L’interaction des ondes avec la microstructure des matériaux polycristallins a pour conséquence l’apparition d’un bruit dit "de structure" provenant à la fois de la diffusion simple (DS) mais aussi de la diffusion multiple (DM). L’acquisition de la matrice de transfert, K, mesurée à l’aide d’un réseau de transducteurs, a permis de mettre en évidence que les composantes DS et DM présentaient des comportements distincts. Aubry et al. ont proposé une méthode exploitant cette différence de comportement afin de séparer ces deux contributions et d'utiliser la composante DS pour imager le milieu. Cette méthode appelée MSF-DORT a été testée sur des matériaux industriels, au cours de la thèse de S. Shahjahan, et a permis de mettre en évidence son potentiel pour l'imagerie de défauts volumiques enfouis en milieu fortement diffusant. La première partie de cette thèse porte donc sur l'amélioration de MSF-DORT afin d'augmenter les performances en termes de détection de défauts et de repousser la profondeur maximale de détection de défauts volumiques. Une seconde partie aborde la possibilité d'étendre les applications de MSF-DORT à la détection de défauts dits "plans" (par opposition aux défauts volumiques) représentatifs des fissures. Cette thèse a permis de démontrer l'inefficacité de MSF-DORT pour la détection de ce type de défauts. Une troisième partie de ce travail a abouti à l'étude de la méthode FER-DORT (pour Focalisation en Emission et Réception - DORT). Cette dernière méthode présente des résultats très encourageants pour la détection de défauts plans. / The ultrasonic inspection of polycrystalline media remains a challenge. The high noise levels due to interaction between the wave and the microstructure limits the efficiency of classical ultrasonic techniques to detect a defect in a coarse grain structure. This noise comes from both single scattering (SS) and multiple scattering (MS). The acquisition of the transfer matrix, K, measured using a phased array probe, has shown that the SS and MS components have distinct behaviors. Aubry et al. proposed a method exploiting this difference in order to separate these two contributions and use the SS component for imaging the environment. This method called MSF-DORT was tested on industrial component, during the thesis of S. Shahjahan, and helped to highlight its potential for imaging bulk defects in strongly scattering medium. The first work presents in this thesis focuses on improving MSF-DORT to increase his performance in terms of defect detection and repel the maximum depth of volume defects detection. The second part deals with the possibility of extending MSF-DORT applications for the detection of known defects "planes" (as opposed to volume defects) representative cracks. This thesis has demonstrated the ineffectiveness of MSF-DORT for the detection of such defects. A third part of this work led to the study of FER-DORT method (for Focus on Making and Receiving - DORT). This last method shows very encouraging results for the detection of planes defects.

In this work, fatigue experiments and observations are used to experimentally and computationally quantify fatigue structure-property relationships and then capture these effects through a microstructure-based MultiStage Fatigue (MSF) model for a thermoplastic Acrylonitrile Butadiene Styrene copolymer. Completely reversed fatigue experiments were conducted over a range of strain amplitudes at two frequencies (1 Hz and 10 Hz). Scanning electron microscopy of fatigue fracture surfaces was used to quantify the microstructural notch root or initiating particle size for structure-property relations. Results were then processed in an MSF model sensitive to microstructural effects to capture the fatigue lifetimes for the thermoplastic ABS copolymer.

No / Multi Stage Flash (MSF) desalination plants are a sustainable source of fresh water in arid regions. Modelling plays an important role in simulation, optimisation and control of MSF processes. In this work an MSF process model is developed, using gPROMS modelling tool. Accurate estimation of Temperature Elevation (TE) due to salinity is important in developing reliable process model. Here, instead of using empirical correlations from literature, a Neural Network based correlation is used to determine the TE. This correlation is embedded in the gPROMS based process model. We obtained a good agreement between the results reported by Rosso et. al. (1996) and those predicted by our model. Effects of seawater temperature (Tseawater) and steam temperature (Tsteam) on the performance of the MSF process are also studied and reported.

