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Last 7 days
An XMM-Newton view of the M 17 nebulaMernier, François ; Rauw, Grégor ![]() in New Astronomy (2013), 20 We present the analysis of an XMM-Newton observation of the M 17 nebula. The X-ray point source population consists of massive O-type stars and a population of probable low-mass pre-main sequence stars ... [more ▼] We present the analysis of an XMM-Newton observation of the M 17 nebula. The X-ray point source population consists of massive O-type stars and a population of probable low-mass pre-main sequence stars. CEN 1a,b and OI 352, the X-ray brightest O-type stars in M 17, display hard spectra (kT of 3.8 and 2.6 keV) consistent with a colliding wind origin in binary/multiple systems. We show that the strong interstellar reddening towards the O-type stars of M 17 yields huge uncertainties on their L[SUB]X[/SUB]/L[SUB]bol[/SUB] values. The low-mass pre-main sequence stars exhibit hard spectra resulting from a combination of high plasma temperatures and very large interstellar absorption. We find evidence for considerable long term (months to years) variability of these sources. M 17 is one of the few star formation complexes in our Galaxy producing diffuse X-ray emission. We analyze the spectrum of this emission and compare it with previous studies. Finally, we discuss the Optical Monitor UV data obtained simultaneously with the X-ray images. We find very little correspondence between the UV and X-ray sources, indicating that the majority of the UV sources are foreground stars, whilst the bulk of the X-ray sources are deeply embedded in the M 17 complex. [less ▲] Detailed reference viewed: 22 (4 ULg) A massive parsec-scale dust ring nebula around the yellow hypergiant Hen 3-1379Hutsemekers, Damien ; ; Vamvatira-Nakou, Chloi ![]() in Astronomy and Astrophysics (2013), 552 On the basis of far-infrared images obtained by the Herschel Space Observatory, we report the discovery of a large and massive dust shell around the yellow hypergiant Hen 3-1379. The nebula appears as a ... [more ▼] On the basis of far-infrared images obtained by the Herschel Space Observatory, we report the discovery of a large and massive dust shell around the yellow hypergiant Hen 3-1379. The nebula appears as a detached ring of 1 pc diameter which contains 0.17 M[SUB]&sun;[/SUB] of dust. We estimate the total gas mass to be 7 M[SUB]&sun;[/SUB], ejected some 1.6 × 10[SUP]4[/SUP] years ago. The ring nebula is very similar to nebulae found around luminous blue variables (LBVs) except it is not photoionized. We argued that Hen 3-1379 is in a pre-LBV stage, providing direct evidence that massive LBV ring nebulae can be ejected during the red supergiant phase. [less ▲] Detailed reference viewed: 16 (6 ULg) Dual Formulations for Accurate Thin Shell Models in a Finite Element Subproblem MethodDang, Quoc Vuong ; Dular, Patrick ; Vazquez Sabariego, Ruth et alin Proceeding of the 19th COMPUMAG Conference on the Computation of Electromagnetic Fields, 2013 (2013, April 01) A subproblem finite with dual finite element magnetostatic and magnetodynamic formulations is developed for correcting the inaccuracies near edges and corners coming from thin shell models, that replace ... [more ▼] A subproblem finite with dual finite element magnetostatic and magnetodynamic formulations is developed for correcting the inaccuracies near edges and corners coming from thin shell models, that replace thin volume regions by surfaces. The surface-to-volume correction problem is defined as one of the multiple subproblems applied to a complete problem, considering successive additions of inductors and magnetic or conducting regions, some of these being thin regions. Each SP requires a proper adapted mesh of its regions, which facilitates meshing and increases computational e ciency. [less ▲] Detailed reference viewed: 21 (3 ULg) Fast-evolving weather for the coolest of our two new substellar neighboursGillon, Michaël ; ; Jehin, Emmanuel et alE-print/Working paper (2013) We present the results of an intense photometric monitoring in the near-infrared (~0.9 microns) with the TRAPPIST robotic telescope of the newly discovered binary brown dwarf WISE J104915.57-531906.1, the ... [more ▼] We present the results of an intense photometric monitoring in the near-infrared (~0.9 microns) with the TRAPPIST robotic telescope of the newly discovered binary brown dwarf WISE J104915.57-531906.1, the third closest system to the Sun at a distance of only 2 pc. Our twelve nights of photometric time-series reveal a quasi-periodic (P = 4.87+-0.01 h) variability with a maximal peak-peak amplitude of ~11% and strong night-to-night evolution. We attribute this variability to the rotational modulation of fast-evolving weather patterns in the atmosphere of the coolest component (~T1-type) of the binary. No periodic signal is detected for the hottest component (~L8-type). For both brown dwarfs, our data allow us to firmly discard any unique transit during our observations for planets >= 2 Rearth. For orbital periods smaller than ~9.5 