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Senast inlagda
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.
Concept exploration; Integrating atmospheric water generation systems onto spray drying process
(2025) Thorngren Sollenberg, Mikael
Water is a scarce resource in many places of the world, and the problem with access to clean water increases. There are several ways to mitigate the problem and produce clean water and one of them is atmospheric water generation (AWG). Although water is a scarce resource it occurs as a residual product from the drying process spray drying. The Uppsala based startup company Drupps has developed technology for water recovery using a liquid desiccant to absorb the residual hot fumes emitted into the atmosphere. The company has built a pilot plant in a test facility with the necessary components for the system.
The purpose of the thesis was to develop a product architecture to be retrofitted on existing productions that use spray dryers. The target customers was productions with spray dryers emitting approximately 250 000 cubic meters of moisture per hour. To develop a customer focused product, the product development method is based on the one presented in the book “Product design and development” by Karl T. Ulrich and Steven D. Eppinger from 2016. The thesis elicits customer needs, mainly through interviews, searching for solutions that solve similar problems, decision matrices.
The final concept design is an modular architecture, consisting of a load-carrying structure of a square cube frame with interface to enable more cubes to be connected. The majority of the components of the Drupps atmospheric water generation system fit inside the cubic frames, and by increasing and alternating the three different cubes, the system can fit a wide variety of volumetric flows as well as different potential customer segments.
Electrified semitrailer longitudinal wheel-torque control within safe operation and how the communication between vehicle units affects the motion performance
(2024) Hermansson, Harald; Tjärnlund Leppämäki, Joakim
In the electrification of the heavy duty fleet, electrified semitrailers are a big talking
point and a lot of work is being put into researching how they could work and how
they should be controlled.
This thesis focuses on how two different levels of communication will affect the
performance, stability and drive-ability of an electric semitrailer. The first level of
communication follows the ISO 11992-2:2014 standard, which mainly allows for only
brake-torque requests from the tractor to the trailer (called type 3 communication
in this thesis). This will be compared to a new communication interface that allows
more request signals from the tractor to the semitrailer and more data in both
directions (called type 4 communication). This means all wheel speeds, axle loads
and torque requests can be communicated back and forth at all times.
Four different controller algorithms were created. One for the type 4 level communication,
and three for the type 3 level, where two are equipped with two extra sensors,
a coupling force sensor and an articulation angle sensor. The last one only relies on
the sensors available in a standard semitrailer according to ISO 11992-2:2014.
The controllers were tested in a high-fidelity simulation environment in four different
use cases, where their motion performance was measured and compared to a tractor
with a non-driven semitrailer. All vehicle combinations performed better than the
normal tractor and semitrailer combination, although they were more prone to failures
such as jackknifes and rollovers due to the added powertrain on the electrified
semitrailers.
In conclusion, having an electrified semitrailer can improve the performance of the
vehicle, but the level of communication did not have a big impact on the results
from the simulated use cases investigated in this thesis.
Impact of Environmental Factors on Breakdown Characteristics of Air Insulation in Power Distribution Components of Electrical Aircraft
(2025) Koseoglu, Ali
Abstract
Growing concerns on environmental issues challenge scientists and engineers to create greener technologies on a vast area of industrial and commercial applications. Aviation, as one of the major human activities responsible for the environmental impacts, is among the most trending topics in this effort for transition to more eco-friendly technologies.
While electrical aircraft have been experimented from as early as 1885, achieved by Gaston Tissandier by flying a small airship powered by an electric motor, the scale of aircraft needed today is significantly larger. The more powerful electrical powertrains needed to achieve this goal call for higher levels of system voltage to reduce the weight and enable competitive designs.
Although well-studied for land and sea applications, the use of high voltage systems is a relatively new area for aviation systems. A growing demand for research and development is emerging for creating regulations, technical standards, testing methods and know-how for applying high voltage solutions in electrical aircraft.
This thesis explored the implications of implementing high voltage direct current systems to be used in hybrid or all-electric electrical aircraft with a focus on the performance of the dielectric systems under expected ambient conditions in high altitudes, namely extreme ambient temperatures (TA), low air pressure (p) and various relative humidity (RH) levels.
To achieve the goal, experimental setups of vacuum and climate conditioning chambers were utilized to create ambient conditions an electrical aircraft may experience, and respective breakdown voltage for the insulation system for various scenarios were measured.
It was observed that lower air pressure and relative humidity levels create unfavorable conditions for the insulation system, while lower ambient temperature increases the breakdown voltage. The combined effect of higher altitude conditions was evaluated to be of performance depreciative nature for the insulation systems as the altitude increases up to 25,000 feet. It was also concluded that significantly lower insulation performance may emerge around the dew point of water in the air.