Chalmers Open Digital Repository

Welcome to Chalmers Open Digital Repository!

Here you can find:

Student theses and papers
Digital special collections, such as Chalmers modellkammare
Selected project reports

Research publications, reports and dissertations can be found in research.chalmers.se

Communities in Chalmers ODR

Select a community to browse its collections.

Now showing 1 - 2 of 2

Recent Submissions

Developing N-alkylated fatty amines based on glycerol-derivable building blocks.
(2026) Zarowiecki, Martina
Nouryon is a leading company in specialty chemicals and a pioneer in surface active molecules. One of its key product classes is nonionic surfactants, widely used in agriculture, personal care, oilfield and more. Currently, Nouryon produces alkoxy lated nonionic surfactants, where the hydrophilic headgroup is based on epoxides sourced from fossil raw materials. Alkoxylated amines are paticulary important in agriculture, where they serve as effective adjuvants in glyphosate based herbicides. Due to environmental concerns and the interest in fully bio-based alternatives to alkoxylated surfactants, alternative synthetic routes and starting materials for the hydrophilic headgroup is being investigated in this study. One readily available bio based material which could act as a good alternative to epoxides is glycerol. In this study, alternative synthetic routes based on glycerol derivable building blocks are being investigated with the intention of producing fully bio-based nonionic sufac tants, focusing on the N-alkylation of fatty amines. The synthesis is conducted in labscale and evaluated with NMR and GC-MS/FID. The results showed that reacting glycerol carbonate and fatty amines with cata lyst such as Ca(OH)2, MgO or ZnO, at temperatures above 190 °C yielded sig nificant amount of alkylated products such as N-alkyl serinol carbamates, 2,3 dihydroxypropyl amines and bis-2,3-dihydroxypropyl amines. While total amount of alkylation was similar across catalyst, Ca(OH)2 resulted in higher yields of both 2,3-dihydroxypropyl amines and bis-2,3-dihydroxypropyl amines. Under one set of optimized conditions (2 eq. glycerol carbonate, 0.3 eq. Ca(OH)2 and 1 eq. of fatty amine, 220 °C, 6h.), 86 % yield of alkylated product was reached. Additionally, doing a onepot synthesis starting with readily available materials such as urea and glycerol instead of glycerol carbonate, resulted in less selectivity towards alkylated products. For both approaches, the reaction showed to be heavily shifted towards N alkyl serinol carbamates, which limits formation of bis-2,3-dihydroxypropyl amines. The yield of 2,3-dihydroxypropyl amines could be increased by base hydrolysis of N-alkyl serinol carbamates. Based on these findings, by applying the optimized conditions, it is possible to attach a hydrophilic headgroup with a hydrophobic tail from sources that could be derived from renewable materials with this chemistry. The hydrophilic headgroup could be based on polyglycerol carbonates derived from recycled and bio-based CO2 or urea and polyglycerol. The hydrophobic tail could be based on fatty amines derived from either tallow or coconut.
Coordinated approach for port operation and vessel traffic scheduling in Roll-on Roll-off (Ro-Ro) terminals: a case from Sweden
(2026) Gupta, Avinash
Shipping is the foundation of international business, includes various stakeholders such as terminal, shipping lines, cargo owners, and port authority. These stakeholders are important for the efficient supply chain and logistics operation. One of the stakeholders that is terminal act as a connecting entity among all other stakeholders. Therefore, the terminal operation efficiency depends on the coordination between terminal, shipping line and cargo owner. The thesis explores on finding the challenges causing disruption in the Ro-Ro terminal operation and the current digital technologies used to reduce these challenges. The methodology comprises of a deductive research approach, that has been applied to develop the Theoretical Framework. The study emphasized to collect data through qualitative research method from a single case study that includes semi-structured interviews. The data collection from interviews were conducted with two terminal managers and one ship’s cargo officer. The themes from literature review were highlighted as challenges in cargo operation, vessel scheduling and adoption of DT technology in the thesis. The findings of the thesis showed that the digital technologies were present in the terminal operation, but the full utilization could not be achieved. The thesis provided the useful insights on using DT simulation model and requires coordination between different stakeholders to enhance port operational efficiency.
A better understanding of loss prevention in the maritime industry – a case study in best practices
(2026) Swenzen, Eric
Maritime accidents cause significant human, economic and environmental losses, and there is a large societal need to minimize the accidents and claims. 2,646 accidents were reported on average annually between 2014 and 2022. Loss prevention is characterised by the analysis of past claims, inspections and general advice for Protection & Indemnity (P&I) Club members. The project was conducted by collecting qualitative data from key onshore management personnel at shipping companies, with no or few claims. These companies were selected by the insurance company The Swedish Club. The results and the analysis are presented in this thesis. The research is limited to data collected from six companies. The information was gathered from relevant sources of academic literature and partly from semi-structured interviews. Loss prevention practices are limited to the participating companies. Data collected shows that the human factor is causing most of the maritime accidents, directly or indirectly. The primary research shows that a successful corporate culture, which involves the crew in all aspects of designing, equipping, training and auditing, helps to keep accidents at a minimum. This includes a friendly, open and non-blame corporate culture, where all suggestions and opinions are considered.
Development of a HBr-Based ICP-RIE Process for Smooth and Anisotropic Etching of III–V Semiconductors
(2026) Nyström, Emil
This thesis presents the development of a dry etching recipe using hydrogen bromide (HBr) for the fabrication of InP/InGaAs-based heterostructures. The recipe aims to replace a methane-based process to avoid chamber contamination while maintaining a highly directional etch profiles and smooth surfaces. HBr in particular was selected as an alternative etching chemistry due to its potential to achieve desired result, while also offering reduced plasma-induced damage compared to conventional processes. Though systematic research and optimization of process parameters such as, pressure, temperature, ICPpower, RF-power, and flowrate, a recipe was developed that produces sidewall-angles up to 88.9 degrees and smooth surfaces. A hard mask material combination of Ni and Cr was found to be optimal which yields a selectivity up to 22:1, and a Si carrier should be used to add a passivation mechanism to the etching recipe. The developed recipe has successfully been applied to Fermi-level managed barrier diodes (FMBD), resonant-tunnelling diodes (RTD), and heterostructure barrier varactors (HBV), demonstrating consistent etch-performance across different InP/InGaAs-layer stacks. Electrical measurements confirmed functionality of devices fabricated using the new process, validating the suitability as a replacement for the methane-based dry etch process recipe.
Investigation into the efficiency of a PLM system
(2025) Kåreby, Markus
This thesis explores time-related data recorded within a Product lifecyle management (PLM) system, with a focus on Engineering Change Requests (ECRs). A total of 166 ECRs were collected, categorized into four distinct cases, and analyzed to understand process times, task distribution, outlier occurrences, and iterative work. Data was manually gathered and visualized using box plots. The analysis showed that cases handling Product Change Requests (PCRs) had significantly longer and more variable processing times, often due to inactive time being recorded as active work in the data. Furthermore, a noticeable proportion of outliers and iterative work were found in certain data sets generally belived to be caused by the requirement of PCRs. Limitations in the data included lack of clear project identifiers, inconsistencies in how time was recorded, and the inability to differentiate between rework and multi-article tasks. Despite these constraints, inefficiencies were identified such as idle time, undocumented steps, and inconsistent timestamping. The thesis finds that the PLM data is not fully representative of actual work, but inefficacies are and were still possible to be identified from the data. Recommendations for improving data quality include automation of data collection, better categorization of ECRs, and improving data tracking. These measures would support better process understanding and lead to potential efficiency increase in the product change workflows