Au cours des dernières années, le nombre de catastrophes naturelles a subi une augmentation effrayante partout dans le monde. Même si le nombre de décès déclarés a diminué sur les dernières années, le nombre de personnes affectées ne cesse pas d'augmenter, ayant un grand impact dans la façon dont les opérations d'aide humanitaire sont développées. L'aide humanitaire comprend une myriade d'acteurs parmi lesquels on trouve les donateurs, les agences d'aide, les organisations non-gouvernementales (ONG), les gouvernements et les prestataires de service logistique. Dans ce contexte, la logistique représente 80% des activités, et est impliquée dans les trois phases du cycle de la gestion des catastrophes. Dans l'industrie, logistique est considéré comme une source d'avantage concurrentiel, expliquant les différences de performance entre les entreprises. Pour le contexte humanitaire, la logistique a la capacité d'assurer le succès des opérations, de contribuer à la stratégie d'une organisation et permet aux bénéficiaires et aux donateurs de distinguer une ONG d'une autre. Cela est possible grâce au développement des compétences et capacités logistiques organisationnelles. L'objectif de cette thèse est donc d'identifier ces compétences et capacités logistiques organisationnelles qui peuvent assurer le succès des opérations humanitaires. À travers d'une étude de cas unique effectuée au sein de MSF Logistique, la centrale d'achat et d'approvisionnement de Médecins Sans Frontières, cette thèse fournit la preuve du rôle stratégique que la logistique joue dans les activités de l'organisation et propose un modèle de compétences et capacités logistiques pour le contexte humanitaire. / Over the past years, the number of natural disasters reported has suffered a frightening increase all around the world. Even though the number of people reported killed has decreased on the last years, the number of people reported affected has augmented having a great impact in the relief operations undertaken. Humanitarian relief comprises a myriad of actors which include donors, aid agencies, Non-Governmental Organizations (NGOs), governments and logistics providers. In this context, logistics accounts for 80% of the relief effort and is involved in all three of the disaster management phases. In industry, logistics is considered to be a source of competitive advantage, explaining the differences in performance among firms. Moving this to the humanitarian context, logistics has the capacity to ensure the success of the operations, to contribute to an organization's strategy, and allows beneficiaries and donors to distinguish an organization from another. This is only possible through the development of organizational logistics competences. The purpose of this thesis is thus to identify those organizational logistics competences and capabilities that can ensure the success of humanitarian relief operations. Through a single-embedded case study performed with MSF Logistique, the international logistics platform for Médecins Sans Frontières France, this thesis provides evidence of the strategic role that logistics plays in the organization's activities, and proposes a Logistics Capability and Competence Framework for Humanitarian Relief.

Les trois ONG humanitaires (CARE International, CRS et MSF/F) qui sont intervenues au Burundi de 1993 à 2005 ont réalisé des projets importants pour le pays. Ces acteurs transnationaux sont financés par des Etats, des Organisations internationales et des donateurs privés. C’est ainsi que l’on peut les qualifier d’acteurs intermédiaires parce qu’ils sont soumis aux contraintes étatiques et transnationales. Les financements étatiques sont motivés par la volonté de pousser les ONG humanitaires à servir des intérêts nationaux des Etats-bailleurs tandis que le financement privé légitime leur nature apolitique tout en les obligeant à se comporter comme des entreprises commerciales. Nonobstant cette nature hybride, dans chaque ONG existent des agents philanthropiques, qui travaillent juste pour l’Humanitaire. / The three humanitarian NGOs (CARE International, CRS and MSF/F) which have been operating in Burundi since 1993 to 2005 realized important projects for the country. These Transnational actors are funded by States, international organizations and private donators. That is why we can call them intermediate actors because they are submitted to governmental and transnational conditions. Static funding urges these NGOs to operate according to the national interests while private funding legitimates their transnational nature and justifies their “charity business”. Besides this hybrid nature, there are philanthropic agents in each of these three humanitarian NGOs.

Migration Stimulating Factor (MSF) is an oncofoetal protein which is constitutively produced by both epithelial and stromal cells during foetal development, not expressed by the majority of their normal adult counterparts, but re-expressed during pathological processes such as cancer and wound healing. Scotland has the highest occurrence of oral cancers in the UK; the incidence is still increasing, but patient survival remains very poor. The expression of MSF in oral tumours has not been previously reported. The aims of this study were: • To determine the effects of MSF on the migration of oral tumour cell lines and normal stromal cells in culture (chapter 3), • To ascertain the possible presence, diagnostic and prognostic value of MSF in oral squamous cell carcinoma (OSCC; chapter 4), and salivary gland tumours (SGT; chapter 5). • To identify the putative MSF receptors in oral tumour cell lines (chapter 6). For tissue culture studies, the effects of rhMSF (wild type and mutant proteins) were examined on human cell lines TYS, HSG, Endo 742 and FSF44. These cells were derived from OSCC, SGT, microvascular endothelial cells and skin fibroblasts, respectively. For ex-vivo studies, paraffin embedded archival specimens of OSCC and SGT were stained with specific MSF antibodies and the level of staining was assessed by consensus of 2-4 independent observers. The association between MSF expression and patient survival was determined by Kaplan-Meier and log-rank tests. Results presented in this thesis indicate that TYS and HSG cells secrete bioactive MSF in culture. rhMSF stimulated the migration of these tumour cells. The use of mutant proteins demonstrated marked differences among the cells examined: Five bioactive motifs (4x IGD and 1x HEEGH) were required for MSF bioactivity on TYS and HSG cells, whereas only one of these motifs was required for Endo 742 and two for FSF44. MSF+aa and MSF-aa showed the same migration-stimulating activity, but differ in their interaction with the MSF-inhibitor Neutrophil Gelatinase-Asscciated Lipocalin (NGAL). NGAL was shown to bind to and inhibit MSF+aa, but not MSF-aa. The bioactivity of MSF+aa and MSF-aa was inhibited by Insulin-like Growth Factor Binding Protein-7 (IGFBP7), MSF-function-neutralising antibody and antibody to the integrin avß3. This integrin was identified in the cell membrane material bound to MSF, suggesting that avß3 is a receptor for MSF.

