L'hydrogène… Cet élément simple et très abondant pourrait être un contributeur clé à la transition énergétique, mais dans quelles conditions technico-économiques et politiques ? Cette thèse propose une contribution à l'évaluation de la faisabilité de pénétration de l'hydrogène dans le système énergétique, en mettant en oeuvre différents modèles qui permettent des éclairages complémentaires. Elle se concentre sur l’hydrogène bas carbone, obtenu par électrolyse de l’eau.Notre analyse multirégionale qui porte sur le contexte énergétique européen, américain, chinois et japonais (régions qui présentent des défis énergétiques contrastés) montre que les politiques énergétiques actuelles ne facilitent qu’une faible pénétration de l'hydrogène dans le système énergétique, lui permettant de réaliser environ 3% de l’effort à fournir par les quatre régions afin de limiter l’augmentation de la température à 2°C par rapport aux niveaux préindustriels. Nous soulignons dans cette thèse que l’injection d’hydrogène dans les réseaux de gaz naturel qui permet dans une certaine mesure d’éviter des fuites de méthane à fort pouvoir de réchauffement, pourrait jouer un rôle significatif dans la réalisation des objectifs de réduction des émissions de gaz à effet de serre.L'analyse des marchés de l'hydrogène a été menée en deux étapes. Tout d'abord, chaque marché (industriel ou énergétique) a été abordé individuellement afin d’établir des coûts d'entrée sur ce marché (pour les différents contextes énergétiques considérés). Ensuite, les différentes applications de l’hydrogène ont été resituées en interaction avec l’ensemble du système énergétique à travers le modèle TIMES-PT et un cas d’étude portant sur le Portugal, permettant ainsi d’examiner le potentiel de couplage entre les secteurs énergétiques rendu possible par l’hydrogène. Ces travaux ont permis de qualifier l'attractivité des différents marchés, celui de la mobilité apparaissant comme le plus favorable.Nous nous sommes ensuite intéressés aux coûts requis sur l'ensemble de la chaîne d'approvisionnement en hydrogène afin de pénétrer le marché de la mobilité.Pour ce faire, nous avons utilisé des modèles avec une maille géographique et temporelle fine (GLAES, EuroPower et InfraGis), en commençant par l’étape de production. Nous avons étudié le rôle potentiel de l'hydrogène pour la fourniture de flexibilité au système électrique dans un contexte de forte pénétration des énergies renouvelables intermittentes en France. Nos résultats montrent que l’hydrogène pourrait permettre non seulement d’éviter d’écrêter la production d’énergies renouvelables (entre 1,4 et 7,9 TWh en fonction du scénario de capacité d’interconnexion), mais pourrait aussi mettre à profit l’énergie nucléaire disponible (bas carbone donc), évitant par-là d’imposer de fortes rampes de puissances aux centrales. Cependant, une attention particulière doit être accordée au taux d'utilisation de l'électrolyseur afin de maintenir les coûts de production d'hydrogène suffisamment bas.Enfin, nous nous sommes concentrés sur l’approvisionnement de l’hydrogène, depuis les sites de production jusqu’à l’utilisation pour la mobilité, la question de l’infrastructure étant un problème majeur entravant les investissements dans l’hydrogène. Cinq filières d’approvisionnement (transport et distribution) ont été développées à la maille régionale et comparées sur le plan économique pour le cas français. Nos résultats montrent que, lors des toutes premières phases de pénétration du marché (scénario 1%), il est plus intéressant de privilégier la production décentralisée. / Hydrogen… This simple, very abundant element holds great promise to contribute to the transition towards a cleaner future energy system, but under which techno-economic and political conditions? This thesis is a contribution to the assessment of the hydrogen penetration feasibility into the energy system, using a multi-model approach. The focus is put on low-carbon hydrogen, obtained by electrolysis.Our multi-regional analysis on the European, American, Chinese and Japanese energy context (presenting contrasted energy challenges) show that, with the current energy policies implemented which result in a modest penetration of hydrogen into the energy system, hydrogen may achieve approximately 3% of the effort that needs to be done by the four regions, in order to limit the increase of the temperature to 2°C, compared to preindustrial levels. We highlight in this thesis that blending hydrogen with natural gas, and thereby avoiding methane leakages to a certain extent, may represent a significant contribution in achieving the carbon mitigation goals.The hydrogen market analysis has been carried out following two steps. First, each market (industrial and energy-related) was tackled aside in order to propose market entry costs considering the four energy contexts and investigate the timeframe of the market penetration potential. Then, the different hydrogen applications were examined within the overall energy system through the TIMES-PT model (for a Portugal case study), allowing to investigate the hydrogen potential for energy sector coupling. Based on this work, the markets attractiveness was evaluated: mobility (using fuel cell vehicles) appears to be the most favourable.Then, we tackled the required costs over the whole hydrogen supply chain in order to enter the mobility market.To do so, we used temporally and spatially resolved models (GLAES, EuroPower and InfraGis) starting with the production side where we studied the hydrogen potential role in providing the electricity system with flexibility and the impact of such electrolysis operation on the hydrogen generation costs in the context of high shares of renewable energies in France. Our results show that hydrogen can contribute to improve the flexibility of the electric system by allowing avoiding renewable curtailment (between 1.4 and 7.9 TWh depending on the interconnection capacity scenario) but also by taking advantage of nuclear plant available energy (thereby avoiding nuclear ramping), the latter ensuring a low carbon and low cost electricity provision. However, a special attention needs to be dedicated to the utilisation rate of the electrolyser, to keep the hydrogen production costs low enough.Last but not least, we focused on how to link the hydrogen production sites and its final use for mobility applications, the delivery infrastructure being a major issue hampering the hydrogen investments. Five transport and delivery pathways were geographically designed and economically assessed, for the French case. According to our findings, during the very first market penetration phases (1% scenario), it is more interesting to start with decentralised production that proved to be less expensive for the whole pathway at this stage.

