https://www.um.edu.mt/library/oar/handle/123456789/145210 2026-07-21T05:55:57Z 2026-07-21T05:55:57Z https://www.um.edu.mt/library/oar/handle/123456789/148128 2026-07-20T08:48:45Z 2026-01-01T00:00:00Z

Title: Development of an analytical framework for robot-inclusive homes, and of an autonomous assistive robot Abstract: Robotic assistance in domestic environments is gaining importance for supporting older adults and people with impairments. Many domestic robots depend on complex algorithms and high computational power, which raises cost and makes integration into ordinary homes difficult. At the same time, most homes are not arranged to help robots see, reach, or move well. This research addresses that mismatch by treating the person, the robot, and the home as one measurable system, and by showing that a simple robot can deliver useful assistance in a space designed to support it. The research develops a Robot-Inclusive Space framework that formalises design and evaluation across four linked measures. Human Impairment Index evaluation and task demand set an explicit upper bound on robot capability through the Robot Complexity Index. The Robot Inclusive Space Index quantifies how layout choices support observability, accessibility, and manipulability. The Space Convertibility Index estimates the effort to reach a target layout under practical limits of cost, effort, and time. The study follows a structured RIS workflow: impairments are evaluated and translated into remaining capacities, mapped to task demands, and used to identify the minimum robot features required. RIS home modifications are then defined to support both robot operation and human needs, and their feasibility is assessed in terms of cost, effort, and time. Using a teleoperated baseline, MARIS-I, the study motivates MARISII, a semi-autonomous platform sized for small homes that combines lightweight mapping, marker-aided localisation, goal-biased curvature-bounded planning, and suitable sensor placement with simple task stations consistent with the framework. Validation in physical layouts designed according to Robot-Inclusive Space principles uses consistent hardware and repeatable trials to assess reliability and efficiency. Clear sightlines, uncluttered paths, structured object placement, and marker cues keep mapping and planning lightweight and support pick and place within defined zones. Across experiments, RIS-guided design reduces planning latency, turn counts, and processor load while maintaining path quality, enabling MARIS-II to operate more reliably with lower computation. Overall, the results show that measurable improvements in observability, accessibility and manipulability reduce the need for robot-side complexity and help identify the smallest set of feasible home changes, within realistic cost, effort and time limits, for compact single-floor homes. Description: Ph.D.(Melit.)

2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/146877 2026-05-28T11:59:22Z 2026-01-01T00:00:00Z

Title: Developing an immersive learning environment for engineering education and re-skilling, using metaverse technologies Abstract: Industry 4.0 and 5.0 demand engineers with higher-order competencies, that can be difficult to cultivate through traditional lecture-based instruction alone. Immersive technologies offer potential solutions, yet existing research has focused on single-user applications, leaving collaborative metaverse affordances relatively underexplored. The absence of structured frameworks for developing metaverse educational environments further hinders adoption. This thesis investigates metaverse-based learning environments for educational outcomes within manufacturing. The research addresses three gaps: the lack of structured frameworks, the limited exploration of how immersive technologies can support learning of complex interdependent concepts, and the underutilisation of multi-user collaborative affordances. The MITE (Metaverse Immersive Training Environment) framework was developed, integrating Design Thinking with educational models including TPACK, Constructive Alignment, and the 5E instructional model. The framework was validated through a proof-of-concept prototype targeting Quality Assurance and Process Layout Optimisation. These topics exemplify the interconnected nature of modern manufacturing yet are typically taught in isolation. The prototype integrates both disciplines within a collaborative virtual manufacturing environment, enabling realtime collaboration with complex scenarios. A comparative evaluation study compared Learning Outcomes (LOs) between those receiving the metaverse experience and traditional instruction alone. Results indicated that the metaverse group outperformed the traditional group across all measures: mean knowledge scores of 44.69 compared to 41.04 out of 60, greater confidence gains, and completion rates of 84% compared to 63%. The effect size of 0.44 exceeds the average effect of educational interventions, representing a practically significant improvement in LOs and engagement. This research contributes a replicable framework for developing metaverse-based learning environments, empirical evidence supporting immersive collaborative learning for complex engineering topics, and demonstrates the value of multi-user metaverse over single-user VR in developing teamwork and systems thinking competencies demanded by Industry 4.0 and 5.0. Description: M.Sc.(Melit.)

