Craton cores far from plate boundaries have traditionally been viewed as stable features that experience minimal vertical motion over 100-1000Ma time scales. Here we show that the Fennoscandian Shield in southeastern Sweden experienced several episodes of burial and exhumation from similar to 1800Ma to the present. Apatite, titanite, and zircon (U-Th)/He ages from surface samples and drill cores constrain the long-term, low-temperature history of the Laxemar region. Single grain titanite and zircon (U-Th)/He ages are negatively correlated (104-838Ma for zircon and 160-945Ma for titanite) with effective uranium (eU=U+0.235xTh), a measurement proportional to radiation damage. Apatite ages are 102-258Ma and are positively correlated with eU. These correlations are interpreted with damage-diffusivity models, and the modeled zircon He age-eU correlations constrain multiple episodes of heating and cooling from 1800Ma to the present, which we interpret in the context of foreland basin systems related to the Neoproterozoic Sveconorwegian and Paleozoic Caledonian orogens. Inverse time-temperature models constrain an average burial temperature of similar to 217 degrees C during the Sveconorwegian, achieved between 944Ma and 851Ma, and similar to 154 degrees C during the Caledonian, achieved between 366Ma and 224Ma. Subsequent cooling to near-surface temperatures in both cases could be related to long-term exhumation caused by either postorogenic collapse or mantle dynamics related to the final assembly of Rodinia and Pangaea. Our titanite He age-eU correlations cannot currently be interpreted in the same fashion; however, this study represents one of the first examples of a damage-diffusivity relationship in this system, which deserves further research attention.

La Broncho-Pneumopathie Chronique Obstructive (BPCO) est une pathologie inflammatoire chronique caractérisée par une détérioration irréversible des voies aériennes et des espaces alvéolaires. L'emphysème est la composante principale de la BPCO et l'exposition à la fumée de cigarette en est le principal facteur étiologique. La réponse inflammatoire au cours de la BPCO est caractérisée par une infiltration massive du tissu respiratoire par les cellules inflammatoires qui sécrètent de nombreuses protéases. Ces protéases participent à la dégradation des composants de la matrice extracellulaire et en particulier à la dégradation de l'élastine. Cette dégradation conduit à la genèse de peptides solubles d'élastine (PE) retrouvés dans les différents liquides biologiques de patients BPCO. Si les lymphocytes T CD4+ et les PE sont décrits dans la littérature comme impliqués dans la physiopathologie de la BPCO, en revanche, l'impact de leur interaction sur la polarisation Th reste à élucider. Le travail réalisé au cours de cette thèse a permis de mettre en évidence une polarisation de la réponse lymphocytaire T vers un profil de type Th1 et Th17 au cours de l'emphysème murin induit par le peptide d'élastine VGVAPG. Cette polarisation est dépendante de l'interaction du VGVAPG avec son récepteur spécifique à la surface des lymphocytes T, et est inhibée en présence d'analogues antagonistes du récepteur à l'élastine. Ces résultats permettent d'envisager l'utilisation de tels antagonistes comme des agents pharmacologiques régulant les effets délétères pro-inflammatoires de la réponse T helper au cours de la BPCO. / Chronic Obstructive Pulmonary Disease (COPD) is a chronic inflammatory disease characterized by irreversible damage to airways and alveolar spaces. Emphysema is the main component of COPD and exposure to tobacco smoke is the main etiological factor. The inflammatory response in COPD is characterized by a massive infiltration of respiratory tissue by inflammatory cells that secrete many proteases. These proteases participate in the degradation of extracellular matrix components and particularly in elastin degradation. This elastin breakdown leads to the genesis of soluble elastin peptides (EP) found in various biological fluids of COPD patients. If CD4+ T cells and EP are described in the literature as being involved in the pathophysiology of COPD, consequence of their interaction on the T helper polarization remains to elucidate. The work done during this thesis allowed highlighting the polarization of T cell response towards a Th1 and Th-17 profile during VGVAPG-induced murine emphysema. This polarization, which is dependent of the VGVAPG interaction with its specific receptor expressed on T cells, is inhibited using analogous antagonist elastin receptor peptides. These results allowed us to envisage such antagonist peptides as pharmacological agents that regulate the deleterious pro-inflammatory effects of the T helper cell response during COPD.

