Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailLateral inhibition in visual cortex of migraine patients between attacks
Coppola, Gianluca; Parisi, Vincenzo; Di Lorenzo, Cherubino et al

in Journal of Headache & Pain (2013), 14

Detailed reference viewed: 24 (1 ULg)
Full Text
Peer Reviewed
See detailLateral Magnetic Near-Field Imaging of Plasmonic Nanoantennas With Increasing Complexity
Denkova, D.; Verellen, N.; Silhanek, Alejandro ULg et al

in Small : Nano Micro (2014)

The design of many promising, newly emerging classes of photonic metamaterials and subwavelength confinement structures requires detailed knowledge and understanding of the electromagnetic near-field ... [more ▼]

The design of many promising, newly emerging classes of photonic metamaterials and subwavelength confinement structures requires detailed knowledge and understanding of the electromagnetic near-field interactions between their building blocks. While the electric field distributions and, respectively, the electric interactions of different nanostructures can be routinely measured, for example, by scattering near-field microscopy, only recently experimental methods for imaging the magnetic field distributions became available. In this paper, we provide direct experimental maps of the lateral magnetic near-field distributions of variously shaped plasmonic nanoantennas by using hollow-pyramid aperture scanning near-field optical microscopy (SNOM). We study both simple plasmonic nanoresonators, such as bars, disks, rings and more complex antennas. For the studied structures, the magnetic near-field distributions of the complex resonators have been found to be a superposition of the magnetic near-fields of the individual constituting elements. These experimental results, explained and validated by numerical simulations, open new possibilities for engineering and characterization of complex plasmonic antennas with increased functionality. [less ▲]

Detailed reference viewed: 71 (5 ULg)
Full Text
See detailA Lateral sensor for the alignment of two formation-flying satellites
Roose, Stéphane ULg; Stockman, Yvan ULg; Sodnik, Zoran

in Lehmann, Peter H.; Osten, Wolfgang; Albertazzi, Armando (Eds.) SPIE Proceedings Vol. 8788: (2013, May 15)

The lateral sensor is a system able to measure the lateral position between two satellites. It bridges the gap between the alignment accuracy achieved with the radio frequency metrology, and the alignment ... [more ▼]

The lateral sensor is a system able to measure the lateral position between two satellites. It bridges the gap between the alignment accuracy achieved with the radio frequency metrology, and the alignment accuracy required to start the high-precision optical metrology (fine-lateral and longitudinal sensor). This project concerns the demonstration of formation flying technologies for future European scientific and application missions of the EUROPEAN SPACE AGENCY. Technological developments enabling formation flying have already been initiated and some precursor missions already cover part of the related technologies, for example SMART-2. The lateral sensor developed at Centre Spatial de Liège (CSL) is based on a camera (CMOS detector) a telecentric lens designed at CSL, a fibre-coupled laser-diode bar and a corner cube. The fibre-coupled laser-diode bar emits a diverging beam, from the master spacecraft to a slave spacecraft. A corner cube located on the slave spacecraft sends the light back. This light is captured by the telecentric lens and camera (build by Deltatec Liège-B). A lateral shift “d” of the corner cube is seen on the camera as an image displacement. Real time centroidisation algorithms will allow tracking the image position and feed the on-board computer with this information via a RS422 link, allowing further position stabilisation. The imaging system needs to operate in a depth of field from 25 m to 250 m. Because of the large depth of operation, all lateral system performances are angular ones. The system is build to meet: • Tracking capability for a spot moving @ 0.5 arcdeg/sec • Spot detection with the sun in the field of view • Centroidisation accuracy: 0.1 camera pixels (3.5 arcsec) • Absolute calibration accuracy: 0.14 camera pixels (5 arcsec) In order to comply with these requirements, the following features were implemented : • The camera allows quick read-out of sub-windows of interest (in 1 ms). • Optimize radiometric budget and laser diode power consumption, and its related heat dissipation. • An interference filter blocks all unwanted light centred on the laser wavelength (980 nm). • The detector captures the images. An electronic unit records the images and localizes the bright spot (return image from the corner cube). • Implementation of a “slow detection mode”, which allows to discriminate sun from moving image The system is a standalone unit. Once connected to an unregulated 28V power-supply, it delivers, after spot detection, pixel coordinates to the RS422 link at a 10 Hz rate. Its average power consumption is 8W. The system can be put in a programming mode, to allow uploading settings in the FPGA. Tracking, absolute calibration, resolution and sun avoidance have been measured in a field of 10 arcdeg and the range of depth of 5 m to 80 m. The coarse lateral sensor has successfully undergone thermal qualification (40°C and -30 °C), and vibration test (high-level sinus, random and shock test in the 3–axis). Its metrology performances (centroidisation accuracy (<0.1 pixel RMS) and tracking) remained unchanged after these qualification tests. The absolute calibration is 0.3% in the interval of ±5arcdeg (11 arcsec in ±1arcdeg). [less ▲]