The thesis deals with the issue of the formulation of new requirements to the development of new product with regard to the development of carbon-free economy and product safety improvement. The first part of the thesis describes the state of art of science and technique in the field of process management and the life cycle of a machine tool with emphasis placed on the machine tool development. The second part of the thesis includes a research of legislative requirements concerning machine safety and environmental aspects of the design of the machine to be manufactured. The practical part focuses on an analysis of key processes of the company with emphasis placed on safety and environmental friendly design processes with suggestions concerning improvement of processes with implemented sub-processes necessary for the identification and verification of safety. The thesis describes method implementation of ecodesign processes, which are presented on processes of company and demonstrated on product of drill. The thesis has practical implications for the introduction of automated sub-process of the identification and verification of safety requirements and integration of product development process in realization of ecodesign to company’s products.

The aim of this diploma thesis is to point out European Union´s goals such as low carbon economy, mainly future increasing the use of renewable sources as a potential source of energy. Slovak republic has due to its position in central Europe, rich in natural healing sources of water, which are considered as the most perspective sources of renewable energy in this country. The problem was solved as energy, economic and environmental analysis of Balneotherapy at Slovak Heath Spa Piešťany a.s. This analyzation was provided by real experimental measurement of temperature and flow rate and computational simulation of technological devices in opened natural healing water system. Experimentally measured data were afterwards use for elaboration conceptual design of new technological devices in order to increase efficiency of collection energy from potential renewable source of energy. The research shows that with help of new design technological devices connected to existing ones will be possible to cool down temperature of hot natural healing water from 67 °C to 21 °C, which decrease operation costs of Balneotherapy for more than 1 414 € per day. By Slovak republic entering to European Union it was necessary to accept global goals of low carbon economy. This diploma thesis provides an attention on potential energy in natural healing sources of water as renewable source of energy and helps Slovak Health Spa Piešťany to decrease amount of green-house gases released to atmosphere by efficient increasing the use of energy potential in natural healing source of water.

The subject of this master’s thesis was to find the causes of impact toughness scattering of forgings of the test disk with dimension range of 540 – 170 mm. The experimental samples were developed from steel A694 F60. To reach the main aim light microscopy, electron microscopy, EBSD technique, fractographic analysis and hardness measurement HV10 were utilized.

This thesis deals with study of surface layers of low-carbon steels formed by chemical-heat treatment. The first three chapters consist of theoretical part of the thesis, there are explained basic physical principles of these technologies and described individual types, the third chapter deals with the application of chemical-heat treated low-carbon steels in mechanical engineering. The experimental part of thesis deals with analysis of surface layers of two low-carbon steels formed using plasma nitrocarburizing and gas nitrocarburizing. The properties of these layers are evaluated based on the results of mechanical tests (hardness tests) and observation of microstructure. The thesis is completed by discussion, where the achieved results are evaluated.

The thesis deals with the issue of the formulation of new requirements to the development of new product with regard to the development of carbon-free economy and product safety improvement. The first part of the thesis describes the state of art of science and technique in the field of process management and the life cycle of a machine tool with emphasis placed on the machine tool development together with requirements and recommendations of ISO 9001:2016 – Quality Management Systems – Requirements. The second part of the thesis includes a research of legislative requirements concerning machine safety and environmental aspects of the design of the machine to be manufactured. The practical part focuses on an analysis of key processes of the company of TOS KUŘIM – OS, a.s. with emphasis placed on safety and environmental friendly design processes with suggestions concerning improvement of processes with implemented sub-processes necessary for the identification and verification of safety. A sub-process that allows for the manufacture of machines able to meet requirements of environmental friendly design is implemented to the processes. The thesis has practical implications for the introduction of automated sub-process of the identification and verification of safety requirements and implementation of the product development in the framework of future environmental friendly design development requirements to the products of TOS KUŘIM – OS, a.s.