Low energy building methods, and the corresponding economic and environmental aspects, are an important area of consideration in many developed countries. Saudi Arabia characterized by its hot climates and geographical location in a global region renowned for its high energy consumption and carbon emission rates. Consequently, this research aims to foster the development of low energy housing in Saudi Arabia and establish a low carbon domestic design framework for Saudi Arabia that takes into account the local climatic conditions, context and socio-cultural challenges. In order to fulfil the above stated aims, this research establishes a definition system for low energy consumption in kWh/m² for the Saudi Arabian climate. To achieve the aims stated above, a comprehensive, four stage study has been performed. This investigation has attempted to: (a) identify factors resulting in high energy consumption in domestic buildings in Saudi Arabia; (b) identify the weaknesses of housing design in terms of architectural layouts and mass, house envelope design and construction materials used, and on-site renewable energy strategies; (c) establish and develop a low carbon domestic design framework that supports architects, civil engineers and building professionals in the design of sustainable homes for the Saudi Arabian climate, context and cultural requirements; and (d) propose three different, viable housing prototypes employing the established framework, thereby validating that framework through the identification of their energy consumption levels. Each stage of this research utilizes a specific methodology: public survey analysis; site visits and modeling analysis; expert consultation, using the Delphi technique approach; and the validation analysis approach. This study contributes to the body of knowledge within this field by offering a low carbon domestic framework for the design of low energy homes in Saudi Arabia. These findings are broadly applicable to other regions with similar climatic conditions and cultural requirements, such as those in the Middle East and GCC countries. The findings suggest that an energy reduction of up to 71.6 % is possible. Therefore, the system for low energy consumption level standards is suggested as a range between 77 kWh/m² and 98 kWh/m². The comprehensive economic and environmental benefits of these reductions have been analysed and benchmarked against the current situation in selected developed countries.

For reinforced concrete structures subjected to chlorides, carbon dioxide laden and other aggressive environments, corrosion of the reinforcing steel is seen as a global problem. Maintenance and repairs resulting primarily from premature concrete cracking and spalling have an estimated cost running to $100 billion per annum world-wide. The continual demands for greater load carrying capacity of existing infrastructure only exacerbate the problem. In practice, concrete crack width propagation is seen as one of the most important criteria for design and assessment of the long term serviceability of concrete structures. It is therefore economically beneficial to have a fundamental understanding of the growth of the crack width over time so that better informed decisions can be made regarding the carrying out of any repairs. This research attempts to examine the process of concrete cracking and determine the surface crack width of concrete structures under the combined effects of reinforcement corrosion and applied load in both an analytical and numerical manner. In the analytical method, a model for stiffness reduction of cracked concrete has been derived based on the concept of fracture energy and an analytical solution has been obtained. In the numerical method, an interfacial element has been developed to predict concrete crack width under combined effects based on a cohesive crack model in conjunction with finite element codes. To help accurate prediction of crack width in the numerical method, a realistic constitutive relationship for concrete under direct tension has been obtained from the laboratory experiments. It is concluded in this thesis that both the analytical and numerical methods are one of very few available theoretical methods that can predict with reasonable accuracy concrete crack width of reinforced concrete structures under the combined effects of reinforcement corrosion and applied load. This research focuses on concrete cracking caused by reinforcement corrosion and applied load without considering other factors, e.g., weathering, freeze-thaw and chemical attack. Both methods can be used as a tool to assess the serviceability of corrosion affected concrete infrastructure if reinforcement corrosion and applied load are the main causal factors of concrete cracking. For this type of concrete structures, therefore, scientific information can be provided for asset managers in decision making regarding possible interventions. Timely interventions have the potential to prolong the service life of reinforced concrete structures.

Future energy supply infrastructure schemes for the built environment are set to consist of a diverse mix of distributed generation technologies, increasingly stringent local emissions reduction targets, and potentially complex ownership structures. This thesis presents a new modelling method that integrates technical design, green house gas emissions analysis and financial analysis models for new build multi energy vector systems. The model was used to compare and characterise several alternative heating technology options for the carbon constrained design of a generic UK market town residential development. Of the options examined, natural gas combined heat and power based district heating was shown to provide the least cost solution for projects built before 2020. Beyond 2025, electric heat pumps provided the cheapest option in response to the decarbonisation of the grid supplied electricity. The integrated model was used as the basis of an optimised infrastructure design tool. This was applied to determine the least cost energy supply technology mix for a new build community redevelopment scheme at Ebbw Vale, South Wales. It was shown that both the optimal design and corresponding optimal cost is dependent upon the year of build completion for the project and the

The construction industry has been facing immense challenges to move towards more- sustainable buildings with minimum harm to the environment. The building design and construction process is conditioned by numerous sustainability regulations and assessment measures, to promote sustainable construction. These regulations are continuously expanding in their requirements, and incorporating a huge amount of data that needs to be rigorously dealt with, in order to check compliance and asses the performance Building Information Modelling (BIM) promotes the effective information and process integration across the building life-cycle and supply chain. This integration should comply with an increasingly-complex regulatory environment and statutory requirements. The aim of this thesis is to improve and facilitate the sustainability compliance checking process, by focusing on inter-operability between existing methods of compliance checking and building information modelling. This thesis presents a generic approach for BIM based compliance checking against standards and regulations, with a particular focus on sustainable design and procurement. To achieve this, a methodology has been developed to enable automated sustainability compliance checking. This involves (a) extracting regulatory requirements from sustainability-related regulations available in textual format; (b) converting these into BIM- compatible rules; (c) processing these rules through a dedicated rule-based service; and (d) performing regulatory compliance analysis underpinned by the concept of BIM. A semantic extension of the IFC (Industrial Foundation Classes) for sustainability compliance checking has been developed. The outcome of the research was implemented in the RegBIM project and is in the process of being exploited as an online service by industrial organization, the Building Research Establishment (BRE) in the UK.

