Last 7 days
Bookmark and Share    
Full Text
See detailComputational modeling of concrete structures in fire - Capabilities, frontiers, and opportunities
Gernay, Thomas ULiege

Scientific conference (2017, October 03)

Detailed reference viewed: 21 (1 ULiège)
See detailMontages structuralistes dans Les Temps Modernes
Cormann, Grégory ULiege

Scientific conference (2017, October 02)

Detailed reference viewed: 19 (1 ULiège)
Full Text
See detailNotebooks for documenting work-flows
Troupin, Charles ULiege; Barth, Alexander ULiege; Muñoz, Cristian et al

Conference (2017, October 02)

Detailed reference viewed: 13 (1 ULiège)
Full Text
Peer Reviewed
See detailProbing dark matter substructure in the gravitational lens HE 0435‑1223 with the WFC3 grism
Nierenberg, A. M.; Treu, T.; Brammer, G. et al

in Monthly Notices of the Royal Astronomical Society (2017), 471

Strong gravitational lensing provides a powerful test of Cold Dark Matter (CDM) as it enables the detection and mass measurement of low mass haloes even if they do not contain baryons. Compact lensed ... [more ▼]

Strong gravitational lensing provides a powerful test of Cold Dark Matter (CDM) as it enables the detection and mass measurement of low mass haloes even if they do not contain baryons. Compact lensed sources such as Active Galactic Nuclei (AGN) are particularly sensitive to perturbing subhalos, but their use as a test of CDM has been limited by the small number of systems which have significant radio emission which is extended enough avoid significant lensing by stars in the plane of the lens galaxy, and red enough to be minimally affected by differential dust extinction. Narrow-line emission is a promising alternative as it is also extended and, unlike radio, detectable in virtually all optically selected AGN lenses. We present first results from a WFC3 grism narrow-line survey of lensed quasars, for the quadruply lensed AGN HE0435-1223. Using a forward modelling pipeline which enables us to robustly account for spatial blending, we measure the [OIII] 5007 \AA~ flux ratios of the four images. We find that the [OIII] fluxes and positions are well fit by a simple smooth mass model for the main lens. Our data rule out a $M_{600}>10^{8} (10^{7.2}) M_\odot$ NFW perturber projected within $\sim$1\farcs0 (0\farcs1) arcseconds of each of the lensed images, where $M_{600}$ is the perturber mass within its central 600 pc. The non-detection is broadly consistent with the expectations of $\Lambda$CDM for a single system. The sensitivity achieved demonstrates that powerful limits on the nature of dark matter can be obtained with the analysis of $\sim20$ narrow-line lenses. [less ▲]

Detailed reference viewed: 14 (3 ULiège)
Full Text
See detailBayesian Multi-Objective Optimisation of Neotissue Growth in a Perfusion Bioreactor Set-up
olofsson, Simon; Mehrian, Mohammad ULiege; Geris, Liesbet ULiege et al

Scientific conference (2017, October 01)

We consider optimising bone neotissue growth in a 3D scaffold during dynamic perfusion bioreactor culture. The goal is to choose design variables by optimising two conflicting objectives: (i) maximising ... [more ▼]

We consider optimising bone neotissue growth in a 3D scaffold during dynamic perfusion bioreactor culture. The goal is to choose design variables by optimising two conflicting objectives: (i) maximising neotissue growth and (ii) minimising operating cost. Our contribution is a novel extension of Bayesian multi-objective optimisation to the case of one black-box (neotissue growth) and one analytical (operating cost) objective function, that helps determine, within a reasonable amount of time, what design variables best manage the trade-off between neotissue growth and operating cost. Our method is tested against and outperforms the most common approach in literature, genetic algorithms, and shows its important real-world applicability to problems that combine black-box models with easy-to-quantify objectives like cost. [less ▲]

Detailed reference viewed: 38 (3 ULiège)
Full Text
Peer Reviewed
See detailH0LiCOW - II. Spectroscopic survey and galaxy-group identification of the strong gravitational lens system HE 0435-1223
Sluse, Dominique ULiege; Sonnenfeld, A.; Rumbaugh, N. et al

in Monthly Notices of the Royal Astronomical Society (2017), 470

Galaxies located in the environment or along the line of sight towards gravitational lenses can significantly affect lensing observables, and can lead to systematic errors on the measurement of H[SUB]0 ... [more ▼]

