• von Karman Institute for Fluid Dynamics

    Online Info Session dedicated to US Students
    9 April 2024 - 6PM (Brussels CEST)
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  • von Karman Institute for Fluid Dynamics

    Education in Research through Research


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  • von Karman Institute for Fluid Dynamics

    Education in Research through Research


    Read More

  • von Karman Institute for Fluid Dynamics

    Education in Research through Research


    Read More

  • von Karman Institute for Fluid Dynamics

    Education in Research through Research


    Read More

  • von Karman Institute for Fluid Dynamics

    Education in Research through Research


    Read More

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PhD Public Defense of Imre Tamás Horváth / ULB 20 October 2015 / 04:00PM

The PhD public defense of Imre Tamás Horváth will take place on the 20th October at 4:00PM at the Université Libre de Bruxelles (ULB).

Thesis summary

The purpose of my phd studies was to develop and apply an experimental technique for measuring the size of nanoparticles and nanodroplets in a flow environment. The developed non-intrusive, optical method is called Light Extinction Spectroscopy (LES) and it allows to determine the size of particles from measuring their light transmission spectrum on the Ultraviolet-Near-Infrared range. The most crucial part of the development work was to obtain a reliable data processing method, which is based on the regularized solution of an ill-conditioned inverse problem. The developed method was first tested using synthetic data, which allowed to determine the measurement range and also the measurement errors caused by various sources. This was followed by performing laboratory experiments for validating the LES technique. Validation measurements using calibrated particles and a reference instrument showed that sizing errors are in the order of 5-10%. Afterwards, the technique was applied for characterizing the Brownian coagulation process of nanodroplets, where the growth of droplets was successfully measured and was found to agree with theoretical expectations. Next, the LES technique was applied to coagulating solid particles, where the growth rate of these complex non-spherical objects was retrieved. Finally, a particle monolayer was deposited on an air-water interface and it was found that the LES technique can retrieve the particle-water contact angle, which allows the characterization of nanoparticle wettability and the study of the related interesting physical phenomena.