Thesis advisor: Jeremy D. Shakun / Arctic permafrost contains a substantial stock of carbon that could be released to the atmosphere as CH4 and CO2 upon thawing, making it a potentially powerful amplifier of future warming. The sensitivity of permafrost to climate change is uncertain, however, and occurs on time scales longer than those captured by the instrumental record. Speleothems – cave precipitates deposited from flowing or dripping water – in currently frozen regions record past episodes of thaw, which can be used to assess the response of permafrost to long-term warmth. Here, we present 90 uranium-thorium ages on speleothems from across the North American Arctic, sub-Arctic and northern alpine regions to reconstruct a 600-kyr permafrost history. Widespread speleothem growth supports an episode of extensive permafrost thaw during the Marine Isotope Stage 11 interglacial about 400 ka, when global temperature was only slightly warmer than pre-industrial conditions. Additional growth is evident during MIS 13, curiously, a smaller magnitude interglacial. Ice-core records of atmospheric greenhouse gases do not show elevated concentrations at these times, perhaps suggesting that the permafrost carbon pool was smaller than today or released gradually enough to be buffered by other reservoirs. / Thesis (MS) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

Cold formed steel (CFS) sigma sections are commonly used as purlins in the construction of modern industrial and residential buildings due to their excellent strength-to-weight ratio. This thesis reports investigations on the structural behaviour of CFS sigma purlins in three different parts of modern roof systems. In the first investigation, the pre-buckling, buckling, post-buckling and post-failure behaviour of continuous CFS sigma purlins near internal supports was studied by experimental and numerical methods. In the second investigation, the moment-rotation response as well as the moment resistance of the sleeve connection of sigma purlins was studied by laboratory tests. Engineering models were developed to predict the behaviour of this connection and a good correlation was observed with the experimental data. In the third investigation, the flexural stiffness and moment resistance of CFS sigma purlins fastened to roof sheeting with large screw spacing was studied experimentally. The purlin-sheeting assemblies were subjected to both downward and uplift loadings, from which different behavioural aspects such as flexural stiffness, failure modes and ultimate load were examined. Test results are utilized to develop design proposals for sigma purlins that codes or standards have not yet covered.

Lessons learnt from the construction industry have proved that knowledge management (KM) can enhance construction projects successfully. The existing KM models and tools may have some problems, which cannot be used efficiently and effectively. This research aims to develop a new KM model that overcomes such problems and provides an effective way for managing knowledge in the construction industry. An extensive review and analysis of KM models has been carried out and a KM model was developed to fill the gaps of previous KM models. Interviews with KM practitioners and a questionnaire survey have been conducted to enhance the KM model. A final KM model has been set to provide an effective solution for successful implementation and application of KM in construction projects. Two case studies in the construction industry have been carried out to evaluate the applicability and validity of the proposed KM model and how it can be used to improve existing KM systems. The results indicated that the proposed model can effectively facilitate the implementation and application of KM in the construction organisations. Recommendations are given to improve the future implementation and application of KM in construction projects.

The supply of adequate and affordable houses is still a big challenge in many developing countries. Governments have sought to use different housing strategies, such as public private partnerships (PPPs), to solve these urban housing problems, but with limited success. The aim of this study is, firstly, to examine the challenges affecting the delivery of HPPP projects in developing countries and, secondly, to propose a PPP conceptual model to address the identified challenges. A mixed-methods approach was used to collect data from various stakeholders involved with housing public private partnership (HPPP) projects. Purposive sampling was used to select the targeted respondents. The quantitative data were analysed through the Statistical Package for the Social Sciences (SPSS 22.0) whereas the qualitative data were analysed by content analysis. This study identified several challenges hindering the success of HPPP projects with the highest ranked challenge found to be: inadequate PPP skills and knowledge. Results demonstrate that PPP can be adopted as an alternative approach; however; the identified challenges need to be addressed for a successful outcome to be achieved. The key contributions to knowledge include: bridging the literature gap as this study is the first that identifies and ranks the HPPP challenges within the developing country context. Additionally, a conceptual model has been developed by adopting (and modifying as appropriate) success factors from international best practice. It is anticipated that the proposed conceptual model, validated by PPP experts, will provide a valuable road map for the successful delivery of HPPP projects in developing countries.