Galaxies located in the environment or along the line of sight towards gravitational lenses can significantly affect lensing observables, and can lead to systematic errors on the measurement of H[SUB]0[/SUB] from the time-delay technique. We present the results of a systematic spectroscopic identification of the galaxies in the field of view of the lensed quasar HE 0435-1223 using the W. M. Keck, Gemini and ESO-Very Large telescopes. Our new catalogue triples the number of known galaxy redshifts in the direct vicinity of the lens, expanding to 102 the number of measured redshifts for galaxies separated by less than 3 arcmin from the lens. We complement our catalogue with literature data to gather redshifts up to 15 arcmin from the lens, and search for galaxy groups or clusters projected towards HE 0435-1223. We confirm that the lens is a member of a small group that includes at least 12 galaxies, and find 8 other group candidates near the line of sight of the lens. The flexion shift, namely the shift of lensed images produced by high-order perturbation of the lens potential, is calculated for each galaxy/group and used to identify which objects produce the largest perturbation of the lens potential. This analysis demonstrates that (i) at most three of the five brightest galaxies projected within 12 arcsec of the lens need to be explicitly used in the lens models, and (ii) the groups can be treated in the lens model as an external tidal field (shear) contribution. [less ▲]

Detailed reference viewed: 27 (2 ULiège)
Full Text
See detailIsotopic Ratios in a Peculiar Outbursting Comet
Yang, Bin; Hutsemekers, Damien ULiege; Shinnaka, Yoshiharu et al

in Bulletin of the American Astronomical Society (2017, October 01), 49

Isotopic ratios in comets provide keys for the understanding of the origin of cometary material, and the physical and chemical conditions in the early Solar Nebula. A newly discovered peculiar comet, C ... [more ▼]

Isotopic ratios in comets provide keys for the understanding of the origin of cometary material, and the physical and chemical conditions in the early Solar Nebula. A newly discovered peculiar comet, C/2015 ER61, underwent an outburst with a total brightness increase of 2 magnitudes on the night of April 4th, 2017. The sharp increase in brightness offers a rare opportunity to measure the isotopic ratios of the light elements of this comet. We obtained two high-resolution spectra of C/2015 ER61 with UVES on Apr. 13 and Apr. 17 respectively. At the time of our observations, the comet was fading gradually since the outburst. We measured the 12C/13C and 14N/15N isotopic ratios from the CN Violet (0,0) band. In addition, we determined the 14N/15N ratio in NH2 for C/2015 ER61 from four pairs of NH2 isotopologue lines. Some 18OH lines were detected but the S/N of these lines is too low to derive a reliable 18O/16O estimate. We will present our UVES spectra of C/2015 ER61, obtained shortly after the outburst. We will also present the comparison of the Isotopic ratios of C/2015 ER61 with those of other comets. [less ▲]

Detailed reference viewed: 11 (1 ULiège)
Full Text
Peer Reviewed
See detailSurveillance de l'atmosphère terrestre depuis la station du Jungfraujoch : une épopée liégeoise entamée voici plus de 65 ans !
Mahieu, Emmanuel ULiege; Bader, Whitney ULiege; Bovy, Benoît ULiege et al

in Bulletin de la Société Géographique de Liège (2017), 68

It’s in the early 1950s that researchers from the University of Liège started to investigate the Earth’s atmosphere from the Jungfraujoch scientific station, in the Swiss Alps, at a time when concerns ... [more ▼]

It’s in the early 1950s that researchers from the University of Liège started to investigate the Earth’s atmosphere from the Jungfraujoch scientific station, in the Swiss Alps, at a time when concerns related to atmospheric composition changes were nonexistent. Since then, an infrared observational data base unique worldwide has been carefully collected. The exploitation of these observations has allowed constituting multi-decadal time series crucial for the characterization of the changes that affected our atmosphere and for the identification of their causes. In this paper, we first remind about the successive steps which led to establishing the observational program of the Liège team at the Jungfraujoch and we evoke important findings which justified its continuation. Then we present some recent results relevant to the Montreal and Kyoto Protocols, or related to the monitoring of air quality. [less ▲]

