sevier thrust belt of northeast Utah and southwest Wyoming. Cross section restoration suggests that there was ∼8-14 km of pre-Absaroka-thrust shortening above the Jurassic Preuss salt detachment (PSD), but not below it, in the hanging wall of the Absaroka thrust. Reflection seismic data show that the Crawford thrust is not offset along the PSD, indicating that the additional shortening on the Absaroka plate was transferred east before main movement on the Crawford thrust. Integration of surface and subsurface geology suggests slip from the Willard or Lost Creek thrust was transferred several tens of kilometers east along the PSD between ∼102-90 Ma.The second study investigates the low-temperature thermochronology of the Laramide Ranges. We dated 91 borehole and surface samples from basement-cored uplifts of the Rocky Mountain foreland (Wind River, Beartooth, Bighorn and Laramie Ranges), and the Uncompahgre Uplift, using the apatite (U-Th)/He system. (U-Th)/He ages generally increase with increasing elevation. Most samples show age dispersion of tens to hundreds of Myr. Several samples show correlations between (U-Th)/He age and effective U concentration (eU = [U] + 0.235[Th]), indicating that radiation damage has affected (U-Th)/He age. Many surface and near-surface samples have (U-Th)/He ages that are older than apatite fission-track ages.Forward and inverse modeling using a radiation damage diffusion model showed that (U-Th)/He ages may be widely dispersed, and may be older than apatite fission-track ages within a fossil partial retention zone. Most samples, however, do not exhibit the predicted (U-Th)/He age-eU correlation. We show that the effects of grain size can obscure (U-Th)/He age-eU correlations. Best-fit thermal histories from the inversion of age-eU pairs were extrapolated to other elevations to create model age-elevation plots. "Too-old" (U-Th)/He ages that are not within a fossil partial retention zone are likely due to He implantation from high-eU phases. Inverse modeling of (U-Th)/He age data suggests that rapid exhumation within the Laramide province began earlier in the Bighorn Mountains (before ∼71 Ma) than the Beartooth Range (before ∼58 Ma).

Energy consumption and Green House Gas (GHG) emissions from the UK built environment are reflective of the wider situation across Europe, where according to the Energy Performance in Buildings Directive (EPBD) "buildings account for 40% of total energy consumption in the Union" (European Commission, 2010). In December 2006 the UK Government announced a rapid transition to 'zero carbon' new buildings, as a key step forward in reducing GHG emissions from the domestic and non-domestic sectors (DCLG, 2006a; Weaver, 2007). The Passivhaus standard is the fastest growing energy performance standard in the world and in a growing number of regions across Europe it has been implemented as a mandatory minimum standard for all new buildings (iPHA, 2013). This thesis investigates the applicability of this low energy standard to the UK context, in comparison to conventional alternatives, by examining four inter-related themes: (i) in relation to climate change policy and the UK Government's plan for all new homes to be zero carbon from 2016; (ii) by addressing the limitations of the climate data currently used to design Passivhaus buildings, and developing a new methodology for creating higher resolution probabilistic climate data; (iii) by exploring the uncertainty about the future performance of Passivhaus dwellings in relation to future overheating risk and thereby proposing methods to improve whole life design optimization; (iv) by investigating the hygrothermal implications for new build and retrofit Passivhaus projects and highlighting areas where current risk assessment methods are inadequate. This thesis has argued that the transfer of the Passivhaus standard, or any advanced energy performance standard, from one country or region to another should be accompanied by an extensive programme of context specific research and application testing. The findings of this research have shown that the implementation of the Passivhaus standard, in its present format, in the UK is not without risk and uncertainty. This thesis concludes that that the majority of such risks can be substantially mitigated, through the incorporation of high resolution probabilistic climatic data, transient hygrothermal assessments and global sensitivity analysis techniques. The energy saving and thermal comfort potential of the Passivhaus approach have been shown to be substantial and therefore merit the challenges involved in addressing its successful implementation.

