Publications ORBi OA
Bookmark and Share    
Full Text
Peer Reviewed
See detailLe droit de partir, un droit oublié
Gemenne, François ULg

in Clochard, Olivier (Ed.) Atlas des Migrants en Europe (2009)

Detailed reference viewed: 26 (1 ULg)
Full Text
Peer Reviewed
See detailCompletely inelastic ball
Gilet, Tristan ULg; Vandewalle, Nicolas ULg; Dorbolo, Stéphane ULg

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2009)

Detailed reference viewed: 133 (27 ULg)
Full Text
Peer Reviewed
See detailAnalytical solutions for the thick-walled cylinder problem modeled with an isotropic elastic second gradient constitutive equation
Collin, Frédéric ULg; Caillerie, Denis; Chambon, René

in International Journal of Solids and Structures (2009), 46

Numerical modelling of localization phenomena shows that constitutive equations with internal length scale are necessary to properly model the post-localization behaviour. Moreover, these models allow an ... [more ▼]

Numerical modelling of localization phenomena shows that constitutive equations with internal length scale are necessary to properly model the post-localization behaviour. Moreover, these models allow an accurate description of the scale effects observed in some phenomena like micro indentation. This paper proposes some analytical results concerning a boundary value problem in a medium with microstructure. In addition to their own usefulness, such analytical solutions can be used in benchmark exercises for the validation of numerical codes. The paper focuses on the thick-walled cylinder problem, using a general small strain isotropic elastic second gradient model. The most general isotropic elastic model involving seven different constants is used and the expression of the analytical solutions is explicitly given. The influence of the microstructure is controlled by the internal length scale parameter. The classical macrostress is no more in equilibrium with the classical forces at the boundary. Double stresses are indeed also generated by the classical boundary conditions and, as far as the microstructure effects become predominant (i.e. the internal length scale is much larger than the thickness of the cylinder), the macrostresses become negligible. This leads to solutions completely different from classical elastic ones. [less ▲]

Detailed reference viewed: 226 (10 ULg)
Full Text
Peer Reviewed
See detailK-shell photoionization and photoabsorption of Ne, Mg, Si, S, Ar and Ca
Witthoeft, M; Bautista, M A; Mendoza, C et al

in Astrophysical Journal Supplement Series (2009), 182

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailPrincipes de modélisation pour la simulation acoustique
Dawans, Arnaud ULg; Demaret, Jean-Noël ULg; Safin, Stéphane ULg et al

in Bignon, Jean-Claude; Halin, Gilles; Kubicki, Sylvain (Eds.) Conception architecturale numérique et approches environnementales : Actes du 3ème séminaire de conception architecturale numérique (2009)

L'article présente la démarche de développement d’une méthode logicielle de modélisation architecturale, développée à l'intention des acousticiens chargés de formuler les options technologiques ... [more ▼]

L'article présente la démarche de développement d’une méthode logicielle de modélisation architecturale, développée à l'intention des acousticiens chargés de formuler les options technologiques nécessaires pour assurer les performances acoustiques d’un bâtiment (salle de concert, auditoire, théâtre, etc.). Basé sur une approche "centrée utilisateur", l'outil facilite grandement la description géométrique et technologique de l'espace intérieur en conception. Nous présentons d’abord l’analyse d’activité d’un acousticien qui nous a permis de poser les grandes options du modeleur. Nous décrivons ensuite les principes d’interaction qui sous-tendent l’application et nous illustrons ses atouts et parti-cularités par rapport aux méthodes actuelles. Finalement, nous commentons une première évaluation et nous discutons de la pertinence du développement d’outils de modélisation spécialisés. [less ▲]

Detailed reference viewed: 276 (41 ULg)
Full Text
Peer Reviewed
See detailSpécification géométrique des concepts architecturaux dans le cadre de la thermique du bâtiment
Juchmes, Roland ULg; Delfosse, Vincent ULg; Safin, Stéphane ULg et al

in Tidafi, T.; Dorta, T. (Eds.) Joindre langages, cultures & visions (2009)

