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Senast inlagda
Reference values for sustainability assessment - Incorporating monetary terms for enhanced decision-support
(2025) Loman, Rebecca
Large-scale infrastructure projects involve substantial investment and have far-reaching
environmental consequences. As regulatory standards grow increasingly stringent, for ex ample in the wastewater sector where treatment requirements are continuously updated,
developers are often required to upgrade or construct new facilities to satisfy regulatory
demands. Decision-making in such settings must account for multiple, sometimes conflict ing, criteria, and multi-criteria analysis (MCA) offers a structured means of comparing
alternatives across selected criteria. However, the weighting step within MCA remains
susceptible to subjectivity and a lack of transparency and objectivity. This study inves tigated whether integrating reference values, derived from governmental guidelines and
accepted industry norms, could support more objective and consistent weighting. The
analysis focused on the environmental sustainability criteria: climate impact, energy use
as a resource, and nutrient discharge (nitrogen, phosphorus, and organic matter) to re ceiving waters. It further examined the potential of basing weights on decision-makers’
willingness to pay (WTP) for improvements in specific criteria. The conventional MCA
weighting-methodology was refined for WTP input and cost weighting. Workshops were
conducted to compare conventional percentage weighting with WTP-based weighting,
and participants reported greater confidence when relying on reference values rather than
subjective estimations. When comparing previous assessments, conventional weighting
exhibited wide variations both within and between groups. Weighted score ratios calcu lated from conventional weightings were compared to collected reference values, revealing
noticeable inconsistencies. These findings indicate that conventional methods risk in consistency and bias, while WTP anchored in reference data contributes to improved
transparency and reliability. Incorporating such reference values into MCA thus offers
valuable decision-support, enabling more robust, evidence-based choices in the planning
of high-cost, environmentally significant infrastructure projects.
Sustainability assessment using multicriteria analysis for wastewater handling
(2025) Huang, Shiyun
This study presents a sustainability assessment of three wastewater treatment technologies—
Activated Sludge (AS), Membrane Bioreactor (MBR), and Aerobic Granular Sludge (AGS)—
using the case of the Västra Stranden Wastewater Treatment Plant (WWTP) in Halmstad, Sweden.
A Multi-Criteria Decision Analysis (MCDA) approach was applied to evaluate and compare the
technologies across environmental, economic, technical, and social dimensions. Two different
weighting methods were tested: a traditional percentage-based model and a value-based model
using Weighted Score Ratios (WSR). Data collection included quantifiable performance indicators,
expert judgment from professionals at Laholmsbuktens VA (LBVA), and input from students in
an advanced wastewater engineering course.
The value-based model assigns monetary values to each sustainability criterion, helping to clarify
trade-offs and improve transparency in the decision-making process. Results from both workshops
showed that the value-based approach was more effective in identifying which criteria had the
greatest influence on overall sustainability.
This study highlights the strengths of combining technical data with structured stakeholder input
and suggests that value-based MCDA models can support more robust and balanced decisions in
wastewater planning.
Surface characterization and grinding of Duplex 2205 Stainless Steel slabs
(2025) Ahmad, Ari
This study investigates the optimization of grinding processes for duplex 2205 stainless steel slabs at Outokumpu Avesta works. The primary objective is to analyze and enhance these processes to achieve cost reductions, increased productivity, and improved material processing efficiency. To fulfill this aim, a combination of theoretical analysis and practical experiments has been conducted, with a particular focus on the effects of different grinding methods on oxidation levels and surface quality.
Through the evaluation of various grinding conditions, the study identifies opportunities for process improvements that can enhance production efficiency. It is shown that implementing coarse grindings process only can reduce total material loss by 21 ton, decrease grinding time by 200 hours, and result in potential savings of 40% in grinding wheel costs during the reference period. The findings highlight the need to balance cost-effectiveness, product quality, and environmental considerations. This work aims to support Outokumpu's long-term development strategy while contributing to the company's competitiveness in the global market
Aggregation Kinetics and Characteristics of Truncated α-synuclein Variants 1-119 and 72-140 Related to Parkinson’s Disease A biophysical investigation of truncated forms of the Parkinson’s protein α-synuclein using kinetic assays, atomic force microscopy, and cell viability assays
(2025) Gannholm, Andreas
Parkinson’s disease is a neurodegenerative disorder associated with the pathological aggregation of the protein α-synuclein (α-syn) into amyloid fibrils. While extensive research has focused on the structure and aggregation kinetics of full length α-syn (FL), recent findings suggest that truncated variants are common in the brain and may exhibit distinct aggregation behaviors and structural properties.
This master thesis aims to investigate the α-syn truncations 1-119 and 72-140 and compare them to the FL protein. Specifically, the study examines their aggregation kinetics, the morphologies and secondary structure of the resulting aggregates and finally their cytotoxic effects on human neuroblastoma SH-SY5Y cells.
The results show that there are distinct differences in aggregation behaviors of these truncated variants compared to FL α-syn.
The 72-140 variant aggregates rapidly but does not form fibrils, instead it produces large globular oligomers which lack β-sheet structure. These aggregates are not cytotoxic to SH-SY5Y cells, possibly due to the absence of an ordered fibrillar structure and/or their size. Although 72–140 does not appear to co-form fibrils with other variants, it was found to have some catalytic effect on their aggregation.
The 1-119 variant aggregates faster than FL α-syn. The kinetic curves are characterized by a reduced lag time and they form shorter fibrils, suggesting that enhanced nucleation may explain the faster aggregation rate. The 1-119 fibrils are toxic to cells, but less toxic than FL fibrils. When co-aggregated with FL or 72-140 the aggregation kinetics are predominantly governed by the 1-119 variant. FL and 1-119 do not appear to co-form fibrils, but rather form fibrils independently while influencing each other’s aggregation kinetics.
These results furthers the understanding of truncated α-syn variants and their possible involvement in Parkinson’s disease initiation and progression. This project also creates a base for further research in this area, especially for further investigations of 72-140 and other C-terminal fragments.