This thesis investigates Médécins Sans Frontières (MSF) communication in the setting of South Sudan. More precisely, the thesis investigates MSF’s engagement in a discussion regarding the potential harm NGOs, both other and themselves, might cause in terms of conflict dynamics. The thesis takes off in the perceived conflict between the adaptation of the Hippocratic Approach, as outlined by Mary B Anderson, and the increased necessity of branding in today’s humanitarian industry and seeks to understand how this might unfold in practice. Demonstrating MSF’s commitment to ideals in line with the Hippocratic Approach, which encourage self-criticism and accountability, the thesis moves on to illustrate how branding has become an inevitable measure for NGOs to remain operational. Based on previous research identifying a successful branding as information, trust and image, where self-criticism might be counter-productive, the thesis tries to identify the conflict between the two fields. The thesis sets out to uncover some of the tensions more concretely by investigating MSF’s communication in the conflict-settings of South Sudan. It does so utilizing the method Qualitative Content Analysis. The material stems from MSF’s self-published reports, reviews and articles. In conclusion, the thesis finds that MSF does engage in a discussion about harms caused by other organizations as well as harm caused by themselves. However, the harms discussed are not put in terms of conflict dynamics in South Sudan. Furthermore, the thesis identifies some disproportion in criticism towards other organizations versus self-criticism. The thesis refrains from drawing any permanent conclusions and suggest a comparative case study to better understand the tensions in NGO’s building of a Hippocratic brand.

Yes / Multistage Flash Desalination (MSF) is currently facing an enormous challenge in cutting of the cost: within the last few years, the MSF experienced a gradual decline in investment compared to other techniques of desalting water and thus, a significant improvement is required to remain attractive for capital investors. Improved process control is a cost effective approach to energy conservation and increased process profitability. In this work, a dynamic model is presented using gPROMS model builder to optimize and control MSF process. The Proportional Integral Derivative Controller (PID) and Generic Model Control (GMC) are used successfully to control the Top Brine Temperature (TBT) and the Brine Level (BL) in the last stage at different times of the year. The objectives of this study are: firstly, to obtain optimum TBT and BL profiles for four different seasons throughout the year by minimizing the Total Seasonal Operating Cost (TSOC); secondly, to track the optimum TBT and BL profiles using PID and GMC controllers with and without the presence of constraints; thirdly, to examine how both types of controllers handle the disturbances which occur in the plant. The results are promising and show that GMC controller provides better performance over conventional PID controller to handle a nonlinear system.

Yes / Fouling on heat transfer surfaces due to scale formation is the most concerned item in thermal desalination industry. Here, a dynamic fouling model is developed and incorporated into the MSF dynamic process model to predict fouling at high temperature and high velocity. The proposed dynamic model considers the attachment and removal mechanisms in the fouling phenomena with more relaxation of the assumptions such as the density of the fouling layer and salinity of the recycle brine. While calcium sulphate might precipitate at very high temperature, only the crystallization of calcium carbonate and magnesium hydroxide are considered in this work. Though the model is applied in a 24 stages brine recycle MSF plant, only the heat recovery section (21 stages) is considered under this study. The effect of flow velocity and surface temperature are investigated. By including both diffusion and reaction mechanism in the fouling model, the results of the fouling prediction model are in good agreement with most recent studies in the literature. The deposition of magnesium hydroxide increases with the increase in surface temperature and flow velocity while calcium carbonate deposition increases with the increase in the surface temperature and decreases with the increase in the flow velocity.

Yes / Simultaneous optimisation of design and operating parameters of MSF desalination process is considered here using MINLP technique within gPROMS software. For a fixed fresh water demand throughout the year and with seasonal variation of seawater temperature, the external heat input (a measure of operating cost) to the process is minimised. It is observed that seasonal variation in seawater temperature results in significant variation in design with minimum variation in operating conditions in terms of process temperatures. The results also reveal the possibility of designing stand-alone flash stages which would offer flexible scheduling in terms of the connection of various units (to build up the process) and efficient maintenance of the units throughout the year as the weather condition changes. In addition, operation at low temperatures throughout the year will reduce design and operating costs in terms of low temperature materials of construction and reduced amount of antiscaling and anti-corrosion agents.