Detailed reference viewed: 58 (2 ULg)
Full Text
See detailA LATERAL SENSOR FOR THE ALIGNMENT OF TWO FORMATION-FLYING
Roose, Stéphane ULg; Stockman, Yvan ULg

Conference (2013, May 30)

The coarse lateral sensor is a system able to measure the lateral position between two satellites. It bridges the gap between the alignment accuracy achieved with the radio frequency metrology, and the ... [more ▼]

The coarse lateral sensor is a system able to measure the lateral position between two satellites. It bridges the gap between the alignment accuracy achieved with the radio frequency metrology, and the alignment accuracy required the highprecision optical metrology (fine-lateral and longitudinal sensor). The coarse lateral sensor developed at Centre Spatial de Liège (CSL) is a standalone unit. Once connected to an unregulated 28V power-supply, it delivers, the lateral position of a corner cube retro-reflector (within an angle of 10 arcdeg and from 25 to 250 m) and tracks this position at a rate of 10 Hz. The system is operational with the sun in its fieldof- view. Real time centroidisation algorithms allow tracking the image position and feed the on-board computer with this information via a RS422 link, allowing further position stabilization. The coarse lateral sensor has successfully undergone thermal qualification (40°C and -30 °C), and vibration test (high-level sinus, random and shock test in the 3– axis). [less ▲]

Detailed reference viewed: 48 (0 ULg)
Full Text
Peer Reviewed
See detailLateral structures of thin films of ampholytic diblock copolymers adsorbed from dilute aqueous solution at the solid/liquid Interface
Walter, H.; Muller-Buschbaum, P.; Gutmann, J. S. et al

in Langmuir (1999), 15(20), 6984-6990

The lateral structures of dried thin films of the ampholytic diblock copolymer poly((methacrylic acid)-block-((dimethylamino)ethyl methacrylate)) adsorbed from dilute aqueous solution onto silicon ... [more ▼]

The lateral structures of dried thin films of the ampholytic diblock copolymer poly((methacrylic acid)-block-((dimethylamino)ethyl methacrylate)) adsorbed from dilute aqueous solution onto silicon substrates were investigated by scanning force microscopy (SFM) and diffuse X-ray scattering. The adsorbed amount of polymer, as a function of pH, reveals a maximum near the isoelectric point (IEP) of the polyampholyte. Different lateral structures are determined for samples adsorbed at pH values above the maximum of the adsorbed amount, as compared to the ones adsorbed at pH values below this maximum. At a pH around the IEP, the polyampholyte precipitates and the layers are formed by adsorption of flocks with sizes in the micrometer range. Lateral structures measured by SFM are similarly detected by diffuse X-ray scattering. The later technique delivers a statistical description of the lateral surface structures averaged over a larger area. The structures investigated are related to the polyampholyte structure in solution and can be explained by the interplay of the electrostatic interactions of the two oppositely charged blocks of the polyampholyte and the charged surface, as well as by the dependencies of charge densities on pH. [less ▲]

Detailed reference viewed: 10 (1 ULg)
See detailLateral Torsional Buckling of Steel I-Beams in Case of Fire - Numerical Modeling
Vila Real, P. M. M.; Franssen, Jean-Marc ULg

in Proceedings of the 1st International Structures in Fire Workshop (2000)

Detailed reference viewed: 15 (1 ULg)
Full Text
Peer Reviewed
See detailLateral Torsional Buckling of Steel I-Beams in Case of Fire – Numerical Modelling
Vila Real, paulo; Franssen, Jean-Marc ULg

in Franssen, Jean-Marc (Ed.) Proc. 1rst int. Structures in Fire workshop (2000, June)

Detailed reference viewed: 14 (2 ULg)
Full Text
Peer Reviewed
See detailLateral torsional buckling resistance of web-tapered I-beams under linear bending moments
Vandermeulen, T.; Jaspart, Jean-Pierre ULg; Boissonnade, N.

in Proceedings of the 5th International Conference on Advances in Steel Structures (2007)

