Exposure to a strong T-helper 2 (Th2)-like environment during fetal development may promote allergy development. Increased cord blood (CB) levels of the Th2-associated chemokine CCL22 were associated with allergy development during the first 2 y of life. The aim of the present study was to determine whether CB Th1- and Th2-associated chemokine levels are associated with allergy development during the first 6 y of life, allowing assessment of respiratory allergic symptoms usually developing in this period. The CB levels of cytokines, chemokines, and total IgE were determined in 56 children of 20 women with allergic symptoms and 36 women without allergic symptoms. Total IgE and allergen-specific IgE antibody levels were quantified at 6, 12, 24 mo, and 6 y of age. Increased CB CCL22 levels were associated with development of allergic sensitization and asthma and increased CCL17 levels with development of allergic symptoms, including asthma. Sensitized children with allergic symptoms showed higher CB CCL17 and CCL22 levels and higher ratios between these Th2-associated chemokines and the Th1-associated chemokine CXCL10 than nonsensitized children without allergic symptoms. A pronounced Th2 deviation at birth, reflected by increased CB CCL17 and CCL22 levels, and increased CCL22/CXCL10 and CCL17/CXCL10 ratios might promote allergy development later in life.

Pendant ma th ese, j'ai eu la chance d'apprendre et de travailler sous la supervision de mon directeur de th ese R emi, et ce dans deux domaines qui me sont particuli erement chers. Je veux parler de la Th eorie des Bandits et du Compressed Sensing. Je les vois comme intimement li es non par les m ethodes mais par leur objectif commun: l' echantillonnage optimal de l'espace. Tous deux sont centr es sur les mani eres d' echantillonner l'espace e cacement : la Th eorie des Bandits en petite dimension et le Compressed Sensing en grande dimension. Dans cette dissertation, je pr esente la plupart des travaux que mes co-auteurs et moi-m^eme avons ecrit durant les trois ann ees qu'a dur e ma th ese.

The aim of this study is to investigate the physical and mechanical properties of construction materials in relation with the structural behaviour of a historic structure. Within this framework, the brick masonry superstructure of Tahir ile Zuhre Mescidi, a XIIIth century Seljuk monument in Konya was selected as case study. The study started with the determination of the basic physical (bulk density, effective porosity, water absorption capacity), mechanical (modulus of elasticity, uniaxial compressive strength), durability and pozzolanic properties of original brick and mortar by laboratory analysis. The obtained data was utilized as material information at the modelling of superstructure, by means of structural analysis software, SAP2000. At the modelling stage, finite element method was used and the complexity of masonry in terms of nonlinearity and heterogeneity was taken into account within practical limits. The constructed model was investigated under dead load, wind load, snow load, temperature load and earthquake load and their possible combinations. Structural investigation was continued with two scenarios representing possible wrong interventions i.e. completion of the partially collapsed superstructure with concrete and the concrete coating over superstructure. These cases were investigated under uniform and randomly distributed temperature loads. The results approved the safety of the superstructure under normal service conditions, defined as the appropriate combinations of dead load, snow load, wind load and temperature load. The structure appeared to be safe under the earthquake load too. The analyses carried out to simulate the inappropriate restoration works demonstrated the structural damage formations at the original structure.

The compatibility properties of some contemporary finish coats together with their complementary layers used in insulated exterior walls were examined in terms of water vapour permeability and modulus of elasticity. Basic physical and mechanical properties of some synthetic-, cement- and polymer-based external finish coats were analyzed in laboratory. Some additional samples, complementing the wall section, were also examined for their water vapour permeability. Results showed that the finish coats were high vapour permeable although they had high resistance to water vapour permeation, which was achieved by their application in thin layers. Cement-based undercoats were found to be medium permeable. The application of primer and/or paint was found to decrease the permeability of finish coats in different ranges. Thermal insulation layer was found to interrupt water vapour flow considerably. Among polystyrene- and mineral-wool-based thermal insulation boards, rockwool was recommended as the insulation layer due to its medium vapour permeability. In conclusion, walls insulated externally with rockwool boards and plastered with polymer-based finish coat, FC8ACB or synthetic-based finish coat FC3SB were found to be the most proper combination in terms of breathing and thermal resistance capabilities. All finish coats seemed to have sufficient strength and except the synthetic-based finish coat, FC2SB, they seemed to be compatible with each other and with the masonry in terms of their Emod values. Further studies were recommended on some other compatibility properties of finishing systems, such as thermal and moisture dilatation properties, and on the relation between the resistance to water vapour permeation and water permeability.

This thesis offers a comprehensive risk assessment methodology that provides a decision support tool, directed for Turkish construction organizations, which can be utilized through the bidding decisions for international construction projects. Within this context the analytic network process technique is implemented to develop a risk assessment model, which is used to derive the relative priorities of the risk factors associated with international construction projects. The findings of the risk assessment model have demonstrated that the most significant sources of risk are vagueness of contract conditions about risk allocation, client, and immaturity of legal system in the host country. Factors such as low % of advance payment, geographical distance, and bribery were found to be relatively insignificant. An international construction project risk rating software application is then developed. The application incorporates the derived priorities from the risk assessment model to calculate a risk rating for a given international construction project. To increase the credibility of the results a risk rating adjustment methodology was integrated into the application. Its purpose is to count for the potential influencing factors that may increase the risk level of a given project. The influencing factors which were considered are the company&rsquo / s experience, contract type, level of the available project data from the outset, and project delivery system. The application is also structured to enhance the organizational learning practices. It improves the process of the organizational memory formation with respect to postproject risk data by developing a database of risk information of the rated projects for future references. The reliability of the application was tested with post-projects risk data and was found to be satisfactory.

