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PhD Graduates

To give an impression of what it is to be a PhD student at MESA+, we interview all finishing students and ask them to share their experiences. An abstract of their thesis’s can also be found, so that it can supply an idea of the scientific part of their work, while the interviews are intended to give an impression of the working environment of a PhD student at MESA+.

Varghese Mathai "Buoyant particles and fluid turbulence" In this thesis, first, the Lagrangian dynamics of tiny bubbles in a turbulent flow were studied. Experimental measurements of their acceleration statistics were performed. Gravity was found to induce intense accelerations even for tiny particles and bubbles in turbulence. These findings were published in Physical Review Letters. Yean-Sheng Yong "Potassium double tungstate waveguides with high ytterbium concentration for optical amplification" In this thesis rare-earth-ion-doped amplifiers were studied, being key enabling devices for modern telecommunication systems. ‘Nowadays chip-scale amplifiers are introduced,’ says Yean-Sheng Yong. ‘Rare-earth-ion-doped optical amplifiers are used in long-haul fiber optic communication systems. Paul-Christiaan Spruijtenburg "‘Imperfection, holes and defects in silicon quantum dots" In this thesis spin and charge carried by holes (typified as the absence of a single electrons) in quantum dots, is investigated. ‘We explored the origin of defects in quantum dot formation, coming about by either disorder or issues arising in fabrication,’ Paul-Christiaan Spruijtenburg says. ‘Also we devised methods of eliminating them.’ Janneke Veerbeek "Monolayer functionalization of silicon micro and nanowires: towards solar-to-fuel and sensing devices" Silicon is an attractive semiconductor, especially when taking advantage of the larger surface area of silicon micro and nanowires. This thesis aims at the formation of molecular monolayers on H-terminated silicon micro and nanowires, for solar-to-fuel and sensing devices. Bojian Xu ‘Charge transport in nanoscale lateral and vertical organic semiconductor devices’ In this thesis research charge transport in organic semiconductor devices, with different device configurations, was investigated. Two organic semiconductor materials were focused on: DXP... Roberto Floris ‘Removal of nanoparticles in drinking water treatment processes’ This thesis investigates the removal - and removal mechanisms - of engineered nanomaterials and nanoparticles in drinking water treatment plants. The potential release into aquatic environments, raises concerns... Roger Coloma Ribera ‘Growth and thermal oxidation of Ru and ZrO2 thin films as oxidation protective layers’ This thesis focuses on studying capping materials that prevent oxidation of underneath layers in several applications, for example in: microelectronics (gate dielectrics, memory devices), photovoltaics and extreme ultraviolet lithography optics... Marko van Dalfsen ‘High-power, highly-efficient thulium-doped potassium double tungstate channel waveguide lasers’ In this thesis the fabrication and characterization of compact channel waveguide lasers were central. Thulium-doped layers were grown onto undoped potassium yttrium double... Pascal Sleutel ‘Droplets: drag, coalescence and impact’ In this thesis, first of all, a stream of widely spaced high-velocity droplets was demonstrated in a novel way. ‘Studying these ultrahigh velocity droplets involved a novel experimental, numerical and theoretical approach,’... Kurt Vergeer ‘Structure and functional properties of epitaxial PbZrxTi1-xO3 films’ The work described in this thesis is focused on the characterization and understanding of epitaxial, clamped, dense PbZrxTi1-xO3 (PZT) films.
‘The main aim was to better understand these types of materials,’ Kurt Vergeer says...