Detailed reference viewed: 68 (1 ULg)
Full Text
Peer Reviewed
See detailLateral-torsional buckling of carbon steel and stainless steel beams subjected to combined end moments and transverse loads in case of fire
Lopes, Nuno; Vila Real, Paulo; Da Silva, Luis et al

in Kodur, Venkatesh; Franssen, Jean-Marc (Eds.) Structures in Fire. Proceedings of the Sixth International Conference (2010)

This paper presents a numerical study on the behaviour of carbon steel and stainless steel I-beams subjected to lateral-torsional buckling (LTB) in case of fire. The main motivation for this work is the ... [more ▼]

This paper presents a numerical study on the behaviour of carbon steel and stainless steel I-beams subjected to lateral-torsional buckling (LTB) in case of fire. The main motivation for this work is the fact that part 1-2 of Eurocode 3 (EC3) does not take into consideration the beneficial effect, resulting from the reduction of the plastic zones connected with non-uniform bending diagrams along the beam. Although new formulae for the LTB, that approximate better the real behaviour of steel structural elements in case of fire, have been proposed in previous works, they still do not considered the combination of end moments and transverse loads, as it is stated in part 1-1 of EC3. Therefore, in this paper numerical simulations, of steel beams with combined end moments and transverse loads, are compared with the LTB design curves of EC3, and new correction factors that improve these curves are presented. [less ▲]

Detailed reference viewed: 75 (2 ULg)
Full Text
See detailLateral-torsional Buckling of Ferritic Stainless Steel Beams in Case of Fire
Lopes, Nuno; Vila Real, Paulo; Da Silva, Luis et al

in Proceedings of the first International Conference on the Art of Resisting Extreme Natural Forces (2007, July 12)

This work presents a numerical study of the behaviour of ferritic stainless steel Ibeams subjected to lateral-torsional buckling and compares the obtained results with the beam design curves of Eurocode 3 ... [more ▼]

This work presents a numerical study of the behaviour of ferritic stainless steel Ibeams subjected to lateral-torsional buckling and compares the obtained results with the beam design curves of Eurocode 3. New formulae, for the lateraltorsional buckling, that approximate better the real behaviour of ferritic stainless steel structural elements in case of fire are proposed. These new formulae were based on numerical simulations using the program SAFIR, which was modified to take into account the material properties of the stainless steel. [less ▲]

Detailed reference viewed: 26 (1 ULg)
Full Text
Peer Reviewed
See detailLateral-torsional buckling of stainless steel I-beam in case of fire
Vila Real, P. M. M.; Lopes, N.; Simoes da Silva, L. et al

in Journal of Constructional Steel Research (2008), 64

This work presents a numerical study of the behaviour of stainless steel I-beams subjected to lateral–torsional buckling in case of fire and compares the obtained results with the beam design curves of ... [more ▼]

This work presents a numerical study of the behaviour of stainless steel I-beams subjected to lateral–torsional buckling in case of fire and compares the obtained results with the beam design curves of Eurocode 3. New formulae for lateral–torsional buckling, that approximate better the real behaviour of stainless steel structural elements in case of fire are proposed. These new formulae were based on numerical simulations using the program SAFIR, which was modified to take into account the material properties of the stainless steel. [less ▲]

Detailed reference viewed: 97 (2 ULg)
Peer Reviewed
See detailLateral-torsional buckling of Stainless steel I-beams in case of fire
Vila Real, Paulo; Lopes, Nuno; Da Silva, Luis et al

Conference (2007, November 27)

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
See detailLateral-torsional buckling of unrestrained steel beams under fire conditions: Improvement of EC3 proposal
Vila Real, Paulo; Lopes, Nuno; da Silva, Luis Simoes et al

in Computers & Structures (2004), 82

The final draft of the EN version of part 1.1 of Eurocode 3 has introduced significant changes in the evaluation of the lateral-torsional buckling resistance of unrestrained beams at room temperature that ... [more ▼]

The final draft of the EN version of part 1.1 of Eurocode 3 has introduced significant changes in the evaluation of the lateral-torsional buckling resistance of unrestrained beams at room temperature that reduce the over-conservative approach of ENV 1993-1-1 in the case of non-uniform bending. Numerical modelling of the lateral-torsional buckling of steel beams at elevated temperature has shown that the beam design curve from prEN 1993-1-2 is over-conservative for loadings other than uniform bending. In line with the safety format of the lateral-torsional buckling code provisions for cold design, an alternative proposal for rolled sections or equivalent welded sections subjected to fire is presented in this paper, that addresses the issue of the influence of the loading type on the resistance of the beam, achieving better agreement with the real behaviour while maintaining safety. (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 119 (0 ULg)
Full Text
Peer Reviewed
See detailLateralized processing of false memories and pseudoneglect in aging.
Schmitz, Rémy; Dehon, Hedwige ULg; Peigneux, Philippe ULg

in Cortex : A Journal Devoted to the Study of the Nervous System & Behavior (2012)