Energy security is an important and current issue that resonates especially in resource-poor countries. In these countries, it is crucial to ensure a stable energy supply in order to maintain economic stability and ensure future economic growth. Germany is a state with low energy reserves (apart from coal reserves), and therefore this work focuses on German energy security in gas sector. The aim of this master thesis is to evaluate the current level of energy security in Germany in natural gas sector and to point out future potential threats arising from the realization of Nord Stream gas pipeline. In order to meet this goal, a new analytical framework is created, which evaluates gas security in terms of both short-term and long-term energy security indicators. This framework is based on several studies, primarily on the Model of Short-term Energy Security published by International Energy Agency. The framework is further extended by other studies dealing with the long-term dimension of energy security. Second part of the thesis deals with the role of natural gas in German energy transition (so- called Energiewende). Text examines the importance of natural gas in the situation of gradual disconnection of nuclear and coal capacities and in the ongoing decarbonization of the German economy. It was found that...

With over half of the world’s population living in urban settlements and an ongoing urbanization, cities today offer a unique opportunity to tackle climate change. Emissions of greenhouse gases derive from all products and services used, and in Sweden the average inhabitant emit 7 tons of greenhouse gases in carbon dioxide equivalents every year from privately acquired products and services, calculated from a consumption perspective. Long-term climate goals, and international climate agreements sets a limit of 1-2 tons. Lifestyle changes are important to achieve sustainable development, but planning practices today generally do not try to influence citizens’ consumption, and is presumed cannot affect inhabitants’ consumption of food, clothes, electronics, furniture, etc.  This thesis investigates how planning and the built environment can practically encourage more sustainable consumption patterns, and which of these practices would be suitable to implement in the current sustainability project of Norra Kymlinge. The study concludes that sustainable consumption patterns could be encouraged in Norra Kymlinge through: collaborative living, sharing infrastructure, green leases, food production, personal measurement, and semi self-built apartments. For future research, more quantitative studies on the topic are suggested.

The transportation sector plays a significant role in global carbon emissions, emphasizing the need for transitioning to alternative fuel technologies. This thesis primarily aims to examine the factors that influence small road freight transport companies in Sweden when transitioning to alternative fuel technology. The focus is on identifying these determinants and their respective significance, utilizing a company internal Resource-Based view as the analytical framework. Semi-structured interviews were conducted among small road freight transport companies, with data analyzed using pattern and keyword matching analysis. The results reveal multiple determinants within financial, technological and organizational resources. Range, purchase cost, and customer demand emerged as the most influential determinants, with range limitations hindering adoption and high costs deterring investment. However, customer demand for eco-friendly transport presents an opportunity for companies to gain a competitive advantage. Company size, cargo type, and operational constraints also influence decision-making. In the data selection, micro companies exhibit a higher propensity for drop-in alternative fuels, while small-sized companies engaged in short-haul transportation are more open to alternative fuel adoption and riskier investments. Risk-averse followers tend to stick to established practices. Policymakers are recommended to invest in infrastructure, provide subsidies, and implement regulations to incentivize adoption, while vehicle producers should optimize designs and collaborate with fuel producers. Further research is advised to investigate the viability of different low-carbon fuel alternatives, explore challenges and motivations faced by different company types, and conduct comparative studies. Quantitative research methods can offer broader insights into this area of study.

Объектом исследования являются причины зарождения протяженных вязких разрушений магистральных трубопроводов. Материалом исследования являлась низкоуглеродистая трубная сталь 06Г2МБ. В работе рассмотрены возможности, по средствам программного обеспечения Thermo-Calc, установить оптимальные параметры производства стали 06Г2МБ для недопущения формирования в металле возможных первопричин зарождения вязких трещин. Проведены термодинамические расчеты по определению температуры АC3. Построены математические модели, позволяющие оптимизировать химический состав стали в момент выплавки с целью предотвращения химической неоднородности в центральной области непрерывно-литых слябов (фазовой ликвации) и, соответственно, минимизировать количество дефектов кристаллизации. / The research object is the causes of the extended viscous fractures origin of main pipelines. The study material was low-carbon pipe steel 06Mn2MoB. The paper considers the possibilities, using the Thermo-Calc software, to establish the optimal parameters for the steel 06Mn2MoB production to prevent the formation of possible root causes of the viscous cracks initiation in the metal. Thermodynamic calculations were carried out to determine the AC3 temperature. Mathematical models have been constructed that allow optimizing the chemical composition of steel at the time of smelting in order to prevent chemical heterogeneity in the central region of continuously cast slabs (phase segregation) and, accordingly, to minimize the number of crystallization defects.