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Senast inlagda
Life Cycle Assessment of Organic Waste Treatment by Composting and Anaerobic Digestion for the City of Cuenca – Ecuador
(2025) Cobo, Juan Carlos; Tallada Cebrián, Adria
This thesis explores the environmental performance of anaerobic digestion (AD) and composting as waste management solutions for the organic fraction of municipal solid waste (OFMSW) in Cuenca, Ecuador. Using Life Cycle Assessment (LCA) methodologies, it evaluates key environmental impacts such as global warming potential and photochemical oxidant formation, aiming to identify the most suitable method for reducing the amount of organic waste sent to landfills.
The results indicate that anaerobic digestion has strong potential to reduce greenhouse gas emissions, particularly when biogas is effectively captured and used. On the other hand, composting, while less effective in terms of emission reductions, is more cost-efficient and can play a valuable role in improving soil health. Despite these benefits, both technologies face considerable challenges in the Latin American and Caribbean (LAC) region, where the focus is often still on meeting basic waste management needs, such as establishing sanitary landfills. The high costs and limited development of AD in the region also raise concerns about its viability.
The study highlights the importance of understanding the composition of OFMSW, as this has a direct impact on the efficiency of AD systems. Future research should explore the potential of co-digesting OFMSW with other types of organic waste to boost biogas production. Additionally, factoring in socio-economic aspects—such as the costs of implementation, potential economic gains from energy generation, and effects on local communities—will provide a fuller picture of the sustainability and practicality of these technologies.
Ultimately, the findings suggest that while both AD and composting offer clear environmental benefits, their adoption must be guided by local priorities and infrastructure readiness. Addressing these regional factors is crucial for optimizing resource recovery and minimizing environmental impacts.
Measurements of heat current and its fluctuations in superconducting quantum systems
(2025) Nordqvist, Ludvig
As the quantum systems we can control and manipulate increase in size, understanding
heat dynamics becomes increasingly important. In this master’s project,
we study the heat currents flowing between two out-of-equilibrium reservoirs across
a superconducting quantum circuit composed of two mutually coupled, flux-tunable
qubits. Electrical noise applied to the flux line of a qubit induces incoherent coupling
between the modes in the single excitation manifold. Each mode is coupled
to a thermal bath, realized with microwave waveguides. By coherently driving one
of the modes to its first excited state, a heat current is induced. We measure heat
currents on the scale of a few attoWatts, along with the fluctuations in said current.
The results are compared to simulations that use full counting statistics to
compute the currents and fluctuations of the process. These findings pave the way
for demonstrating advantages of quantum systems over classical ones in quantum
thermodynamics.
Agent-centric temporal logic planning for autonomous vehicles
(2024) Aline Eikeland
To responsibly introduce autonomous vehicles in practical use, we first need ensure their safety. However, testing autonomous vehicles require more time than what is actually feasible. Instead we can create a controller using synthesis, which provides a safe implementation for a formal description of the environment and system demands. Its practical use is limited due to how it is strongly affected by state space blowup, a factor heavily restricting the size of model variables.
We design an agent-centric model for a vehicle with the objective to avoid obstacles and navigate towards a target, believing that this novel perspective will limit the state space issues while it, unlike other models with similar purpose, does not require live synthesis or preplanning on a scaling number of specifications. Further, we showcase a possible framework for integrating the controller into a physical vehicle system. We also present a simulator, allowing one to freely explore the behaviour of the agent-centric model.
The final result is a model that is fully synthesised to a single controller in preplanning. The navigational model shows promise in its adaptability to unexpected map changes but fails to navigate through every task, getting stuck in certain situations and acting against common traffic norms in certain situations.
We believe that the agent-centric model could potentially be used in a more flexible vehicle controller, and that both the agent-centric spatial approach and the directional target navigation are possible perspectives worth considering for work in this area.
Synthesis and characterisation of nanometric simulated nuclear fuel (SIMfuel)
(2024) Bergström, Julia
In this project a procedure for the synthesis of Ce(III) and La(III) doped UO2 SIMfuel was tested. The methods include electrochemical reduction of aqueous U(VI),
Ln-doping, co-precipitation of nanometric doped UO2 powder, and pressing and sin tering of pellets. The aim was to synthesise SIMfuel with a high degree of dopant
homogeneity and a nanometric grain structure found in irradiated uranium fuel with high burn-up structure. Four nanometric pellets were made, two with no dopants,
one with 1% La, 1% Ce and one with 1% La, 5% Ce. Reference pellets were also made through U(VI) reduction in high temperature H2 atmosphere. Elemental com position, unit cell dimensions, density, porosity, grain size and dopant homogeneity were characterised for nanometric pellets and reference pellets. Both types of pellets were found to have good homogeneity of dopants at both doping levels. The grain size for the nanometric pellets were found to not actually be nanometric, with a size range of around 1-25 µm. It is assumed that the high temperature sintering caused significant grain growth for the nanometric pellets.
Revolutionerande golfträningshjälpmedel
(2024) Larsson, Oscar; Bachalan, Jacob
This thesis project introduces the development of 3D-printed training plates for golf putting, aiming to mimic the feel and friction of a real putting green. Through experimental evaluations, various materials and surface configurations were tested to achieve targeted friction characteristics, with TPU 95A, PETG, PLA and ABS emerging as a prominent candidate. Controlled design experiments were conducted to determine parameters ensuring optimal friction and stability. The results reveal that the developed prototype provides a reliable training surface with enhanced realism over existing options. This study underscores the potential of 3D printing in creating innovative training aids for sportsapplications.