Cette étude s’intéresse à l’assignation des propriétés technologiques des parois dans un modeleur architectural 3D. Nous proposons une méthode originale basée sur le principe de groupements sémantiques de ... [more ▼]

Cette étude s’intéresse à l’assignation des propriétés technologiques des parois dans un modeleur architectural 3D. Nous proposons une méthode originale basée sur le principe de groupements sémantiques de faces par requêtes géométriques. Nous décrivons la méthode et les résultats d’entretiens menés auprès d’architectes pour identifier les groupements pertinents, listons les requêtes géométriques simples pour la sélection de ces groupements et rendons compte de l’efficacité de la méthode sur un cas. Nous concluons sur les avantages et limites de l’approche. [less ▲]

Detailed reference viewed: 136 (11 ULg)
Full Text
Peer Reviewed
See detailRegional, Interregional and Global Arrangements and Organizations
Santander, Sébastian ULg

in Telò, Mario (Ed.) International Relations: A European Perspective (2009)

Cet contribution trace un large panorama des accords régionaux et interrégionaux et revient aussi sur les organismes multilatéraux

Detailed reference viewed: 26 (11 ULg)
Full Text
Peer Reviewed
See detailThe use of time use surveys to study activity participation: emerging issues
Cools, Mario ULg; Moons, Elke; Wets, Geert

Conference (2009)

Time use surveys often are carried out to identify, classify and quantify social behaviour of people by focusing on the activities that people perform. Time use data, in the transportation field often ... [more ▼]

Time use surveys often are carried out to identify, classify and quantify social behaviour of people by focusing on the activities that people perform. Time use data, in the transportation field often referred to as activity-based data, can be used to study a variety of sociological, economic, and technological phenomena. Studying behaviour, social networks and transport patterns are a few of the topics that can be analysed based on these time use data. This first introductory paper discusses some emerging issues in the collection of travel-related data such as automatic spatial information recording using cell phones and GPS, and survey design experiences. On the one hand new technology offers the opportunity to record at a relative low cost a wide variety of the data, while on the other hand new problems occur. One of such problems for instance is the problems of ‘cold starts’ faced with GPS devices, clouding the first minutes of recording after each restart of the device after it was turned off completely. Notwithstanding, applications of new technologies offer the opportunity for performing detailed space-time analyses in different fields ranging from epidemiology to transportation science. Some of these applications are highlighted in this session. Next to the advantages and potential risks of new technologies, this introductory paper also discusses the combination of different modes to analyze space-time behaviour. In particular, this study investigates potential mixed mode design effects, observed in a large activity-based travel survey, using a PDA application on the one hand, and traditional paper and pencil diaries on the other hand. The mixed-mode effects are analysed using heteroscedastic linear regression models, taking into account not only mode-effects, but also potential fatigue-effects. The results show that in this mixed-mode survey no attrition effects are present, and that the survey mode (PDA versus paper and pencil) has no direct impact on the quantities investigated (number of out-of-home activities reported and number of trips). [less ▲]

Detailed reference viewed: 13 (0 ULg)
Full Text
See detailÉtude de la modalité en néo-égyptien
Polis, Stéphane ULg

Doctoral thesis (2009)

Cette thèse constitue la première étude générale de la modalité en néo-égyptien. Le chapitre introductif (p. 5-43) est consacré [1] à la définition de ce premier état de langue de l’égyptien de la seconde ... [more ▼]

