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By harnessing the powers of polycrystalline materials an unprecedented, technologically-driven age has taken formover the last 100 years. The polycrystal is today, arguably, the most central building block for electronics, renewableenergy, transportation and medical equipment industries. This material class is the reason for the emergence of thepowerful microprocessors, semiconductors, memory chip
Fuel cells are promising for future energy systems, since they are energy efficient and, when hydrogen is used as fuel, there are no emissions of greenhouse gases. Fuel cells have during recent years various improvements, however the technology is still in the early phases of development. This can be noted by the lack of a dominant design both for singe fuel cells, stacks and for entire fuel cell
Proton exchange membrane (PEM) fuel cells are known as environmental friendly energy conservation devices, and have the potential to be suitable alternative power sources. The cost and durability of a PEM fuel cell are strongly affected by the involved transport phenomena and reactions, which are two major challenges to be overcome before commercialization. Modeling and simulation are crucial for
The studies presented in this thesis concern hydronic space heating systems connected via heat exchangers to a district heating network: referred to as an indirect connection. The objective has been to improve the reliability of district heat supplies and to lower the return temperature from consumer substations. Two of the disadvantages of an indirect connection have been addressed: the thermodyn
The feasibility of the global energy transition may rest on the ability of nations to harness hydrogen's potential for cross-sectoral decarbonization. In countries historically reliant on natural gas for domestic heating and cooking such as the UK, hydrogen may prove critical to meeting net-zero targets and strengthening energy security. In response, the UK government is targeting industrial decar
Aqueous lithium-ion batteries (ALIBs) are promising for large-scale energy storage systems because of the cost-effective, intrinsically safe, and environmentally friendly properties of aqueous electrolytes. Practical application is however impeded by interfacial side-reactions and the narrow electrochemical stability window (ESW) of aqueous electrolytes. Even though higher electrolyte salt concent
Hydraulic balancing of heat distribution systems in buildings plays an important role in improving indoor thermal conditions as well as reducing energy consumption for space heating. Building energy models typically do not incorporate thermal comfort while it is essential for hydraulic balancing to do so. This paper proposes a methodology that assesses the impact of hydraulic balancing on the ener
Wood based energy is the main source of cooking and heating fuel in Sub-Saharan Africa. Its use rises as the population increases. Inefficient cook stoves result in fuel wastage and health issues associated with smoke in the kitchen. As users are poor women, they tend not to be consulted on cook stove development, hence the need for participatory development of efficient woodfuel cooking systems.
Polyphenolic compounds in bark are resources of great interest to produce renewable chemicals and several different technologies are available or under early development for the extraction of these types of compounds. Since critical environmental effects of a product are often set during the design phase, it is important to use life cycle assessment (LCA) to identify the steps resulting in the lar
The concluding chapter first summarizes some of the volume’s main results along the four evaluative themes. In terms of coherence and management, the three policy fields under scrutiny – renewable energy, fossil fuel subsidy reform and carbon pricing – are roughly marked by coordination, rather than competition or outright harmony. Regarding legitimacy, the specializations and work backgrounds of
Housing expenses have the highest share in household budgets of low-income groups in Copenhagen leading to affordability problems. To provide affordable housing (AH) for low-income groups, the municipality developed a zoning plan in 2015 aimed to reserve up to 25% of land for new AH production. This qualitative case study compares the affordability of homes produced by private sector and nonprofit
In many organizations, the Chief Information Officer is considered to preside over a separate function, providing a service to the business. Discussions about governance are confined to properties of this service, e.g. through a service level agreement. Members of the CIO’s staff are often seen as technical experts possessing esoteric skills desired but not understood by other staff. Many research
This article contains an overview of the current proposals of converging IP-networks with PSTN. We describe Parlay and Open Service Access( OSA), two of the most promising architecture.