This work explores the influence of evolving anisotropy on the stress-strain behaviour of unsaturated soils and proposes a new constitutive elasto-plastic model for unsaturated soils accounting for evolving anisotropy. An extensive campaign of laboratory tests on both isotropically and anisotropically compacted soil samples under a wide range of stress paths was performed. These experimental data were then employed in developing the new model and investigating its performance. A programme of controlled suction triaxial testing was performed on unsaturated and saturated samples of Speswhite kaolin prepared by two different methods of compaction: isotropic and anisotropic. Tests involved probing stress paths, to investigate the initial forms of the yield surface for isotropically compacted and anisotropically compacted samples at different suction values, and how the yield surface was altered by plastic straining caused by loading stages or by wetting stages with significant collapse-compression. Tests also included shearing to failure, to investigate critical state conditions. Experimental results were interpreted in terms of mean net stress p ̅, deviator stress q and suction s as stress state variables and, alternatively, interpreted in terms of mean Bishop’s stress (defined as p^*=p ̅+ S_r s), deviator stress q and modified suction (defined as s^*=ns, where n is the porosity). The experimental results showed that fabric anisotropy can evolve during plastic straining even for a soil that starts isotropic but is then loaded to anisotropic stress states. Also, the results showed that fabric anisotropy can evolve during wetting stages that involve collapse-compression. Furthermore, the results showed no apparent influence of initial or evolving anisotropy on the critical state, where both the initially isotropic and initially anisotropic samples, loaded at various stress path slopes, showed nearly the same critical states. Critical states can be represented in the q:p ̅ plane by a series of parallel lines for different values of suction and the constant suction cross-sections of the yield surface can be represented by distorted ellipses in the q:p ̅ plane, intersecting the negative axis at the point of intersection of the corresponding critical state line. Alternatively, critical states can be represented in the q:p^* plane by a single straight line (for all values of suction) passing through the origin, and constant suction cross-sections of the yield surface can be represented in the q:p^* plane by distorted ellipses passing through the origin (suggesting that the yield surface expression is simpler when expressed in terms of q,p^* and s^* rather than in terms of q,p ̅ and s). A new constitutive model was formulated in terms of Bishop’s stresses and modified suction based on the above observations and other considerations such as that representing the coupling between mechanical and water retention behaviour is easier with Bishop’s stress than with net stress. The new anisotropic model combines features from the isotropic model for unsaturated soils of Wheeler et al. (2003a) with features for modelling of anisotropy taken from the anisotropic model for saturated soils S-CLAY1. The new anisotropic constitutive model was developed solely as a mechanical model, unlike the constitutive model of Wheeler et al. (2003a), which is a combined mechanical and water retention model. Model simulations of mechanical behaviour with the new anisotropic model were performed by using experimental values of S_r (with no attempt to predict values of S_r), because it was then possible to check whether mechanical aspects of the model were performing well. Model simulations showed that significant improvement in the accuracy of the predicted soil behaviour was achieved by incorporating the role of evolving fabric anisotropy. However, model performance appears more satisfactory in simulating soil behaviour under unsaturated conditions than under saturated conditions. Also, the model is not entirely successful in predicting some aspects of anisotropic soil behaviour such as differences in initial specific volume between isotropically and anisotropically compacted samples.

This work is concerned with the thermal and structural behaviour of reinforced concrete members in fire conditions. The numerical analyses of temperature histories and mechanical behaviour of reinforced concrete structural members subjected to fire are the major components of this research. In this thesis a non-linear finite element procedure is proposed to predict the temperature distribution history in the cross section of structural members, such as beams composed of reinforced concrete, in fire conditions. A theoretical analysis of heat and moisture transfer in concrete was made which incorporated the simplifications that energy transfer by convection and diffusion in concrete could be neglected. However, the effect of water evaporation in concrete was considered. The thermal properties of concrete were considered as temperature and moisture dependent and the thermal properties of steel as temperature dependent only. The fire conditions were described by standard time-temperature fire curves and convection and radiation boundary conditions were used. In order to validate the model a series of verification tests have been carried out through a quantitative comparison of the model predictions against known test results. Fairly good accuracy has been found. A non-linear finite element procedure for predicting the structural behaviour of the planar reinforced concrete members is also developed. The proposed procedure is based on "plane stress" theory and an iterative, secant stiffness formulation is employed. The complex features of structural behaviour in fire conditions, such as thermal expansion, shrinkage, creep, transient strains, cracking or crushing and change of material properties with temperature are considered in this model. Predictions from the model proposed are compared against experimental results, as well as against the model proposedb y previous researchers, and a better correlation to experimental data is found. It is shown that the secant stiffness approach can provide good numerical stability for the analysis of planar reinforced concrete members in fire conditions. The model proposed in this study has the potential to predict the fire resistance of a planar reinforced concrete members with an accuracy that is adequate for practical purposes if realistic material properties are available.

