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In recent years, aircraft manufacturers have been making progress in the design of more efficient aircrafts to reduce the environmental footprint. To attain this target, aircrafts manufactures work on the replacement of the hydraulic and bleed systems for electrical systems leading to a “More Electrical Aircraft”. However, the expected mass gain is a challenge, as previous technologies have been developed and optimized for decades. The new electrical solutions need to be look into detail to be competitive with previous technologies. All degrees of freedom must be considered, that is, new technologies and architectures. In particular, an HVDC network that reduces the number of rectifier stages seems a promising solution. From the HVDC network, the different three phase AC loads will be supplied by a series of power generic inverters. As the power consumption of the different loads change during the flight mission, the same inverter is used to supply different loads. The connection between the inverters and the loads is managed by a matrix of contactors. The proposed solution also considers redundant configurations, thus increasing system robustness. The design of the innovative system is presented in this document. That is, determining the optimal trade-off between the number of power inverters and the nominal power of each generic inverter that will also impact the size of the matrix of contactors. However, to assess the combinatory problem, the mass of the different components as a function of the nominal power needs to be calculated. A design environment is therefore created to perform automatic and optimized design of power converters. The different components are described using a “direct modelling” approach and coded using “object-oriented” programming. The components are validated experimentally or by numerical simulations. The different models are coupled to an optimization environment and to a frequency solver allowing a fast calculation of the steady-state waveforms. The optimization environment performs the precise design of the different parts of the power inverter: heatsink, power module, DC filter and coupling inductor. The power inverter is designed for different values of nominal power and switching frequency. The optimization assesses as well the usage of different technologies. Finally, the results are used to determine the optimal trade-off between the number of inverters and the nominal power of each inverter using a heuristic algorithm.

Public-private partnerships (P3s) are increasingly used in jurisdictions across Canada to deliver public infrastructure and services. The need for new or redeveloped hospital infrastructure in particular has made this a leading avenue for P3 proliferation. The objective of this study is to analyze P3 policy and projects, principally in relation to the BC and Ontario provincial health sectors. The central arguments made are threefold: P3s are a unique form of accumulation by dispossession and public sector marketization; P3 projects are intrinsically unable to meet the promises made by proponents and carry several other negative social consequences beyond this; and P3 policy, though rooted in normative ideological assumptions and aspirations, is being normalized in BC and Ontario through the establishment of P3 enabling fields over the past decade. The concept of an ‘enabling field’ captures a constellation of new arrangements, notably capital planning procedures and legislative frameworks, supportive secondary reforms, and greater institutional support for privatization. Together these elements help routinize, institutionalize, and depoliticize P3 policy. Canada’s pioneering full spectrum P3 hospitals (where the private partner is charged with designing, building, operating, and financing the facility) are examined in detail: in BC, the Abbotsford Regional Hospital and Cancer Centre and the Gordon and Leslie Diamond Health Care Centre; and in Ontario, the Brampton Civic Hospital and the Royal Ottawa Hospital. These cases reveal the troubling results that policy normalization ignores: poor value for money and inadequate risk transfer, misleading claims of ‘on time and on budget’ delivery, an erosion of service quality and working conditions, and opaque partnership agreements that offer little by way of accountability and transparency. These findings challenge the assumptions and rhetoric of P3 proponents, and offer different examples of how dispossession and marketization manifest in the public health care system.

Cette thèse est consacrée à l'étude des processus stochastiques décentralisés. Parmi les exemples typiques de ces processus figurent la dynamique météorologique, la circulation automobile, la façon dont nous rencontrons nos amis, etc. Dans cette thèse, nous exploitons une large palette d'outils probabilistes permettant d'analyser des chaînes de Markov afin d'étudier un large éventail de ces processus distribués : modèle des feux de forêt (réseaux sociaux), balls-into-bins avec suppression, et des dynamiques et protocoles de consensus fondamentaux tels que Voter Model, 2-Choices, et 3-Majority. This thesis is devoted to the study of stochastic decentralized processes. Typical examples in the real world include the dynamics of weather and temperature, of traffic, the way we meet our friends, etc. We take the rich tool set from probability theoryfor the analysis of Markov Chains and employ it to study a wide range of such distributed processes: Forest Fire Model (social networks), Balls-into-Bins with Deleting Bins, and fundamental consensus dynamics and protocols such as the Voter Model, 2-Choices, and 3-Majority.

This thesis focuses on possible platforms for a bottom-up approach towards realizing and characterizing atomically assembled magnetic and electronic artificial lattices. For this, we make use of the scanning tunneling microscope (STM), which provides a local probe of the magnetic and electronic properties of the sample and allows for the atom-by-atom construction of extended lattices. On the one hand, to address avenues for constructing extended spin lattices, we study single Fe atoms coordinated on the four-fold symmetric nitrogen binding site of the Cu2N/Cu3Au surface—a system which permits large-scale atomic assembly, and allows for independent access to both the orbital and spin degrees of freedom. On the other hand, we investigate the viability of laterally confined vacuum resonances on the chlorinated Cu(100) surface as a basis for constructing electronic lattices. We atomically assemble dimers and trimers of various geometries to determine the tight-binding parameters, and as a proof of concept, experimentally realize a looped Su-Schrieffer–Heeger chain using this platform. These studies are made possible by means of a low-temperature, ultra-high vacuum STM, which allows for atom manipulation and, via spectroscopic techniques, permits us to locally probe the sample density of states and detect inelastic excitations of the spin and orbital angular momentum.

The world’s population is increasing rapidly as a result of reduced child mortality and extended lifespan. However, the elderly of today are not healthier than their parents at the same age. As a result of excessive food intake, physical inactivity and a decline of metabolic flexibility, over 70% of all elderly suffer from at least one chronic disease, such as diabetes. While the mechanisms behind ageing-induced metabolic decline are still poorly understood, several anti-ageing strategies are currently under investigation for their potential to improve metabolic health. In this thesis, we investigated the effectiveness of several anti-ageing strategies when implemented at an advanced age. Recently, fibroblast growth factors (FGFs) have gained interest as a pharmacological intervention for the treatment of metabolic diseases. Administration of FGF21 or FGF19 successfully reduces symptoms of liver diseases, but could not induced anti-diabetic effects. Using a hepatocyte cell model, this thesis investigated the signalling mechanisms involved after administration of FGF21 and different FGF1-analogues. Furthermore, dietary interventions, such as caloric and protein restriction, have a large impact on metabolic health and flexibility. This thesis highlights the significant improvements in glucose and energy homeostasis of aged mice after these dietary interventions. However, when administrated with a high fat diet, the metabolic flexibility, which allow young mice to compensate, is reduced in aged mice, thereby contributing to the development of metabolic syndrome. Overall, this thesis contributes to the idea that the importance of nutritional quality at advanced ages increases to maintain metabolic health.