Detailed reference viewed: 21 (2 ULiège)
See detailVive les hauts-fourneaux! Vers une reconnaissance du patrimoine sidérurgique en Wallonie
Drouguet, Noémie ULiege; Bodeux, Philippe

Book published by Urbagora (2017)

Marcinelle, Ougrée, Clabecq. Trois hauts-lieux de production de fonte et d'acier, dominés par la figure emblématique des hauts-founeaux. A l'arrêt depuis plusieurs années, devenus des friches, ils sont ... [more ▼]

Marcinelle, Ougrée, Clabecq. Trois hauts-lieux de production de fonte et d'acier, dominés par la figure emblématique des hauts-founeaux. A l'arrêt depuis plusieurs années, devenus des friches, ils sont appelés à disparaître prochainement. Avant qu’ArcelorMittal et Duferco ne rasent ces vestiges, les questions de régénération des sites et de préservation du patrimoine sont à étudier conjointement. Fermées, grillagées et laissées à l’abandon, ces forêts industrielles doivent s’ouvrir à ceux qui ont des propositions à défendre, qu'ils soient urbanistes, architectes, promoteurs, artistes, passeurs de mémoire. Les bassins voisins –la Ruhr, la Sarre ou la Lorraine – ont chacun gardé des témoins de l’épopée industrielle pour les recycler en parcs paysagers, musées, ville nouvelle ou espaces économiques. Point de départ de la révolution industrielle sur le continent, la Wallonie ne peut faire l’impasse sur une réflexion approfondie concernant le devenir des friches sidérurgiques. Ce numéro hors-série de Dérivation pose la question et tente de documenter le débat, plus complexe qu'il n'y paraît. Il entend à la fois plonger dans une réalité où se mêlent ville et industrie, en décrire ce qui échappe aux regards, mais aussi donner la parole à ceux qui l’ont côtoyée de près et amener quelques propositions. [less ▲]

Detailed reference viewed: 20 (2 ULiège)
See detailUnderwater world: the end of the myth
Parmentier, Eric ULiege

Conference (2017, October)

Detailed reference viewed: 14 (1 ULiège)
Full Text
Peer Reviewed
See detailRecent Evolutions and Trends in the Use of Computer Aided Chemical Engineering for Educational Purposes at the University of Liège
Léonard, Grégoire ULiege; Belboom, Sandra ULiege; Toye, Dominique ULiege et al

in Computer Aided Chemical Engineering (2017)

The present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies ... [more ▼]

The present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies with the arrival of commercial software is highlighted, as the learning outcomes evolved from the ability of building programs to solve chemical engineering problems towards the ability to use complex commercial software and to understand their limitations. Moreover, CAPE methods were extended to non-dedicated CAPE courses, which is illustrated here by the goals and challenges of their use in courses like “Reactor Engineering” and “Life Cycle Analysis”. It was observed that students sometimes assume that CAPE softwares provide straightforward and trustworthy solutions without the need of understanding their mathematical bases and assumptions. Thus, solutions to make students aware of these limitations are proposed, including the creation of an integrated project focussing on complex multi-disciplinary issues, evidencing the need for critical input from the operator. [less ▲]

Detailed reference viewed: 29 (6 ULiège)
Full Text
Peer Reviewed
See detailPond drying cues and their effects on growth and metamorphosis in a fast developing amphibian
Székely, Diana ULiege; Denoël, Mathieu ULiege; Székely, Paul et al

in Journal of Zoology (2017), 303(2), 129-135

The hydroperiod of breeding habitats imposes a strong selection on amphibians and pond-breeding species usually exhibit a high degree of plasticity in the duration of larval period. However, the potential ... [more ▼]