Risks and uncertainties are inherent in construction projects and if neglected these risks often lead to project cost and time overruns. Traditional methods of forecasting risks rely upon intuition and 'feel' which has proved inadequate for the needs of investors in modern construction projects. To cope with these recognised risks, a risk management framework, which consists four components (risk identification, risk classification, risk analysis and risk response), has been developed. The present research focuses on financial risks in construction management, and in particular, the development of enhanced quantitative, probabilistic methods for risk analysis. A comprehensive review of the treatment of risk and uncertainty in the construction industry is undertaken. Background knowledge of probability theory and Monte Carlo simulation is reviewed, as is previous investigations into construction network analysis and project economics. A comparison of the Programme Evaluation and Review Technique (PERT) and the Monte Carlo Simulation (MCS) methods in construction networks risk analysis is carried out. Two example projects are analysed by both methods. When applying the MCS method, a sensitivity analysis is carried out by investigating the effect of different probability distributions (Normal, Log-Normal, Beta, Triangular and Uniform) for individual activity durations, the number of simulations used and the effect of the manner of how the mean and standard deviations are set for the different probability distributions. A new analytical method, the Modified Stochastic Assignment Model (MSAM), is proposed for the prediction of project duration. Five example projects are used to demonstrate the validity of the MSAM and to illustrate its application in construction project evaluations. The accuracy of the MSAM method is assessed by comparison to the MCS method. A comparison of the MSAM with other analytical methods commonly used in construction network analysis, such as PERT and the Probabilistic Network Evaluation Technique (PNET), is also presented. The First Order Second Moment (FOSM) method, a methodology previously used solely in system reliability analysis is applied to project economics. The definition of the FOSM method is given and detailed mathematical treatments of these methods are described. The methodology of using the FOSM in construction economics is explained and ten examples are analysed using both the FOSM method and the MCS to show the applicability and the degree of accuracy of these methods. The current research shows that the MSAM method yields the probability of project completion within a prescribed target time, or the required project time at a specific probability. The research also shows that it is possible to use the FOSM methods for risk analysis in decision-making in construction economics in such areas as selection of project, elemental cost analysis, cash flow streams and setting of plant hire rates. Both methods require computational time that is significantly less than an equivalent MCS.

An integrated programme of experimental and analytical work was carried out to evaluate the nonlinear semi-rigid characteristics of timber connections using fully overlapping nails subjected to short duration lateral loading and moment. The investigation is part of a continuing programme of research at Napier University into the behaviour of timberjoints using fully overlapping nails as the connecting Z -1 mechanism. The effects of the factors and material properties that influence the behaviour of nailed joints were addressed in a structured and controlled way allowing semi-empirical models to be developed for the lateral load behaviour of rnulti-nailed timber joints using steel and plywood gusset plates. A quality control procedure was established for the testing programme and consistent standards were applied to the preparation and testing work. The semi-empirical models that were developed included for the effect of timber density: crussept late material effect- nail strength; number of nails: nail diameter; row spacing and the effect of the moisture content in the timber. They covered joints assembled with and without a gap between the timber and the gusset plates and for joints assembled with steel gusset plates, the effect of the predrill size used in the gusset plate was also investigated. The model results compared very well with the results from tests, accurately predicting the non-linear behaviour of the joints up to failure. An extensive analytical and experimental study was carried out to investigate the moment-rotation behaviour of these types ofjoints. Two linear arýd four non-linear models were developed for each type of joint and the efficiencies of the models were compared to detennine the one that best simulated the joint behaviour. The linear models consistently underestimated the capacity of the joint, giving conservative results. The best solutions were obtained by applying the torsion formula used for steel connections and incorporating the nail behaviour models developed for the non-linear lateral load joints. Account was taken of the non-linear behaviour of the connection and alternative models using fixed and moveable centres of rotation were developed. Very good comparisons were achieved between these models and the test results. A detailed comparison was made between the behaviour of the joints using the lateral load displacement models and Eurocode 5 (EC5) and it was concluded that EC5 rules did not accurately simulate the behaviour of this type of joint. It was concluded that the nail spacing rules in the code did not apply to fully overlapping nails. A limit state design method based on the principles used in EC5 has been developed from the models for the design of joints using fully overlapping nails and subjected to lateral loading or moment. The semi-rigid behaviour of the joints was also investigated and it was concluded that to safely predict the response of structures assembled with fully, overlapping nails. the semi-rigid behaviour must be included for in the analysis procedure. Rigidity factors, end fixing moment reduction factors and the secant rotational stiffness coefficients for the joints were derived. It was also shown that where the analysis was limited to the serviceability limit state. a modified elastic method of analysis could be used and where it was beyond this state a non-linear method of analysis was required.

