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Your search keyword '"van Leeuwen, Ronald"' showing total 25 results
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2. High-Q Tantalum Oxide Nanomechanical Resonators by Laser-Oxidation of TaSe2

Author

Cartamil-Bueno, Santiago J., Steeneken, Peter G., Tichelaar, Frans D., Navarro-Moratalla, Efren, Venstra, Warner J., van Leeuwen, Ronald, Coronado, Eugenio, van der Zant, Herre S. J., Steele, Gary A., and Castellanos-Gomez, Andres

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Controlling the strain in two-dimensional materials is an interesting avenue to tailor the mechanical properties of nanoelectromechanical systems. Here we demonstrate a technique to fabricate ultrathin tantalum oxide nanomechanical resonators with large stress by laser-oxidation of nano-drumhead resonators made out of tantalum diselenide (TaSe2), a layered 2D material belonging to the metal dichalcogenides. Prior to the study of their mechanical properties with a laser interferometer, we checked the oxidation and crystallinity of the freely-suspended tantalum oxide in a high-resolution electron microscope. We show that the stress of tantalum oxide resonators increase by 140 MPa (with respect to pristine TaSe2 resonators) which causes an enhancement of quality factor (14 times larger) and resonance frequency (9 times larger) of these resonators.

Published
2015
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3. Single-layer MoS2 mechanical resonators

Author

Castellanos-Gomez, Andres, van Leeuwen, Ronald, Buscema, Michele, van der Zant, Herre S. J., Steele, Gary A., and Venstra, Warner J.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

Here, we demonstrate the fabrication of single-layer MoS2 mechanical resonators. The fabricated resonators have fundamental resonance frequencies in the order of 10 MHz to 30 MHz (depending on their geometry) and their quality factor is about ~55 at room temperature in vacuum. The dynamical properties clearly indicate that monolayer MoS2 membranes are in the membrane limit (i.e., tension dominated), in contrast to their thicker counterparts, which behave as plates. We also demonstrate clear signatures of nonlinear behaviour of our atomically thin membranes, thus providing a starting point for future investigations on the nonlinear dynamics of monolayer nanomechanical resonators., Comment: Supp. Info. included

Published
2013
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5. Power Quality Measurement Results for a Configurable Urban Low-Voltage DC Microgrid

Author

van den Brom, Helko, van Leeuwen, Ronald, Maroulis, Gerasimos, Shah, Samad, and Mackay, Laurens

Subjects
Power Quality, Ripple, DC microgrid, LVDC grids
Abstract

The growing use of renewable energy sources and sustainable technologies has increased the attractiveness of low-voltage DC distribution grids. Despite initial research and standardization work, the definition of power quality (PQ) issues and their related compatibility levels in DC grids and the related measurement techniques remain in their infancy. The lack of available measurement results obtained in real-world situations is a major shortcoming. In this paper, the results of a measurement campaign obtained in a configurable bipolar 350 V/700 V DC microgrid in an urban environment are presented. Voltage and current signals were registered continuously at different positions in the microgrid with a sampling rate of 500 kSa/s while changing the configuration of the microgrid; the resulting data were analyzed afterwards, with a focus on DC voltage and current variation, ripple, and spectral analysis. The measurements were taken with custom-designed metrology-sound measurement equipment. The measurement results provide input to the development of DC PQ analysis tools and the standardization of DC PQ measurement methods. Furthermore, the experience obtained will be beneficial for utility companies and regulatory authorities for reliable planning-level and compatibility-level surveys.

Published
2023

7. EMC Testing of Electricity Meters Using Real-World and Artificial Current Waveforms

Author

van den Brom, Helko E., primary, van Leeuwen, Ronald, additional, Marais, Zander, additional, ten Have, Bas, additional, Hartman, Tom, additional, Azpurua, Marco, additional, Pous, Marc, additional, Kok, Gertjan, additional, van Veghel, Marijn, additional, Kolevatov, Ilia, additional, Malmbekk, Helge, additional, Silva, Ferran, additional, and Leferink, Frank, additional

Published
2021
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8. EMC testing of electricity meters using real-world and artificial current waveforms

Author

Universitat Politècnica de Catalunya. Departament d'Enginyeria Electrònica, Universitat Politècnica de Catalunya. IEB - Instrumentació Electrònica i Biomèdica, Van Den Brom, H.E., ten Have, Bas, Hartman, Tom, Azpúrua Auyanet, Marco Aurelio, Pous Solà, Marc, Silva Martínez, Fernando, Leferink, F., van Leeuwen, Ronald, Marais, Zander, Kok, Gertjan J. P., van Veghel, Marijn G. A., Kolevatov, Ilia, Malmbekk, Helge, Universitat Politècnica de Catalunya. Departament d'Enginyeria Electrònica, Universitat Politècnica de Catalunya. IEB - Instrumentació Electrònica i Biomèdica, Van Den Brom, H.E., ten Have, Bas, Hartman, Tom, Azpúrua Auyanet, Marco Aurelio, Pous Solà, Marc, Silva Martínez, Fernando, Leferink, F., van Leeuwen, Ronald, Marais, Zander, Kok, Gertjan J. P., van Veghel, Marijn G. A., Kolevatov, Ilia, and Malmbekk, Helge

Abstract

In 2015, the energy measurement of some static electricity meters was found to be sensitive to specific conducted electromagnetic disturbances with very fast current changes caused by highly nonlinear loads, leading to meter errors up to several hundred percent. This article describes new results on the electromagnetic compatibility (EMC) of 16 different meters from all over Europe when exposed to real-world disturbance signals. Those test signals were obtained from household appliances and onsite measurements at metered supply points all over Europe. The results show that also the interference signals recorded onsite can cause measurement errors as large as several hundred percent, even for meters that pass the present EMC standards. This unambiguously demonstrates that the present immunity testing standards do not cover the most disturbing conducted interference occurring in present daily-life situations due to the increased use of nonlinear electronics. Furthermore, to enable the adoption of potential new test waveforms in future standards for electricity meter testing, artificial test waveforms were constructed based on real-world waveforms using a piece-wise linear model. These artificial test waveforms were demonstrated to cause meter errors similar to those caused by the original real-life waveforms they are representing, showing that they are suitable candidates for use in improved standardization of electricity meter testing., Postprint (published version)

Published
2021

22. Single-Layer MoS2Mechanical Resonators

Author

Castellanos-Gomez, Andres, primary, van Leeuwen, Ronald, additional, Buscema, Michele, additional, van der Zant, Herre S. J., additional, Steele, Gary A., additional, and Venstra, Warner J., additional

Published
2013
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