597 research outputs found
Marcel Hoebeke
No full textGoossens Jan. Marcel Hoebeke. In: Bulletin de la Commission royale d'histoire. Académie royale de Belgique. Tome 175, 2009. pp. 119-124
Marcel Hoebeke
No full textGoossens Jan. Marcel Hoebeke. In: Bulletin de la Commission royale d'histoire. Académie royale de Belgique. Tome 175, 2009. pp. 119-124
Roger Goossens :portrait d'un poète
No full textDenis Marion est le pseudonyme de Marcel Defosseinfo:eu-repo/semantics/publishe
Nano particles play with electrons: Fundamental research into electron transport inside dye-sensitised solar cells
No full textWere stuck with a chicken-and-egg-problem: solar cells are expensive, so they dont get sold, which keeps the production volume low, so the price remains high.However, within a decade the price of electricity from a solar panel will be comparable to that of conventional mains power, says Dr. Albert Goossens, associate professor at the laboratory for Inorganic Chemistry at tu delft.He is currently investigating new methods and, in particular, new materials, that will render the production of electricity from solar energy more efficient. The special focus is on the Graetzel cell, a solar cell based on titanium dioxide (TiO2). Measurements of the speed of electrons led Goossens to the surprising conclusion that titanium dioxide nano particles behave like quantum dots
Appendices_online_supp – Supplemental material for Summarizing Patient Preferences for the Competitive Landscape of Multiple Sclerosis Treatment Options
No full textSupplemental material, Appendices_online_supp for Summarizing Patient Preferences for the Competitive Landscape of Multiple Sclerosis Treatment Options by Marcel F. Jonker, Bas Donkers, Lucas M.A. Goossens, Renske J. Hoefman, Lea J. Jabbarian, Esther W. de Bekker-Grob, Matthijs M. Versteegh, Gerard Harty and Schiffon L. Wong in Medical Decision Making</p
Total resonant absorption of acoustic-oscillations in sunspots
No full textThe question of total resonant absorption of acoustic oscillations in sunspots is studied for cylindrical 1-D flux tubes that are stratified only in the radial direction and surrounded by a uniform, non-magnetic plasma. The numerical investigation of Goossens and Poedts (1992) in linear resistive MHD is taken further by increasing the strength of the azimuthal magnetic field in the equilibrium flux tubes. For relatively strong azimuthal magnetic fields, total absorption is found over a relatively wide range of spot radii.status: Publishe
Cross-sectional area and intensity variations of sausage modes
No full textThe observations obtained using the Rapid Oscillations in the Solar Atmosphere instrument (ROSA) show variations in both cross-sectional area and intensity for magnetic pores in the photosphere. We aim to determine the wave mode by looking at the phase difference between the cross-sectional area and intensity variations. We used a straight cylinder as a model for the flux tube. The plasma is uniform both inside and outside the flux tube with a possible jump in the equilibrium values at the boundary, the magnetic field is directed along the flux tube. We derived analytic expressions for the cross-sectional area variation and the total intensity variation. Using these analytic expressions, we calculated the phase differences between the cross-sectional area and the intensity variations. These phase differences were then used to identify the wave mode. We found that for slow sausage modes the cross-sectional area and intensity variations are always in phase, while for fast sausage modes the variations are in antiphase.sponsorship: Odysseus programme of the FWO-Vlaanderen.
EU's Framework Programme 7 as an ERG with grant number 276808.
Interuniversity Attraction Poles Programme initiated by the Belgian Science Policy Office (IAP P7/08 CHARM).
Marcel Goossens acknowledges GOA/2009-09.status: Publishe
9_Appendix.rjf_online_supp – Supplemental material for The Fold-in, Fold-out Design for DCE Choice Tasks: Application to Burden of Disease
No full textSupplemental material, 9_Appendix.rjf_online_supp for The Fold-in, Fold-out Design for DCE Choice Tasks: Application to Burden of Disease by Lucas M. A. Goossens, Marcel F. Jonker, Maureen P. M. H. Rutten-van Mölken, Melinde R. S. Boland, Annerika H. M. Slok, Philippe L. Salomé, Onno C. P. van Schayck, Johannes C. C. M. in ‘t Veen, Elly A. Stolk and Bas Donkers in Medical Decision Making</p
New insights on accretion in supergiant fast X-ray transients from XMM-Newton and INTEGRAL observations of IGR J17544-2619
No full textXMM–Newton observations of the supergiant fast X-ray transient IGR J17544?2619 are reported and placed in the context of an analysis of archival INTEGRAL/IBIS data that provide a refined estimate of the orbital period at 4.9272?±?0.0004?d. A complete outburst history across the INTEGRAL mission is reported. Although the new XMM–Newton observations (each lasting ?15 ks) targeted the peak flux in the phase-folded hard X-ray light curve of IGR J17544?2619, no bright outbursts were observed, the source spending the majority of the exposure at intermediate luminosities of the order of several 1033?erg?s?1 (0.5–10 keV) and displaying only low level flickering activity. For the final portion of the exposure, the luminosity of IGR J17544?2619 dropped to ?4?×?1032?erg?s?1 (0.5–10 keV), comparable with the lowest luminosities ever detected from this source, despite the observations being taken near to periastron. We consider the possible orbital geometry of IGR J17544?2619 and the implications for the nature of the mass transfer and accretion mechanisms for both IGR J17544?2619 and the supergiant fast X-ray transients (SFXTs) population. We conclude that accretion under the ‘quasi-spherical accretion’ model provides a good description of the behaviour of IGR J17544?2619 and suggests an additional mechanism for generating outbursts based upon the mass accumulation rate in the hot shell (atmosphere) that forms around the neutron star under the quasi-spherical formulation. Hence, we hope to aid in explaining the varied outburst behaviours observed across the SFXT population with a consistent underlying physical model
Selective spatial damping of propagating kink wavesto resonant absorption
No full textThere is observational evidence of propagating kink waves driven by photospheric motions. These disturbances, interpreted as kink magnetohydrodynamic (MHD) waves are attenuated as they propagate upwards in the solar corona. In this paper we show that resonant absorption provides a simple explanation to the spatial damping of these waves. Kink MHD waves are studied using a cylindrical model of solar magnetic flux tubes which includes a non-uniform layer at the tube boundary. Assuming that the frequency is real and the longitudinal wavenumber complex, the damping length and damping per wavelength produced by resonant absorption are analytically calculated. The damping length of propagating kink waves due resonant absorption is a monotonically decreasing function of frequency. For kink waves with low frequencies the damping length is exactly inversely proportional to frequency and we denote this as the TGV relation. When moving to high frequencies the TGV relation continues to be an exceptionally good approximation of the actual dependency of the damping length on frequency. This dependency means that resonant absorption is selective as it favours low frequency waves and can efficiently remove high frequency waves from a broad band spectrum of kink waves. It is selective as the damping length is inversely proportional to frequency so that the damping becomes more severe with increasing frequency. This means that radial inhomogeneity can cause solar waveguides to be a natural low-pass filter for broadband disturbances. Hence kink wave trains travelling along, e.g., coronal loops, will have a greater proportion of the high frequency components dissipated lower down in the atmosphere. This could have important consequences with respect to the spatial distribution of wave heating in the solar atmospher
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