Chalmers Open Digital Repository
Välkommen till Chalmers öppna digitala arkiv!
Här hittar du:
- Studentarbeten utgivna på lärosätet, såväl kandidatarbeten som examensarbeten på grund- och masternivå
- Digitala specialsamlingar, som t ex Chalmers modellkammare
- Utvalda projektrapporter
Forskningspublikationer, rapporter och avhandlingar hittar du i research.chalmers.se
Enheter i Chalmers ODR
Välj en enhet för att se alla samlingar.
Senast publicerade
- Metal intercalation studies in epitaxial graphene on SiC(2026) Chelakkoden, UmmusalmaEpitaxial graphene on silicon carbide (epigraphene) enables the synthesis of atomically thin heteroepitaxial crystals via the intercalation of metallic atoms at the interface between graphene and the SiC substrate. Metal intercalation involves introducing metal atoms at high temperature beneath the so-called carbon buffer layer, leading to its decoupling from the substrate. As a result, the buffer layer and the graphene atop transform into quasi-freestanding bilayer graphene. This work explores the intercalation of epigraphene with three metals: gold, indium, and bismuth, and reports the characterization results using surface science methods, Raman spectroscopy, and electron transport measurements. The lowest intercalation temperatures observed for the tested metals are T = 300 °C for indium, T = 400 °C for bismuth, and T = 840 °C for gold. The surface roughness was studied for all metals using atomic force microscopy, and the integrity of graphene was verified using Raman spectroscopy. Electron transport measurements on the heteroepitaxial films down to T = 2 K revealed that intercalation of epitaxial graphene enhances spin–orbit coupling (SOC), as evidenced by the observation of weak antilocalization corrections. Remarkably, the intercalated metals, being covered by graphene, are air-stable and allow for the fabrication of Hall bar devices using electron beam lithography. These results establish a foundation for studying enhanced SOC in engineered graphene heterostructures, with potential applications in emerging electronic devices.
- Modeling and Parameter Estimation of Planing and Semi-Planing Marine Vessels under Colored Disturbances(2026) Ulstein, Oskar; Öhman, EdvinA linear grey-box Multiple Input Multiple Output (MIMO) model describing ship attitude motion is derived from established nonlinear equations for ship motion. The model describes how five control surfaces: two fins, two interceptors and a rudder control the roll, pitch and yaw dynamics of a vessel. The model is developed for ship stabilization control design and consists of 15 parameters, neglecting the translational states surge, sway and heave. These neglected states are concluded to introduce errors in the model through residual correlation analysis, but the model is considered adequate for control design through empirical frequency domain validation using SPAFDR. To ensure the model is applicable to the different operating states of a planing vessel (displacement, hump and planing), it is validated at the operating states respective speed of a test vessel: 10, 15 and 20 kt. Input-output data is collected in open-loop system identification experiments. To make this possible, an excitation signal for MIMO system identification is proposed as a modified PRBS7 signal. The excitation signal is applied periodically to separate the ship’s deterministic output from the noise. The noise is analyzed, modeled as an ARMA process and concluded to be time-variant. Parameter estimation of the proposed ship model is performed using a batch Prediction Error Method (PEM) in the presence of colored noise. Furthermore, two recursive parameter estimation algorithms are implemented and tested on data with colored noise (specifically a Recursive Output Error Model and a Recursive Instrumental Variable State Varying Filter) to allow for parameter estimation on limited hardware, lacking the ability to use batch estimation methods.
- Mötesplatser i Gamlestaden(2026) Wall, Clara
- KUL LAGRET(2026) Nguyen, Elisa