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See detailMeasuring the phase of the scattering amplitude with vortex beams
Ivanov, Igor ULg

in Physical Review. D : Particles and Fields (2012), 85(7), 07600110

We show that colliding vortex beams instead of (approximate) plane waves can lead to a direct measurement of how the overall phase of the plane wave scattering amplitude changes with the scattering angle ... [more ▼]

We show that colliding vortex beams instead of (approximate) plane waves can lead to a direct measurement of how the overall phase of the plane wave scattering amplitude changes with the scattering angle. Since vortex beams are coherent superpositions of plane waves with different momenta, their scattering amplitude receives contributions from plane wave amplitudes with distinct kinematics. These contributions interfere, leading to the measurement of their phase difference. Although interference exists for any generic wave packet collision, we show that using vortex beams dramatically enhances sensitivity to the phase in comparison with nonvortex beams. Since the overall phase is inaccessible in a plane wave collision, this measurement would be of great importance for a number of topics in hadronic physics, for example, meson production in the resonance region, physics of nucleon resonances, and small angle elastic hadron scattering. [less ▲]

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See detailMeasuring the Social Economy in the Framework of the National Accounts
Mertens de Wilmars, Sybille ULg

in Defourny, Jacques; Nyssens, Marthe; Develtere, Patrick (Eds.) et al The worldwide making of the social economy. Innovations and changes (2009)

Sybille Mertens examines a new major development in the recognition of the social economy (nonprofit organisations, cooperatives, mutuals, social enterprises. She describes the efforts of numerous ... [more ▼]

Sybille Mertens examines a new major development in the recognition of the social economy (nonprofit organisations, cooperatives, mutuals, social enterprises. She describes the efforts of numerous research teams around the world to improve the statistical knowledge and economic measurement of this sector, with aspecific focus on the development of satellite accounts. [less ▲]

Detailed reference viewed: 125 (8 ULg)
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See detailMeasuring the Technical Efficiency of Airports in Latin America
Perelman, Sergio ULg; Serebrisky, Tomas

in Utilities Policy (2012), 22

Detailed reference viewed: 33 (3 ULg)
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See detailMeasuring the thermophysical properties of materials at high temperature - Application to the additive manufacturing of alloy Ti-6Al-4V and of stainless steel 316L
Mertens, Anne ULg; Paydas, Hakan ULg; Reginster, Sylvie ULg et al

Conference (2013, November 07)

In view of optimising the microstructures of metallic materials and obtaining the desired properties, the accurate characterisation of the thermophysical behaviour of these materials has long been ... [more ▼]

In view of optimising the microstructures of metallic materials and obtaining the desired properties, the accurate characterisation of the thermophysical behaviour of these materials has long been considered of paramount importance e.g. by allowing for the in-situ study of phase transformations, by providing data for numerical simulations and, essentially, by contributing to a better understanding of the fundamental mechanisms at play during processing. In the present work, the thermophysical behaviour of Ti-alloy Ti-6Al-4V and of stainless steel 316L has been characterised in details, in order to reach a better understanding of the phenomena controlling the microstructures and mechanical properties of parts made by additive manufacturing techniques that appear nowadays very promising in view of the economic production of near-net-shape, complex and (almost) fully dense parts from metallic materials. In particular, the thermal conductivity of Ti-alloy Ti-6Al-4V and of stainless steel 316L at high temperature has been determined by combining dilatometry, Differential Scanning Calorimetry (DSC) and laser flash diffusivimetry based on Laplace’s equation : k(T)=α(T)ρ(T)Cp(T) where k(T) is the thermal conductivity (W/m*K) α(T) is the thermal diffusivity (mm2/s) ρ(T) is the specific mass (g/cm3) Cp(T) is the specific heat capacity (J/g*K). Since Ti-alloy Ti-6Al-4V and stainless steel 316L exhibit quite different physical behaviours, their careful comparison is shown to shed more light into the role of phenomena such as epitaxial growth, out-of-equilibrium phase transformations and/or internal stresses in the additive manufacturing of metallic materials. [less ▲]

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See detailMeasuring the Usability and Effectiveness of CAAD Tools and Applications
Attia, Shady ULg; Andersen, Marilyne

in Proceeding of the Education and research in Computer Aided Architectural Design in Europe Conference (2013, September)

Computer Aided Architectural Design (CAAD) decisions and judgments have been at the heart of architectural design practice. Despite the increasing popularity of computer aided design applications ... [more ▼]