The hydroperiod of breeding habitats imposes a strong selection on amphibians and pond-breeding species usually exhibit a high degree of plasticity in the duration of larval period. However, the potential for phenotypic plasticity in fast developing species was investigated only in a small number of anurans, and the specific response to environmental cues such as low water versus decreasing water level, as well as the effects of such cues on particular developmental stages, are even less understood. In this context, we investigated the plastic response to pond desiccation in a neotropical species (Ceratophrys stolzmanni) by raising tadpoles in three water level treatments: constant high, constant low and decreasing. The growth rates were the highest reported for amphibian tadpoles (up to 0.3g/day) and the time to metamorphosis was short in all treatments, with the fastest developing tadpole metamorphosing in only 16 days after egg deposition. Individuals from the constant high water level treatment had a higher growth rate than those in the other two treatments, whereas decreasing and constant low water levels had similar effects on development, speeding up metamorphosis. In turn, this involved a cost as these tadpoles had a lower body size and mass at metamorphosis than the ones raised in constant high water levels. The final stages of metamorphosis, when tadpoles are the most vulnerable, were shorter in tadpoles exposed to a decreasing water level, allowing them to leave water quickly. Our experiment demonstrates that phenotypic plasticity is maintained even in environments devoid of permanent aquatic habitats. Ceratophryd tadpoles are able to shorten their developmental time when they perceive a risk of desiccation and react similarly to cues coming from the two unfavorable water conditions showing their adaptation to ephemeral and unpredictable breeding habitats. [less ▲]

Detailed reference viewed: 48 (10 ULiège)
Full Text
Peer Reviewed
See detailThe Paleoproterozoic fossil record: Implications for the evolution of the biosphere during Earth's middle-age
Javaux, Emmanuelle ULiege; lepot, kevin

in Earth-Science Reviews (2017)

Detailed reference viewed: 19 (1 ULiège)
Full Text
Peer Reviewed
See detailOn the phase behaviour of oxetane-CO2 and propargylic alcohols-CO2 binary mixtures by in situ infrared micro-spectrometry
Zaky, Mohamed; Boyaval, Amélie ULiege; Grignard, Bruno ULiege et al

in Journal of Supercritical Fluids (2017), 128

The phase behaviour of carbon dioxide/propargylic alcohols and carbon dioxide/oxetanes mixtures has been investigated using in-situ FTIR microspectrometry that allows us determining the evolution of the ... [more ▼]

The phase behaviour of carbon dioxide/propargylic alcohols and carbon dioxide/oxetanes mixtures has been investigated using in-situ FTIR microspectrometry that allows us determining the evolution of the concentration of each component in the liquid phase as a function of temperature and pressure. It was at the same time possible to look inside the cell and to visualize the expansion of the liquid phase during the increase of the pressure. The measurements were performed at three different temperatures (40, 70 and 100◦C) for pressures ranging between 0.1 and 15 MPa. Propargylic alcohol (PA), 2-methyl-3-butyn-2-ol (MBOL), 3-butyn-1-ol (BOL) and trimethylene oxide (TMO) were selected as these molecules are used in the synthesis of cyclic or polycarbonates by coupling with CO2. Thus, we determined the CO2 sorption and the concentration of the substrate in the liquid phase. Thanks to these measurements, we established the pressure-composition phase diagram for the liquid phase of these substrate/CO2 binary mixtures. [less ▲]

Detailed reference viewed: 45 (15 ULiège)
Full Text
Peer Reviewed
See detailDu trou de ver au trou de serrure...
Gernay, Delphine; Moukhaiber, Sophie; Maenhout, Marine et al

in Revue des Hôpitaux de Jour Psychiatriques et des Thérapies Institutionnelles (2017), 19

Detailed reference viewed: 42 (8 ULiège)
Full Text
See detailSans titre (postface)
Dejasse, Erwin ULiege

in Muñoz, José; Sampayo, Carlos (Eds.) Le Bar à Joe (édition intégrale) (2017)

Detailed reference viewed: 10 (2 ULiège)
Full Text
Peer Reviewed
See detailPraxis et anti-praxis des revues intellectuelles de l’immédiat après-guerre
Franck, Thomas ULiege

in Argumentation et Analyse du Discours (2017), 19

The sociodiscursive analysis of post-war intellectual reviews’ editorials, especially Socialisme ou Barbarie, gives rise to rhetorical and argumentative interpretations determined by the socio-historical ... [more ▼]