Cette thèse constitue la première étude générale de la modalité en néo-égyptien. Le chapitre introductif (p. 5-43) est consacré [1] à la définition de ce premier état de langue de l’égyptien de la seconde phase ; cette définition a permis la délimitation d’un corpus servant d’assise empirique à l’étude (la répartition du corpus en fonction de critères chronologiques et géographiques, de la nature du support et des "Textsorten" a donné la possibilité de pondérer et d’objectiver les analyses proposées pour chaque expression de la modalité). Ensuite, [2] un cadre théorique général pour l’étude de la langue est discuté. Le corps du travail se divise en trois parties consacrées respectivement : [1] à une définition générale de la notion de modalité (cela afin de déterminer les media expressifs qui relèvent de son étude en néo-égyptien) ainsi qu’à l’établissement d’un modèle sémantique à la fois économique, cohérent et correspondant aux données typologiques (p. 44-115) ; [2] à l’étude des modalités radicales (i.e. les modalités déontiques et bouliques en envisageant les relations qu’elles entretiennent avec le domaine axiologique ; p. 116-341) ; [3] à l’examen des modalités assertives (p. 342-446) : [a] analyse des formes de complémentation, en ce compris les liens entre intégration syntaxique, variation de l’assertivité et degré de manipulation, [b] étude de l’impact des auxiliaires d’énonciation sur le degré d’assertivité d’une proposition, [c] critique des théories existantes concernant les moyens expressifs du discours indirect en néo-égyptien. Les conclusions (p. 447-466) sont accompagnées de propositions prospectives devant permettre [1] de rendre le modèle défendu applicable à l’étude des complexes conditionnels, [2] d’intégrer la dimension énonciative dans l’analyse des relations interpersonnelles, [3] de proposer une approche globale des media expressifs de la causalité et de la finalité. [less ▲]

Detailed reference viewed: 339 (18 ULg)
Full Text
Peer Reviewed
See detailSpectrum synthesis modeling of the X-ray spectrum of GRO J1655-40 during the 2005 outburst
Kallman, T R; Bautista, M A; Goriely, S et al

in Astrophysical Journal (2009), 701

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailRadiative transition rates and collision strengths for Si II
Bautista, M A; Quinet, Pascal ULg; Palmeri, P et al

in Astronomy and Astrophysics (2009), 508

Detailed reference viewed: 1 (0 ULg)
Full Text
Peer Reviewed
See detailStructure of the archaeal pab87 peptidase reveals a novel self-compartmentalizing protease family.
Delfosse, Vanessa; Girard, Eric; Birck, Catherine et al

in PLoS ONE (2009), 4(3), 4712

Self-compartmentalizing proteases orchestrate protein turnover through an original architecture characterized by a central catalytic chamber. Here we report the first structure of an archaeal member of a ... [more ▼]

Self-compartmentalizing proteases orchestrate protein turnover through an original architecture characterized by a central catalytic chamber. Here we report the first structure of an archaeal member of a new self-compartmentalizing protease family forming a cubic-shaped octamer with D(4) symmetry and referred to as CubicO. We solved the structure of the Pyrococcus abyssi Pab87 protein at 2.2 A resolution using the anomalous signal of the high-phasing-power lanthanide derivative Lu-HPDO3A. A 20 A wide channel runs through this supramolecular assembly of 0.4 MDa, giving access to a 60 A wide central chamber holding the eight active sites. Surprisingly, activity assays revealed that Pab87 degrades specifically d-amino acid containing peptides, which have never been observed in archaea. Genomic context of the Pab87 gene showed that it is surrounded by genes involved in the amino acid/peptide transport or metabolism. We propose that CubicO proteases are involved in the processing of d-peptides from environmental origins. [less ▲]

Detailed reference viewed: 25 (8 ULg)
Full Text
Peer Reviewed
See detailCoal Suitability of the Measurement of Unburned Carbon by Laser-induced Breakdown Spectroscopy
Yao, Shunchun; Lu, Jidong; Pan, Shenghua et al

in Proceedings of the CSEE (2009), 29(3), 80-83

Laser-induced breakdown spectroscopy was used to analyze unburned carbon in fly ash. The samples were gotten using fast ashing method and excited by pulse laser and plasma was formed at atmospheric ... [more ▼]