Aging is associated with higher propensity to false memories and decreased retrieval of previously studied items. When young adults perform on a lateralized version of the Deese-Roediger-McDermott (DRM ... [more ▼]

Aging is associated with higher propensity to false memories and decreased retrieval of previously studied items. When young adults perform on a lateralized version of the Deese-Roediger-McDermott (DRM) paradigm, the right cerebral hemisphere (RH) is more sensitive than the left (LH) to false memories, suggesting hemispheric imbalance in the cerebral mechanisms supporting semantic and episodic memory processes. Since cerebral asymmetries tend to be reduced with age, we surmised that behavioral asymmetries in the generation of false memories would be diminished with aging. To probe this hypothesis, a lateralized version of the DRM paradigm was administered to old (OA) and young (YA) healthy adults. During the encoding phase, lists of semantically associated words were memorized. During the retrieval session, targets (previously seen words), lures (never seen strongly semantically related words) and distracters (never seen, unrelated words) were briefly displayed either in the left or right visual fields, thus primarily stimulating the RH or LH, respectively. Participants had to decide whether the word was previously studied (Old/New), but also whether they had a strong episodic recollection (Remember) or a mere feeling of familiarity (Know) about Old words. In line with our predictions, false memories were globally higher in OA than YA, and vivid false recollections (i.e. Remember responses) were higher when lures were presented in the RH in YA, but not in OA. Additionally, we found significant correlations between YA participants’ familiarity scores and leftward attentional bias as previously evidenced using a visuospatial landmark task [Schmitz, R., and Peigneux, P. (2011). Age-related changes in visual pseudoneglect. Brain and Cognition, 76(3), 382-389], an effect not present in OA. This result is in line with the hypothesis of an interplay between attentional resources allocated to visuospatial and memory processes, suggesting a memory pseudoneglect phenomenon that would be altered with aging. [less ▲]

Detailed reference viewed: 47 (2 ULg)
Full Text
See detailLatest developments in palynology and palaeobotany
Steemans, Philippe ULg; Gerrienne, Philippe ULg

Book published by Paléogéobio. Paléobot. Paléopalyno. (2008)

Detailed reference viewed: 84 (18 ULg)
Full Text
See detailThe latest developments on Of?p stars
Nazé, Yaël ULg; ud-Doula, Asif; Spano, Maxime et al

in Neiner, Coralie; Wade, G.; Meynet, G. (Eds.) et al Active OB stars: structure, evolution, mass loss and critical limits (2011, July 01)

In recent years several in-depth investigations of the three prototypical Of?p stars were undertaken, revealing their peculiar properties. To clarify some of the remaining questions, we have continued our ... [more ▼]

In recent years several in-depth investigations of the three prototypical Of?p stars were undertaken, revealing their peculiar properties. To clarify some of the remaining questions, we have continued our monitoring of the prototypical Of?p trio. HD 108 has now reached its quiescent, minimum-emission state, for the first time in 50-60yrs, while new echelle spectra of HD 148937 confirm the presence in several H and He lines of the 7d variations detected previously only in the Hα line. A new XMM observation of HD 191612 clearly shows that its X-ray emission is not modulated by the orbital period of 1542d, but the high-energy variations are rather compatible with the 538d period of the optical changes - it is thus not of colliding-wind origin but linked to the phenomena responsible for the spectral/photometric variations, though our current MHD simulations remain at odds with the observational properties. [less ▲]

Detailed reference viewed: 17 (2 ULg)
Full Text
Peer Reviewed
See detailLatest Devonian and early Carboniferous palynostratigraphy of northern Brazil and north Africa - a proposed integration of Western European and Gondwanan miospore biozonations.
Loboziak, S; Melo, J.H.G.; Streel, Maurice ULg

in Bulletin du Centre de Recherches Elf Exploration Production (2000), 22(2), 241-259

Detailed reference viewed: 15 (1 ULg)
Peer Reviewed
See detailLatest Devonian to Early Carboniferous biostratigraphy of Northern Brazil: an update.
Melo, JHG; Loboziak, S; Streel, Maurice ULg

in Bulletin du Centre de Recherches Elf Exploration Production (1999), 22(1), 13-33

Detailed reference viewed: 17 (0 ULg)