The sociodiscursive analysis of post-war intellectual reviews’ editorials, especially Socialisme ou Barbarie, gives rise to rhetorical and argumentative interpretations determined by the socio-historical context, by reviews’ editorial features and by the Marxist discursive formation. On the one hand the polemic dimension of these discourses (structured by a logic of ideological dispute), the reproduction of the fixed formula “marxisme véritable” and the use of ironical “îlots textuels” (parts of discourse that quote words of the opponent to discredit him) are all rhetorical examples of the influence of an intellectual discourse’s instituted state. On the other hand the militant ethos developed by Socialisme ou Barbarie and the presupposition of the link between Stalinism and State capitalism are parts of a discursive innovation. This dialectical logic between a discursive determination and a power of innovation has to be studied from a materialist point of view. Thus the dialectical movement between a discursive creation – for example the militant activism of Socialisme ou Barbarie – and a discourse’s instituted state – for example the Marxist dogmatism – must be understood on the basis of different materialist notions. Also the notion of “group praxis” allows to overpass this movement between determination and innovation. Consequently the possibility arises to think the rhetorical particularities and the critical process of intellectual reviews. [less ▲]

Detailed reference viewed: 27 (4 ULiège)
Full Text
Peer Reviewed
See detailClinical classification criteria for radicular pain caused by lumbar disc herniation: the radicular pain caused by disc herniation (RAPIDH) criteria
Genevay, Stéphane; Courvoisier, Delphine; Konstantinou, Kika et al

in Spine Journal (2017), 17(10), 1464-1471

BACKGROUND CONTEXT: Classification criteria are recommended for diseases that lack specific biomarkers to improve homogeneity in clinical research studies. Because imaging evidence of lumbar disc ... [more ▼]

BACKGROUND CONTEXT: Classification criteria are recommended for diseases that lack specific biomarkers to improve homogeneity in clinical research studies. Because imaging evidence of lumbar disc herniations (LDHs) may not be associated with symptoms, clinical classification criteria based on patient symptoms and physical examination findings are required. PURPOSE: This study aimed to produce clinical classification criteria to identify patients with radicular pain caused by LDH. STUDY DESIGN: The study design was a two-stage process. Phase 1 included a Delphi process and Phase 2 included a cohort study. PATIENT SAMPLE: The patient sample included outpatients recruited from spine clinics in five countries. OUTCOME MEASURES: The outcome measures were items from history and physical examination. MATERIALS AND METHODS: In Phase 1, 17 spine experts participated in a Delphi process to select symptoms and signs suggesting radicular pain caused by LDH. In Phase 2, 19 different clinical experts identified patients they confidently classified as presenting with (1) radicular pain caused by LDH, (2) neurogenic claudication (NC) caused by lumbar spinal stenosis, or (3) non-specific low back pain (NSLBP) with referred leg pain. Patients completed survey items and specialists documented examination signs. A score to predict radicular pain caused by LDH was developed based on the coefficients of the multivariate model. An unrestricted grant of less than US$15,000 was received from MSD: It was used to support the conception of the Delphi, data management, and statistical analysis. No fees were allocated to participating spine specialists. RESULTS: Phase 1 generated a final list of 74 potential symptoms and signs. In Phase 2, 209 patients with pain caused by LDH (89), NC (63), or NSLBP (57) were included. Items predicting radicular pain caused by LDH (p<.05) were monoradicular leg pain distribution, patient-reported unilateral leg pain, positive straight leg raise test <60° (or femoral stretch test), unilateral motor weakness, and asymmetric ankle reflex. The score had an AUC of 0.91. An easy-to-use weighted set of criteria with similar psychometric characteristics is proposed (specificity 90.4%, sensitivity 70.6%). CONCLUSIONS: Classification criteria for identifying patients with radicular pain caused by LDH are proposed. Their use could improve the homogeneity of patients enrolled in clinical research studies. [less ▲]

Detailed reference viewed: 60 (5 ULiège)