2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145392 2026-04-08T06:23:33Z 2026-01-01T00:00:00Z

Title: Development of a PMMA/TiO2/LO nanocomposite for aquatic environments Abstract: Structures and vessels exposed to water are susceptible to corrosion and fouling due to multiple factors such as the complex biology present in these environments. Hence, it is important that new materials are investigated, combining durability and anti-fouling properties. To tackle this, the work in this project investigated a nanocomposite material, that consisted of a polymethyl methacrylate matrix and titanium dioxide nanoparticles encasing linseed oil as the dispersed phase. The development of the material and evaluation of its durability, anti-fouling properties and leaching of ions into the environment were the main objectives of this project. Samples were prepared using the doctor blade technique, applying a film containing 8.6, 14.8 and 28.3 wt% titanium dioxide nanoparticles on to glass substrates. To assess the durability of the material, salt-spray testing was conducted to simulate environmental conditions while leaching testing was carried out in deionised water. Prior to the salt-spray testing, the weight, wettability and surface roughness of the samples were assessed. These properties were also assessed just after the salt-spray testing and after two weeks. Optical microscopy was conducted to assess the self- healing capabilities of the material. The results showed that contact angle as well as the surface roughness of the nanocomposite increased with an increase in wt% of the nanoparticles. After salt-spray testing, the contact angle decreased while the surface roughness increased. This trend continued after the two weeks were allowed to assess any self-healing. It was noted that the nanocomposite was prone to degradation as well as showing significant adherence issues. Trends towards self-healing properties were noted within the 28.3 wt% samples that underwent both salt-spray testing as well as the leaching testing, but this was not conclusive. The liquid from leaching testing was extracted and analysed using inductively coupled plasma mass spectrometry. The leaching testing indicated that the 28.3 wt% samples leached less than 1 ng/mL of titanium ions. The anti-fouling tests conducted involved assessing the growth inhibition of the nanocomposite against both marine and freshwater algae. All the samples exhibited anti-fouling properties that were not significantly different to PMMA. They showed sufficient growth inhibition against the freshwater algae while being less effective against the marine algae, showing differing results for the latter. The material developed was not durable as would be necessary for the aquatic environment. However, the nanocomposite provided good anti-fouling properties while keeping Ti ion leaching into the environment below the threshold. Description: M.Sc.(Melit.)

2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/145301 2026-04-02T10:02:39Z 2026-01-01T00:00:00Z

Title: Characterisation of hydrogen engine combustion and mitigation of knock in dual-fuel operations Abstract: Over the past decades, significant efforts have been focused on reducing fossil fuel dependency by promoting sustainable energy sources. Recently, major corporations have shifted their attention to H2 as a fuel for internal combustion engines, as the development of H2 fuel cells has not progressed as rapidly as expected. H2, with its higher calorific value and carbon-free molecular composition, offers a promising clean fuel alternative. However, the limited H2 infrastructure necessitates the continued development of dual-fuel combustion. This dissertation focuses on H2 combustion characterisation and improving the performance of existing dual-fuel engines by leveraging the thermodynamic properties of fuels. H2 combustion characterisation was performed utilising in-cylinder pressure measurements obtained through experimental testing. These in-cylinder pressure measurements were processed using LabVIEW software to analyse key combustion parameters such as the rate of heat release and combustion duration. These parameters were subsequently compared to those obtained from conventional fuels. Accurate determination of the air-fuel ratio during lean operation is critical. This was achieved through simultaneous and separate measurements of fuel and airflow rates. To address the pulsating airflow, a critical flow orifice was designed and incorporated into the setup based on choked flow theory, which depends solely on upstream conditions. The major highlight of this combustion characterisation investigation is the high brake thermal efficiency of 23% achieved by H2 under λ3 mixture, compared to the 21% obtained with stoichiometric petrol testing at wide open throttle. A cryogenic setup was developed specifically for liquid natural gas injection to enhance combustion and mitigate engine knock in dual-fuel engines. However, due to safety constraints, experimentation with liquid natural gas was substituted with injections of liquid nitrogen and liquid propane. This approach aims to reduce intake air temperatures, thereby mitigating engine knock. Temperature measurements during liquid nitrogen injection revealed a reduction of approximately 45 °C at a 60% substitution ratio with vapour propane. Liquid propane injection resulted in temperature reductions of 4 °C and 7 °C at 60% and 70% substitution ratios, respectively. Across all substitution ratios and intake conditions tested, the use of liquid dual-fuel injection consistently decreased the maximum amplitude of pressure oscillations, indicating improved knock resistance. Description: M.Sc.(Melit.)

2026-01-01T00:00:00Z