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De Visser, P.J. (author)
This thesis describes the intrinsic limits of superconducting microresonator detectors. In a superconductor at low temperature, most of the electrons are paired into so called Cooper pairs, which cause the well-known electrical conduction without resistance. Superconducting microwave resonators have therefore very high quality factors and are...
doctoral thesis 2014
document
Vuorinen, V. (author), Yu, J. (author), Tirunagari, S. (author), Kaario, O. (author), Larmi, M. (author), Duwig, C. (author), Boersma, B.J. (author)
Large-eddy simulations (LES) based on scale-selective implicit filtering are carried out in order to study the effect of nozzle pressure ratios on the characteristics of highly underexpanded jets. Pressure ratios ranging from 4.5 to 8.5 with Reynolds numbers of the order 75?000–140?000 are considered. The studied configuration agrees well with...
journal article 2013
document
Sun, Z. (author), Schrijer, F.F.J. (author), Scarano, F. (author), Van Oudheusden, B.W. (author)
The three-dimensional instantaneous flow organization in the near wake of a micro-ramp interacting with a Mach 2.0 supersonic turbulent boundary layer is studied using tomographic particle image velocimetry. The mean flow reveals a wake with approximately circular cross section dominated by a pair of counter-rotating streamwise vortices...
journal article 2012
document
Hayton, D.J. (author), Gao, J.R. (author), Kooi, J.W. (author), Ren, Y. (author), Zhang, W. (author), De Lange, G. (author)
We report on a method to stabilize a hot electron bolometer (HEB) mixer at 2.5 THz. The technique utilizes feedback control of the local oscillator (LO) laser power by means of a swing-arm actuator placed in the optical beam path. We demonstrate that this technique yields a factor of 50 improvement in the spectroscopic Allan variance time which...
journal article 2012
document
Bedeaux, D. (author), Ortiz de Zárate, J.M. (author), Pagonabarraga, I. (author), Sengers, J.V. (author), Kjelstrup, S. (author)
In this paper, we consider a simple reaction-diffusion system, namely, a binary fluid mixture with an association-dissociation reaction between two species. We study fluctuations at hydrodynamic spatiotemporal scales when this mixture is driven out of equilibrium by the presence of a temperature gradient, while still being far away from any...
journal article 2011
document
Kenjeres, S. (author)
Motivated by the concept of interdependency of turbulent flow and electromagnetic fields inside the spiraling galaxies, we explored the possibilities of generating a localized Lorentz force that will produce a three-dimensional swirling flow in weakly conductive fluids. Multiple vortical flow patterns were generated by combining arrays of...
journal article 2011
document
Kotsonis, M. (author), Veldhuis, L. (author)
An experimental investigation is performed on the operation of dielectric barrier discharge plasma actuators used as manipulators of secondary and unsteady flow structures such as boundary layer instabilities or shedding vortices. The actuators are tested mainly in pulse mode. High sample rate hot-wire measurements of the induced velocity field...
journal article 2010
document
Amiri-Simkooei, A. (author), Snellen, M. (author), Simons, D.G. (author)
A method has recently been developed that employs multi-beam echo-sounder backscatter data to both obtain the number of sediment classes and discriminate between them by applying the Bayes decision rule to multiple hypotheses [ Simons and Snellen, Appl. Acoust. 70, 1258–1268 (2009) ]. In deep water, the number of scatter pixels within the beam...
journal article 2009
document
Prins, F. (author), Hayashi, T. (author), De Vos van Steenwijk, B.J.A. (author), Gao, B. (author), Osorio, E.A. (author), Muraki, K. (author), Van der Zant, H.S.J. (author)
We present a method to make Pt nanometer-spaced electrodes that are free of metallic particles and stable at ambient conditions. The nanogaps are fabricated using feedback-controlled electromigration to form few-atom contacts. When performing this procedure at elevated temperatures (>420?K), the Pt contacts undergo self-breaking so that...
journal article 2009
document
Van Reeuwijk, M. (author), Jonker, H.J.J. (author), Hanjali?, K. (author)
Using a symmetry-accounting ensemble-averaging method, we have identified the wind in unbounded Rayleigh–Bénard convection. This makes it possible to distinguish the wind from fluctuations and to identify dynamic features of each. We present some results from processing five independent three-dimensional direct numerical simulations of a ? = 4...
journal article 2005
document
Blanckaert, K. (author), De Vriend, H.J. (author)
In spite of its importance, little is known about the turbulence characteristics in open-channel bends. This paper reports on an experimental investigation of turbulence in one cross section of an open-channel bend. Typical flow features are a bicellular pattern of cross-stream circulation (secondary flow) and a turbulence activity in the outer...
journal article 2005
document
Senthilkumar, K. (author), Grozema, F.C. (author), Bickelhaupt, F.M. (author), Siebbeles, L.D.A. (author)
Values of charge transfer integrals, spatial overlap integrals and site energies involved in transport of positive charges along columnar stacked triphenylene derivatives are provided. These parameters were calculated directly as the matrix elements of the Kohn–Sham Hamiltonian, defined in terms of the molecular orbitals on individual...
journal article 2003
document
Bakker, A.F. (author), Lowe, C.P. (author)
In a suspension, the hydrodynamic interactions between particles can propagate by two mechanisms: relatively slowly, by the diffusion of transverse momentum, or relatively rapidly, by the propagation of sound waves. Here we describe computer simulation results for the collective and single particle dynamics of colloidal particles with the aim of...
journal article 2002
document
Li, Y. (author), McLaughlin, J.B. (author), Kontomaris, K. (author), Portela, L. (author)
This paper presents results for the behavior of particle-laden gases in a small Reynolds number vertical channel down flow. Results will be presented for the effects of particle feedback on the gas-phase turbulence and for the concentration profile of the particles. The effects of density ratio, mass loading, and particle inertia will be...
journal article 2001
document
Tsinober, A. (author), Vedula, P. (author), Yeung, P.K. (author)
The properties of acceleration fluctuations in isotropic turbulence are studied in direct numerical simulations (DNS) by decomposing the acceleration as the sum of local and convective contributions (aL = ?u/?t and aC = u??u), or alternatively as the sum of irrotational and solenoidal contributions [aI = ??(p/?) and aS = ??2u]. The main emphasis...
journal article 2001
document
Woeltgens, P.J.M. (author), Dekker, C. (author), Gielkens, S.W.A. (author), De Wijn, H.W. (author)
conference paper 1993
document
Liefrink, F. (author), Scholten, A.J. (author), Dekker, C. (author), Dijkhuis, J.I. (author), Alphenaar, B.W. (author), Van Houten, H. (author), Foxon, C.T. (author)
journal article 1992
document
Liefrink, F. (author), Scholten, A.J. (author), Dekker, C. (author), Dijkhuis, J.I. (author), Eppenga, R. (author), Van Houten, H. (author), Foxon, C.T. (author)
conference paper 1992
document
Liefrink, F. (author), Scholten, A.J. (author), Dekker, C. (author), Eppenga, R. (author), Van Houten, H. (author), Foxon, C.T. (author)
journal article 1991
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