Inductively coupled plasma reactive ion etching of high aspect ratio structures on 4H-SiC for MEMS applications

As silicon carbide(SiC) gets more and more attention from the semiconductor industry due to its robust mechanical and chemical properties, reliable and standardized processing technologies such as reactive ion etching(RIE) for SiC are in great demand. This is because of the difficulty and challenge of fabricating micro devices on the SiC...

Aerodynamic Design Integration of Strut Braced Wings

Due to the high aspect ratio and low induced drag of aircraft with strut-braced wings, they are being extensively studied due to their fuel-saving potential. This thesis aims to expand the fundamental knowledge in the design of aircraft with Strut Braced Wings (SBW) by achieving the following objectives. <br/><br/>The objectives of this thesis...

Effect of Substrate Concentration & Elevated CO2 Partial Pressure on the Odd & Even Carboxylate Formation

Of all the greenhouse gases (GHGs), carbon dioxide (CO2) has been the target of most climate recovery efforts as it is the most abundantly emitted GHG by mass. In fact, in 2015 a legally binding international treaty was adopted by 196 parties in Paris, France to constrain the anthropogenic warming to 1.5-2.0˚C above the pre-industrial level. In...

Breaking the Curse of Dimensionality: Polynomial Chaos for Exploratory Modelling

In light of worsening climate change and an increased interest in adapting infrastructure to cope with its effects, model-based decision support has become an essential tool for policy makers. In conditions of deep uncertainty, models may be used to explore a large space of possible system behaviours and so encourage a wider consideration of the...

Assessing the drivability of a monopile through the rock armour layer: An analysis using Discrete Element Method and small-scale testing

Deployment of renewable energy is essential to reach a carbon neutral economy. Offshore wind farms have caught the interest of many developed countries since they are an essential source of green energy. The interest of this thesis lays in the design of the foundation used for offshore wind farms, in particular the interaction between the...

Feasibility of seasonal storage of green gas in Dutch geological formations

In a world with growing energy consumption, and concerns over climate quality, new ways of producing and storing clean energy is more relevant than ever. Storing ‘green’ gas (e.g. methane) is a new concept building on well-established fundamentals. Using renewable energy, through electrochemical processes (i.e. electrolysis), hydrogen is first...

Improving Industrial Solar Cell Fabrication using Neural Networks and Genetic Algorithms

The present thesis approaches the improvement of the performance metrics of industrially fabricated solar cells. It aims to develop an optimization method that uses machine learning to identify an improved configuration of solar cell production lines. Conventional methods for process improvement rely on modelling experimental data to improve a...

Prognostics-driven supply chain optimization in commercial aviation

Maintenance providers in commercial aviation are looking into new strategies to improve maintenance operations and aircraft availability in order to reduce cost and increase customer satisfaction. Aircraft availability and thus profitability highly relies on adequate maintenance because an aircraft is only profitable when...

Systematic Design Optimization of grabs handling cohesive bulk materials: Systematisch ontwerp optimalisatie van overslag grijpers voor cohesive bulk materialen

Grabs are often used for unloading bulk carriers that transport iron ore cargoes around the globe. The unloading process is time-consuming, and terminals strive to maximise their turnover capacity. Grab performance is a combination of maximum crane capacity, grab design and bulk material behaviour. Due to bulk uncertainties occurred by varying...

Experimental and numerical research into propeller thrust breakdown due to ventilation

When propellers are operating near the free surface,  phenomenon called ventilation might occur. Due to insufficient immersion and high thrust loading, the propeller draws air, resulting in a reduced thrust. Reduced thrust may have consequences such as loss of propulsive power, control and steerability, and may therefore be...

Data - driven design of a metamaterial unit cell using sparse Gaussian processes

Metamaterials are a new class of materials where the properties crucially depend on the design of the unit cell that is periodically repeated in space. In this study a new metamaterial unit cell concept has been proposed, inspired by a class of space structures known as deployable masts. The ability of these structures to contract to a fraction...

Integration and optimisation of a novel industrial Fused Composite Manufacturing process for prepreg filament

Since the aerospace industry is continuously looking for new strong and lightweight solutions to existing aircraft parts, Fused Composite Manufacturing has much potential for future applications as it incorporates both the freedom of design and a continuous fiber reinforcement. The current state of the technology is of low maturity as...

A Framework for 'Smart' Computational Micromechanics

More than half a century after the first application of composite materials in aircraft, the accurate prediction of their failure remains a pressing and unresolved issue. Another important limitation continues to be the low transverse strength of unidirectional composite plies, which can lead to premature failure in common laminates such as the...

Super-growth of CNTs based on ZrN for TSV application

This thesis has explored the possibility of using carbon nanotubes (CNT) as a novel material for through-silicon vias (TSV) in 3D-integrated circuits. With the steady downscaling trend of the semiconductor industry, a major limiting factor to the overall performance of the device is the delay from interconnects; a trend that is worsening over...