Laser-induced breakdown spectroscopy was used to analyze unburned carbon in fly ash. The samples were gotten using fast ashing method and excited by pulse laser and plasma was formed at atmospheric pressure. The emitted signal which contains the information of unburned carbon in fly ash was detected. The calibration curve constructed base on six samples of one kind of coal ash, and two samples of other two kinds of coal ash were analyzed. The experimental results show that calibration curve constructed with the data from same kind of coal ash can be used to analyze the different kinds of fly ash using proper data processing method. The relative standard deviation of repetition of measured values are less than 8.08%, the relative errors are less than 2.27%. It is indicated that laser-induced breakdown spectroscopy is suitable for rapidly detect unburned carbon in fly ash with receptible applicability. [less ▲]

Detailed reference viewed: 27 (0 ULg)
Full Text
Peer Reviewed
See detailLaser-induced breakdown spectroscopy for analysis of soil elements
Lin, Zhaoxiang; Li, Jie ULg; Liu, Linmei et al

in High Power Laser and Particle Beams (2009), 21(6), 817820

A laser—induced breakdown spectroscopy(LIBS)set—up has been established,and a series of experiments have been carried out with soil samples.The calibration curves of the lines intensities versus the mass ... [more ▼]

A laser—induced breakdown spectroscopy(LIBS)set—up has been established,and a series of experiments have been carried out with soil samples.The calibration curves of the lines intensities versus the mass fraction of the elements were acquired by the experiment.Eighteen elements including Mg,Ca and Na were found in the sample of the soil around the South—Central University for Nationalities by qualitative analysis.Only three elements,Fe,Mg and Ca,were found in the rock at Zhuyufeng peak.These results indicate that the physical composition of soil sample impact on the precision of LIBS. [less ▲]

Detailed reference viewed: 30 (3 ULg)
Full Text
Peer Reviewed
See detailExperimental investigation on plasma temperature of Ca by laser—induced breakdown spectroscopy
Li, Jie ULg; Lu, Jidong; Lin, Zhaoxiang et al

in High Power Laser and Particle Beams (2009), 21(5), 689-693

The )lasma temperature is an important factor in quantitative analysis by laser induced breakdown spectroscopy(LIBS).The plasmas were generated by a Nd:YAG laser 0n the surface of sample and detected by ... [more ▼]

The )lasma temperature is an important factor in quantitative analysis by laser induced breakdown spectroscopy(LIBS).The plasmas were generated by a Nd:YAG laser 0n the surface of sample and detected by an Echelle spectrograph and an Intensified Charge—Couplea Device(ICCD).The spectrum of 300 nm to 450 nm recorded several spectral lines of Ca component such as Ca II 31 5.9 nm.Ca II 317.9 nrn.Ca 1I 393.4 nm,Ca Ⅱ 396.9 nm,Ca I 422.7 nm and so on.It is known that the change of plasma temperature has influence on the line intensity from the equation for quantitative LIBS analysis.It was assumed that the plasm as produced in the experiment were in local thermodynamic equilibrium(LTE).The temperature variations were deduced bv tine four 0ne—ionized Ca spectral lines and the Boltzmann plot,and the relationship between the plasma temperature and the concentration was obtained too.The plasma temperature increased when the concentration increased.When the mass fraction of Ca was lower than 0.50, the increase velocity of the plasma temperature was small. When the mass fraction of Ca was higher than 0.50, the increase was large.The hypothesis of local thermal equilibrium conditions of the plasma was confirmed in this experiment. [less ▲]

Detailed reference viewed: 40 (0 ULg)
Full Text
Peer Reviewed
See detailApplication of multiple-point geostatistics on modelling groundwater flow and transport in a cross-bedded aquifer
Huysmans, Marijke; Dassargues, Alain ULg

in Hydrogeology Journal (2009), 17(8), 1901-1911

Sedimentological processes often result in complex three-dimensional subsurface heterogeneity of hydrogeological parameter values. Variogram-based stochastic approaches are often not able to describe ... [more ▼]