Computer Aided Architectural Design (CAAD) decisions and judgments have been at the heart of architectural design practice. Despite the increasing popularity of computer aided design applications, measuring the decision making of designers empirically remains elusive. Past research claiming usefulness of the CAD has relied largely on anecdotal or case studies that are vulnerable to bias. The study reviews results of prior investigations. The relatively few laboratory experiments report hardly any empirical results regarding the measurement of CAD decision making. The study provides an overview of the literature of existing measurement methods that have been used in psychology and neuroscience to assess individual variations in design making, and highlight these different measurement methods’ strengths and weaknesses. We conclude with a comparative evaluation of the different measures and provide suggestions regarding their constructive use in building realistic theories of designer’s decision making measurement. [less ▲]

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See detailMeasuring Time Delays in Gravitational Lenses
Eulaers, Eva ULg; Magain, Pierre ULg; Sohy, Sandrine ULg et al

Poster (2008, September)

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See detailMeasuring Time Delays in Gravitational Lenses
Eulaers, Eva ULg

Master of advanced studies dissertation (2008)

Detailed reference viewed: 9 (0 ULg)
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See detailMeasuring Total Electron Content with GNSS: Investigation of Two Different Techniques
Bidaine, Benoît ULg; Warnant, René ULg

in The Institution of Engineering and Technology 11th International Conference on Ionospheric Radio Systems and Techniques (IRST 2009) (2009, April)

The ionosphere widely affects Global Navigation Satellite Systems (GNSS) applications, inducing among others a delay in GNSS measurements. This delay is closely linked to the Total Electron Content (TEC ... [more ▼]

The ionosphere widely affects Global Navigation Satellite Systems (GNSS) applications, inducing among others a delay in GNSS measurements. This delay is closely linked to the Total Electron Content (TEC) of the ionosphere, a major parameter which can hence be monitored using GNSS. To this extent, phase measurements are taken as a basis for their lower noise level. Levelling strategies have then to be defined for the phase measurements are obtained with an initial unknown number of cycles called ambiguity. The most common technique, referred to as carrier-to-code levelling, consists in using the differences between code and phase measurements and their average on a continuous set of epochs. This option, chosen at the Royal Meteorological Institute (RMI) of Belgium to compute TEC for Belgian GPS stations, requires code hardware delays estimation. Another has been proposed which takes benefit from Global Ionospheric Maps (GIMs) to compute a reference TEC used for ambiguity resolution. In order to understand the consequences of using one method or the other, we compare slant TEC data obtained from both techniques for a mid-latitude station (Brussels) during a high solar activity period (2002). We observed large differences (6.8 TECu on average) showing features apparently related to ionospheric and geomagnetic activity. We attribute these observations to a combination of effects originating in code delays estimation, multipath and noise as well as GIMs errors. We try to differentiate between these effects by focusing on several days and satellites. We concentrate for example on days presenting large TEC differences and geomagnetic disturbances simultaneously (or not) or on satellites displaying recurrent patterns on consecutive days. Finally we highlight the impact of the choice of GIMs involved in sTEC calibration. To this extent, we analyse vertical TEC statistics showing a general underestimation from RMI data. The highest bias (5.8 TECu) is obtained for the UPC GIMs used in the second levelling technique. [less ▲]

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See detailMEASURING VARIABILITY SOURCES IN NMR METABOLOMIC STUDIES
Rozet, Eric ULg; De Tullio, Pascal ULg; Hubert, Philippe ULg et al

Conference (2013, May 13)

Due to the huge amount of information available in NMR spectra obtained from the analysis of metabolomic experiments, multivariate analysis such as Principal Component Analysis (PCA) are required to ... [more ▼]

