Microstructure and electrical conductivity of YSZ thin films prepared by pulsed laser deposition

Yttria-stabilized zirconia (YSZ) is the most common solid electrolyte material used e.g. in ceramic fuel cells. Thin films of YSZ were deposited on c-cut sapphire single crystals by pulsed laser deposition using a KrF excimer laser focused on a polycrystalline 8 mol% Y2O3-stabilized ZrO2 target. Depending on the substrate temperature and the oxygen background pressure during deposition, different microstructures are obtained. XRD and high-resolution SEM revealed the formation of dense amorphous films at room temperature. At 600°C preferentially (111) oriented polycrystalline films consisting of densely agglomerated nm-sized grains of the cubic phase resulted. Grain size and surface roughness could be controlled by varying the oxygen background pressure. RBS and PIXE evidenced congruent transfer only for a low number of pulses, indicating a dynamical change of the target stoichiometry during laser irradiation. The in-plane ionic conductivity of the as-deposited crystalline films was comparable to bulk YSZ. The conductivity of initially amorphous YSZ passes a maximum during the crystallization process. However, the relative changes remain small, i.e. no significant enhancement of ionic conductivity related to the formation of a nanocrystalline microstructure is foun

Phonons from neutron powder diffraction

The spherically averaged structure function \soq obtained from pulsed neutron powder diffraction contains both elastic and inelastic scattering via an integral over energy. The Fourier transformation of \soq to real space, as is done in the pair density function (PDF) analysis, regularizes the data, i.e. it accentuates the diffuse scattering. We present a technique which enables the extraction of off-center phonon information from powder diffraction experiments by comparing the experimental PDF with theoretical calculations based on standard interatomic potentials and the crystal symmetry. This procedure (dynamics from powder diffraction(DPD)) has been successfully implemented for two systems, a simple metal, fcc Ni, and an ionic crystal, CaF$_{2}$. Although computationally intensive, this data analysis allows for a phonon based modeling of the PDF, and additionally provides off-center phonon information from powder neutron diffraction

Inclusion of logistical regulations in land allocation agreements Investigation of a public landowner in a city development project

The thesis aims to investigate how Älvstranden as a public landowner can affect developers and contractors to adhere logistical solutions by the means of land allocation agreements. Research questions encompass which areas of responsibility Älvstranden has as a public landowner, how land allocation agreements can be utilized for conveying logistical regulations and how stakeholders perceive these regulations. The investigation has been conducted in an abductive manner and has constituted of a literature study, including topics of construction logistics, land allocation agreements and public private partnerships. Furthermore, 13 interviews have been conducted with stakeholders involved within project Masthuggskajen, Uppsala Bygglogistikcenter, a third-party logistics provider, logistics consultants and a logistics researcher. The study shows that common and efficient solutions to address the implications of construction transports are construction logistics centres (CLC). Furthermore, land allocation agreements and organisational relationships within public-private partnerships influence projects proceedings to a great extent. For this reason, land allocation agreements must be balanced in terms of alignment of incentives, allocation of support, costs and benefits, and conveyed solutions must contain attributes of feasibility. If not, there is a risk of distrust and a favour of opportunistic behaviour, thus jeopardizing project success. Stakeholders in the form of developers, contractors and third-part logistics service providers have diverse opinionsregarding whether the logistical element should be included within land allocation agreements or not, to which extent, and how it should be formulated. However, the majority express no aversion of inclusion if it brings economic incentives. This master thesis provides contributions for Älvstranden by suggesting that they should implement logistics in land allocation agreements through stipulating regulations in a comprehensive manner. This should be done by internally employ logistic competence. Finally, the positive results from Uppsala Bygglogistikcenter indicate that the utilization of a CLC would be a great option within vision Älvstaden