Sedimentological processes often result in complex three-dimensional subsurface heterogeneity of hydrogeological parameter values. Variogram-based stochastic approaches are often not able to describe heterogeneity in such complex geological environments. This work shows how multiple-point geostatistics can be applied in a realistic hydrogeological application to determine the impact of complex geological heterogeneity on groundwater flow and transport. The approach is applied to a real aquifer in Belgium that exhibits a complex sedimentary heterogeneity and anisotropy. A training image is constructed based on geological and hydrogeological field data. Multiple-point statistics are borrowed from thistraining image to simulate hydrofacies occurrence, while intrafacies permeability variability is simulated using conventional variogram-based geostatistical methods. The simulated hydraulic conductivity realizations are used as input to a groundwater flow and transport model to investigate the effect of small-scale sedimentary heterogeneity on contaminant plume migration. Results show that small-scale sedimentary heterogeneity has a significant effect on contaminant transport in the studied aquifer. The uncertainty on the spatial facies distribution and intrafacies hydraulic conductivity distribution results in a significant uncertainty on the calculated concentration distribution. Comparison with standard variogram-based techniques shows that multiple-point geostatistics allow better reproduction of irregularly shaped low-permeability clay drapes that influence solute transport. [less ▲]

Detailed reference viewed: 91 (16 ULg)
Full Text
Peer Reviewed
See detailDetermination of As in Industrial Wastewater by Laser-Induced Breakdown Spectroscopy
Lin, Zhaoxiang; Chang, Liang; Li, Jie ULg et al

in Spectroscopy and Spectral Analysis (2009), 29(6), 1675-1677

The wastewater from industrial smelting process contains heavy metals such as arsenic(As)that produce serious environmental pollution and cause actual harm to the health of people. It is necessary to ... [more ▼]

The wastewater from industrial smelting process contains heavy metals such as arsenic(As)that produce serious environmental pollution and cause actual harm to the health of people. It is necessary to control the pollution at the source and achieve a real-time and online monitoring.The 1aser-induced breakdown spectroscopy(LIBS)iS a new elemental analysis technique,and has the advantage of rapid detection.An LIBs setup has been established.The Nd:YAG Iaser beam is focused onto the sample,then the plasmas are produced.The emission spectra of plasmas are dispersed by an Echelle spectrograph and detected by an intensified charge-coupled device(ICCD).Experiments have been carried out on the industrial wastewarer collected from the scene.The spectral lines of As element were obtained.The calibration curve of the line intensities versus the concentrations of the As element was acquired by the experiment.The calibration curve can be used for the quantitative analysis of arsenic element with an unknown concentration in the industrial wastewater.The results showed that the LIBS technique can be applied in the rapid detection of As element in industrial wastewater,and has wide range of applications [less ▲]

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
See detailExperimental Investigation on Quantitative Analysis of Glass by Laser Induced Breakdown Spectroscopy
Li, Pengyan; Xie, Chengli; Lu, Jidong et al

in Applied Laser (2009), 29(1), 21-25

Experimental investigation of quantitative analysis of glass by calibration-free laser induced breakdown spectroscopy (CF LIBS)was carried out in this paper.An intense laser radiation with a wavelength of ... [more ▼]

Experimental investigation of quantitative analysis of glass by calibration-free laser induced breakdown spectroscopy (CF LIBS)was carried out in this paper.An intense laser radiation with a wavelength of 1064nm was used to ablate fine glass to form plasma plume, and the emission spectrum emitted as the plasma cooling off was analyzed by high resolution echelle grating spectrometer coupled to Intensified Charge Coupled Device(ICCD)cam era.The results show that the intensity and repeatability of spectrum is best on the condition of laser pulse focused above the surface of sample,and in this experiment the height is about 3 mm. By the CF-I IBS,the relative errors of quantitative analysis of elem ents in glass varied between 3.6% ~11.2 %,and good repeatability with relative standard deviation between 1.6% ~ 7.7% for five measurements was obtained. [less ▲]

Detailed reference viewed: 38 (0 ULg)
Full Text
Peer Reviewed
See detailCorrection and analysis of lead content in soil by laser-induced breakdown spectroscopy
Xie, Chengli; Lu, Jidong; Li, Pengyan et al

in Chinese Optics Letters (2009), 7(6), 545548

Detailed reference viewed: 20 (0 ULg)