Shazia Ilyas ‘Multifunctional weak polyelectrolyte multilayers for membrane applications’ In this thesis the main focus was on using weak polyelectrolyte multilayers (PEM) coatings, to fabricate multifunctional PEM based membranes for liquid applications on ultrafiltration membrane supports... Elmer van Geijn ‘Spintronic effects at nickel-graphene interfaces’ In this thesis physical phenomena, like magnetoresistance, occurring in organic spintronic devices, were studied. ‘Increasing the understanding of these... Naveen Kumar ‘Surface charge characterization of solid-liquid interfaces, using Atomic Force Microscopy’ The aim of this work is to understand scientific challenges in enhanced oil recovery (EOR). Charging behavior and ion adsorption at solid-... Sergei Sokolov ‘Dynamic tuning of photonic crystal nanocavities’ In this thesis experimental investigations and control of properties, of single and coupled photonic crystal nanocavities are presented. Photonic... Loreto Oyarte Galvez ‘Anomalous intruder response in diverse granular systems’ In this thesis three distinct granular systems with an intruder were described. ‘From various experiments, we were able to relate macroscopic behaviour to new microscopic details,’ Loreto Oyarte Galvez says. ‘In the case of a build-in rotor - immersed in a granular gas - we... Michiel van Limbeek ‘The dynamics of Leidenfrost drops’ This thesis focuses on the sudden reduction of the heat transfer rate in the context of spray cooling: a remarkable phenomenon occurring at strongly elevated plate temperatures, above the saturation temperature of the liquid spray... Yunlong Yu ‘Switchable adhesion and friction using polymer brushes’ In this thesis switchable friction and adhesion is studied. Stimulus responsive end-anchored polymers forming a brush, are used. ‘We can make smart systems, composed of polymers, that respond to... Yin Tao "Quasi high harmonic generation" In this thesis quasi-phase matching (QPM) was used in order to generate sufficient high-order harmonic generation (HHG). Here, periodic modulation of the generation process was used, enabling HHG in the in-phase regions and... Werner Wessels "Atomic force microscopy imaging growth during pulsed laser deposition" In this thesis a microscopy design is demonstrated, containing a high resonance atomic force microscopy (AFM) scanner together with high bandwidth scanning probe microscopy (SPM) electronics. ‘This is a major... Joao Crispim "Instructive materials for tendon and ligament augmentation" In this thesis the potential of using synthetic peptides is demonstrated in the design and improvement of biomaterials. Crucial in this approach are growth factors. These are hormone-like proteins, capable of stimulating... Gerard Cadafalch Gazquez "Novel functional ceramic fibers and nanochannels" In this thesis different ceramic micro- and nanomaterials were fabricated, characterized and tested. ‘We successfully combined two techniques,’ Gerard Cadafalch Gazquez says. ‘Electrospinning and sol-gel processing... Marcel ten Hove “Towards hydrothermally stable hydrogen separation membranes” In this thesis the focus is on developing hydrothermally stable microporous membranes to be used in novel water gas shift membrane reactor concepts. ‘Gas permeation properties and hydrothermal stability are by far the most... Jin Cui “Spatiotemporal electrochemical detection in nanofluidic devices” The main focus of this thesis research was to explore mass-transport processes. This was done for redox-active analytes in concentrated supporting electrolytes, when driven by external pressure through nanofluidic channels with... Edo Frederix "Eulerian modeling of aerosol dynamics" This thesis deals with aerosols: small particles or droplets in gases. In his PhD work Edo Frederix aimed at modeling aerosol dynamics, distinguishing between aerosol evolution and aerosol transport. Droplet nucleation,... Sander Haase "Transport near slippery interfaces" The aim of this thesis was to obtain further insight into the transport phenomena near slippery and/or heterogeneous interfaces.
‘Wall slip can be utilized to increase advection in the direct vicinity of a wall,’ Sander Haase...
Sahana Sarkar "‘Unconventional Electrochemistry in Nanogap Transducers" In this thesis the various ingredients to build a sensing platform for single molecule detection, have been studied. Several practical pitfalls of scaling down such sensors are discussed, and alternate solutions are provided... Mishra Kartikeya "Electrically tuneable opto-fluidic lenses: fabrication and characterization" In this thesis adaptive optofluidic lens devices with aberration control were fabricated and characterized. ‘The image captured by lenses is sometimes blur and not up-to-date,’ Kartikeya Mishra says. ‘To address this problem was the...