One of the major change efforts for the construction industry is lean construction. This thesis analyzes the practices of the construction companies in Turkey from the lean construction perspective. Prior to the analysis in question, requisite information about change in the construction industry, lean thinking and lean construction will be presented. A questionnaire, based on a lean construction model, is used to survey the practices and gather the data for the analysis. Various statistical analysis methods are performed on the gathered data to make inferences. According to these analyses, the lean construction characteristics of the construction companies will be discussed and the recommendations for improving the lean conformance of the construction companies will be presented.

In this study, energy conservation potential of appropriate passive cooling and basic heat avoidance strategies were investigated for hot and humid climates. Within this framework, thermal behavior of a case study building that is situated in Cyprus was assessed by collecting temperature and relative humidity data from various rooms of the building during certain days in August. Then, by using feasible simulation strategies of the software tool Summer-Building, the effectiveness of passive cooling measures in reducing energy consumption were examined, for summer months. In this context, the case study building was re-evaluated by applying natural ventilation, night ventilation and ground cooling strategies as well as solar control and shading devices as overhangs and side fins. Consequently, based on the results of the evaluation model, it was found that the proposed passive cooling strategies and basic heat avoidance concepts could provide more than 50 % energy conservation, relative to the completely air conditioned reference building, between 1-15 August 2007.

ABSTRACT EFFECTS OF POZZOLAN INCORPORATION AND CURING CONDITIONS ON STRENGTH AND WATER RESISTANCE OF NATURAL GYPSUM PASTES Cengiz, Okan Ph.D., Department of Civil Engineering Supervisor : Prof. Dr. Turhan Y. Erdogan September 2009, 189 pages There are large reserves of gypsum rock (CaSO4&middot / 2H2O) in Turkey and in various regions of the world. Heating gypsum rock to 140 - 190 0C causes it to lose three-fourths of its water molecules and turn into gypsum, called plaster of Paris / heat application over 190 0C results in loss of all the water molecules and this form of the material is called gypsum anhydrite. When gypsum is mixed with water, it gains cementitious property and hardens in a short time. Therefore, natural gypsum anhydrite and especially plaster of Paris are widely used in the construction industry. On the other hand, its not being water resistant and having low strength restrict the use of gypsum products for outdoor applications. In this study, the effects of pozzolan incorporation to natural gypsum pastes and application of various curing regimes for improving their water resistance and strength were investigated. Compressive strength and absorption tests on one thousand one hundred twenty two 5-cm cube specimens produced from v 13 different mixture types were conducted. Also the microstructures of these products were investigated using the analytical technique X-Ray Diffraction. The test results showed that water resistance and strength properties of pozzolan-incorporated gypsum products were improved. Curing of the product at elevated temperature regimes was an additional factor that contributed to this improvement. It was concluded that the natural gypsum mixtures prepared and cured at the above-mentioned conditions could also be used for outdoor applications. Keywords: Pozzolan, Natural Gypsum, Elevated Temperature Curing

Accelerating and mineral admixtures, one of the major ingredients in concrete, are primarily used to modify the properties of both fresh and hardened concrete. Within the scope of this thesis, there were four types of cements having almost identical fineness. The mixes were prepared by using natural pozzolan, blast furnace slag and limestone conforming to TS EN 197-1 and two types of accelerating admixtures, namely triethanolamine (TEA) and calcium formate (CF). The effect of set accelerating admixtures with different cement types on the setting time, water demand and compressive strength has been analyzed by an experimental study in accordance with relevant ASTM standards. Finally, it has been observed that the amount of the accelerating admixtures used is suitable because of their effects on the water demand, setting and strength. Due to the density difference of mineral admixtures and clinker, the normal consistency and 110% flow water content should be considered on a volumetric basis. The effectiveness of the accelerating admixtures on the normal consistency water, 110% flow water content and setting time depends on the type and amount of mineral admixtures. The increase caused by CF in the normal consistency and 110% flow water content is higher than that by TEA. The accelerating effect of TEA and CF on the setting times is more significant for cements incorporating 6% mineral admixture. The effects of accelerating admixtures on the compressive strength change with specimen age, type and amount of mineral admixtures. Generally, for all cement types, early age compressive strengths increase with the increase of TEA, however long term strengths increase by increasing CF.

Due to its complex nature, risk and uncertainty are more widespread in construction industry than many other industries. Aiming to ensure that all project objectives are met, risk management is considered as a critical success factor for construction projects. The core elements of risk management are now known and used by many organizations. On the other hand, as declared by Project Management Institute (PMI), the ability to measure the effectiveness in managing risk is one of the most important areas that risk management needs to be developed in. Designed to assess the capability of a project or an organization in a particular area, a maturity model aids in determining strengths and weaknesses, and to target improvement strategies accordingly. Several maturity models have been developed for the area of risk management and furthermore, an attempt to adapt a generic risk management maturity model to the construction industry was specified from the literature. All in all, when examined, it was seen that most of these models outline the topics to be investigated in a maturity assessment and provide guidance in terms of content. It was believed that a practical approach was needed and the diagnostic characteristics of these models should be enhanced. Therefore, the aim of this study was to propose a construction risk management maturity framework, together with an easily applicable and effective questionnaire. To achieve this aim, six outstanding risk management maturity models were examined, and the proposed model was further supported with construction-specific attributes such as construction supply chain issues. The applicability of the model was tested through case studies conducted with five large scale Turkish construction companies. The results were evaluated and interpreted for each company and the gathered data were further investigated through statistical tests for certain comparisons. Finally, the questionnaire was revised with respect to the feedback received from the case studies.