In practice, construction firms are in business to achieve profitability. Construction companies operate in a highly competitive business environment characterised by low profit margins and high failure rates. At times firms will seek to grow in an attempt to increase profitability. At other times, firms will be concerned with survival and avoiding failure. Often firms plagued by poor performance seek to take higher risks. This may lead especially where resources exist to increased diversification. Against this background, the research focuses on the twin areas of corporate financial performance and the effects of merger activity. Prior studies in economics and accounting provide evidence that financial statement analysis can be utilised by possible investors or strategic planners to aid in the future plans and direction of the firm or to classify economic events such as mergers or failures. The present study examines the financial performance of the UK construction industry and the Global construction industry, and investigates the financial characteristics of merging construction companies. This research examines the financial performance of UK firms in different sectors of the construction industry. This analysis involves the use of descriptive statistics, which provides a valuable aid in the visual presentation of the range of the possible outcomes. In addition a probabilistic analysis of the distribution of profitability has been undertaken. This involves the use of inferential statistics which concentrates on the role of significance testing. The profitability performance of the plant hire sector was found to exceed that of contracting and materials sector. An examination of the impact of the national environment on international competitive performance and an assessment and comparison of the performance of global construction is also provided in the study. The research also investigates the financial profile of UX failed and solvent firms. The use of statistical models and accounting ratios in an effort to predict company failure for up to five years is examined. The results for the univariate analysis indicate that failing construction firms during the 1996-2001 period have low profitability and are highly geared. The testing of previous statistical failure prediction models provide little evidence of compatibility to the construction industry. The analysis on mergers and acquisition investigates the performance of construction companies involved in the acquisition process and examines the motives behind the merger process. Analysis of the relation between measures of costs and firm size in over 100 UK construction companies indicates the usefulness of scale economies. However, the evidence suggests that beyond a certain size the cost benefits appear to become exhausted. Large companies have to re-examine scale to ensure that they are employing it to their company's greater advantage. Abnormal share returns are also examined throughout a period surrounding the announcement of both successful and unsuccessful acquisition and merger bids. The overall results indicate that mergers in the construction industry create wealth for shareholders. The evidence shows significant increases in the performance of the target firms' shareholders over a 40 day event window surrounding the announcement. The results also show that bidding firms' experience no significant abnormal returns in a short period surrounding the announcement date.

In a period of rapidly growing deployment of sustainable energy sources the exploitation of solar energy systems is imperative. Colder climates like those experienced in Scotland show a good potential in addressing the thermal energy requirement of buildings; particularly for hot water derived from solar energy. The result of many years of global research on solar water heating systems has outlined the promising approach of integrated collector storage solar water heaters (ICS-SWH) in cold climates. This calls for a need to estimate the potential of ICS-SWH for the Scottish climate. This research project aims to study and analyse the performance of a newly developed ICS-SWH for Scottish weather conditions, optimise its performance, model its laboratory and field performance together with its environmental impacts and analyse its integration into buildings and benefits of such a heating system, for the primary purpose of proposing a feasible ICS-SWH prototype. Laboratory and field experiments were performed to investigate the performance of the newly developed ICS-SWH and the parameters affecting it which were fundamental to modelling its performance. This was followed by developing a thermal macro-model able to compare the temperature variation in different ICS-SWH designs; including internal temperature and external weather conditions for a given aspect ratio and to evaluate the performance of this ICS-SWH for laboratory and field conditions. This was followed by a three-dimensional Computational Fluid Dynamic (CFD) analysis of the ICS-SWH in order to optimise the fin spacing as a means of improving its performance. A Life Cycle Assessment (LCA) and monetary analysis considering the whole life energy of the different ICS-SWH designs were carried out using a previously developed thermal model in order to establish the most viable ICS-SWH with the smallest carbon footprint. Finally, a study to show how the ICS-SWH could be integrated into buildings and its potential benefits to builders and households was undertaken. Through this work, important parameters for modelling laboratory and field performance of ICS-SWH are established. The innovative modelling tool developed can predict the bulk water temperature of the ICS-SWH for any orientation and location in the world with good accuracy. Improvements of the ICS-SWH fin design were suggested through the CFD analysis while keeping the costs to a minimum. The ICS-SWH prototype showed a high commercial potential due to its environmental and monetary benefits as well as its potential for integration into commonly used solar water heating installations and modern methods of construction such as roof panels which could result in a viable commercialisation of the prototype.