Due to the huge amount of information available in NMR spectra obtained from the analysis of metabolomic experiments, multivariate analysis such as Principal Component Analysis (PCA) are required to understand the influence of treatments over the metabolites [1]. However, many experiments in metabolomics studies have more complexes variability structures than simply comparing several treatments: they may include time effects, biological effects such as diet or hormonal status, and other blocking factors or variability sources: samples stability, age of the individuals, pH of a buffer, days of acquisition, and so on. Metabolomic data analysis needs to extract from the spectral data matrix the variations linked to a change indicated in the factor of interest. However other sources of variability may impair this objective. This stresses the importance to discover the sources of variability of the spectral metabolomic data using appropriate methodology. Classically, to analyze such data analysis of variance (ANOVA) or multivariate ANOVA (MANOVA) [2] is used. However direct application of these methodologies to NMR spectra obtained from structured metabolomics studies is inappropriate or impossible. More complex data analyses methodologies are required to understand the importance of the various factors implied in the experiments and to provide a measure of their variance components. Three related methodologies have been proposed to achieve this: ASCA [3], ANOVA-PCA [4] and AComDim [5]. The ASCA and ANOVA-PCA methodologies combine first an analysis of variance step (ANOVA) and then a PCA step. The AComDim one adds to the output of the ANOVA-PCA step a multi-block analysis. In this presentation, the usefulness and applicability of these advanced techniques to data analysis of NMR metabolomic spectra are provided to highlight the increase of knowledge gained and the estimation of main sources of variability arising in an experimental setup. Two NMR databases will be used [6]. The first one concerns human serum analyzed by 1H-NMR where three random factors are present: day of measurement (3 days), sample (2 samples per individual) and replication of analyses as well as two fixed controlled factors, time of measurement after thawing (2 times) and two protein suppression methods for the spectral pre-treatment. The second database is about the 1H-NMR analyses of rats’ urine where two different concentrations of citrate and of hippurate were deliberately added and three other sources of variability are present: urine pool diluted or not diluted, repetitions of analyses, days of analyses (three days), as well as two different spectral pre-treatment procedures. [less ▲]

Detailed reference viewed: 41 (6 ULg)
See detailMeat quality in relation to breed (Belgian blue vs Holstein) and conformation (double muscled vs dual purpose type)
Clinquart, Antoine ULg; Van Eenaeme, Christian ULg; Van Vooren, Tom et al

in Proceedings of the International Workshop on Proteolysis and Meat Quality (1993)

Detailed reference viewed: 19 (1 ULg)
Peer Reviewed
See detailLa mecanica respiratoria en terneros sanos respirando Helio-Oxigeno
Rodriguez, MN; Art, Tatiana ULg; Rollin, Frédéric ULg et al

in Proceedings of the XVIIIth Jordanas Uruguayas de Buiatria (1990)

Detailed reference viewed: 7 (0 ULg)
See detailMécanique analytique (1ère partie)
Dauby, Pierre ULg

Learning material (2010)

Detailed reference viewed: 99 (9 ULg)
See detailMécanique analytique (2ème partie)
Dauby, Pierre ULg

Learning material (2000)

Detailed reference viewed: 28 (2 ULg)
See detailMécanique des fluides
Dauby, Pierre ULg

Learning material (2007)

Detailed reference viewed: 48 (15 ULg)
See detailMécanique des milieux continus
Dauby, Pierre ULg

Learning material (2007)

Detailed reference viewed: 41 (8 ULg)
See detailLa mécanique du détail. Approches transversales
Hagelstein, Maud ULg; Belloi, Livio ULg

Book published by Editions de l'Ecole Normale Supérieure de Lyon (2014)

Parce qu’elle a trait aux relations nouées entre les parties et l’ensemble qui les comprend, la question du détail s’investit d’enjeux considérables pour toute tentative de réflexion interdisciplinaire ... [more ▼]

Parce qu’elle a trait aux relations nouées entre les parties et l’ensemble qui les comprend, la question du détail s’investit d’enjeux considérables pour toute tentative de réflexion interdisciplinaire. En effet, dans les disciplines qui s’attachent à rendre un objet visible ou lisible, les théoriciens rencontrent à l’endroit du détail des problèmes voisins, sinon analogues, que nous voudrions ici aborder de front, dans une perspective forcément « rapprochée » et plus que jamais attentive à des objets singuliers, que ceux-ci relèvent de la littérature, du cinéma, de la photographie, de la bande dessinée, de la peinture, de la philosophie, etc. À confronter nos méthodes et les présupposés sur lesquels elles reposent, il nous a semblé possible de cerner plus finement le mode de fonctionnement propre au détail. Certes, chacun fera part ici de ses étonnements particuliers ; de même, chacun sera amené à faire rapport des découvertes enthousiasmantes ou perturbantes qui, dans son domaine spécifique, auront innervé le travail de réflexion. Pourtant, il aurait été inutile de vouloir dresser une simple liste de détails, recueillis au sein d’une compilation bariolée et forcément non exhaustive. Adoptant une perspective plus large, le présent ouvrage vise à une compréhension approfondie de la mécanique du détail (extrait de l'Avant-propos, L. Belloï & M. Hagelstein). [less ▲]

Detailed reference viewed: 67 (3 ULg)