h, transiting planets are excluded down to an Earth-size. [less ▲] Detailed reference viewed: 2 (0 ULg) WASP-64b and WASP-72b: two new transiting highly irradiated giant planetsGillon, Michaël ; ; et alin Astronomy and Astrophysics (2013), 552 We report the discovery by the WASP transit survey of two new highly irradiated giant planets. WASP-64 b is slightly more massive (1.271 ± 0.068 MJup) and larger (1.271 ± 0.039 RJup) than Jupiter, and is ... [more ▼] We report the discovery by the WASP transit survey of two new highly irradiated giant planets. WASP-64 b is slightly more massive (1.271 ± 0.068 MJup) and larger (1.271 ± 0.039 RJup) than Jupiter, and is in very-short (a = 0.02648 ± 0.00024 AU, P = 1.5732918 ± 0.0000015 days) circular orbit around a V = 12.3 G7-type dwarf (1.004 ± 0.028 Msun, 1.058 ± 0.025 Rsun, Teff = 5500 ± 150 K). Its size is typical of hot Jupiters with similar masses. WASP-72 b has also a mass a bit higher than Jupiter's (1.461-0.056+0.059 MJup) and orbits very close (0.03708 ± 0.00050 AU, P = 2.2167421 ± 0.0000081 days) to a bright (V = 9.6) and moderately evolved F7-type star (1.386 ± 0.055 Msun, 1.98 ± 0.24 Rsun, Teff = 6250 ± 100 K). Despite its extreme irradiation (~5.5 × 109 erg s-1 cm-2), WASP-72 b has a moderate size (1.27 ± 0.20 RJup) that could suggest a significant enrichment in heavy elements. Nevertheless, the errors on its physical parameters are still too high to draw any strong inference on its internal structure or its possible peculiarity. [less ▲] Detailed reference viewed: 10 (1 ULg) Mise en oeuvre du Programme de Gestion Durable de l'Azote à l'échelle de deux petits bassins versants (Arquennes - Belgique) et évaluation d'impact par le suivi des flux de nitrate aux exutoires et par modélisation numériqueDeneufbourg, Mathieu ; Vandenberghe, Christophe ; et alin Vandenberghe, Christophe; Colinet, Gilles; Destain, Jean-Pierre (Eds.) et al 2ème Atelier Nitrate - Eau. Evaluation du Programme de Gestion Durable de l'Azote (2013) Four water catchments used by the Walloon Society of Water (SWDE) in the rural village of Arquennes (Province of Hainaut, Belgium) have been contaminated by nitrate (concentrations between 60 and 70 mg ... [more ▼] Four water catchments used by the Walloon Society of Water (SWDE) in the rural village of Arquennes (Province of Hainaut, Belgium) have been contaminated by nitrate (concentrations between 60 and 70 mg NO3-·l-1) for several years. The catchment basins (31 ha and 47 ha) are located exclusively in a cultivated area on loamy soils. Since October 2004, these basins have been used as a pilot area for the environmental evaluation of good agricultural practices as regards nitrogen management (adaptation of amounts of mineral nitrogen fertilizers, farm manure management, soil cover after harvest, etc.) thanks to monitoring by farmers. This approach fits into the general pattern of the Sustainable Nitrogen Management Program (PGDA in French), which implements the European Nitrates Directive as part of Walloon legislation. The second objective of the working scheme is to study and to set up a decision-making tool aimed at preventing the contamination of water by agricultural nitrate around water catchments. Two numerical models (SWAT and FEFLOW®) were used together in order to simulate the passage of water and nitrogen from the soil surface to the water catchments outlets. Calibration and validation of models were based, among other things, on soil and subsoil characterization and on tracer testing in both saturated and unsaturated zones. Moreover crop yield, farming practices, water and nitrate fluxes in water catchments, groundwater levels and nitrate concentration in groundwater were monitored for eight years. The results of simulations show that the application of PGDA in Arquennes watersheds would lead to a decrease in nitrate concentration (to almost 50 mg NO3-·l-1) in water catchments in 2012. This expected improvement in water quality has been visible since 2009 in water catchments, with mean nitrate concentrations of lower than 50 mg NO3-·l-1 at the end of 2012. [less ▲] Detailed reference viewed: 13 (2 ULg) Les empereurs julio-claudiens et les lettres grecquesRochette, Bruno ![]() Conference (2013, April) Detailed reference viewed: 9 (0 ULg) Gestion durable de l'azote au-delà de la seule problématique "nitrate"Bodson, Bernard ; Vandenberghe, Christophe ![]() in Vandenberghe, Christophe; Colinet, Gilles; Destain, Jean-Pierre (Eds.) et al 2ème Atelier Nitrate - Eau. Evaluation du Programme de Gestion Durable de l'Azote (2013) The aim of the sustainable management of nitrogen is to reduce dramatically the risk of nitrogen leaching into groundwater. Regulations and recommendations have resulted in a more judicious use of manure ... [more ▼] The aim of the sustainable management of nitrogen is to reduce dramatically the risk of nitrogen leaching into groundwater. Regulations and recommendations have resulted in a more judicious use of manure as a mineral fertilizer to benefit both the environment and farmers. Rehabilitating leguminous plants into our rotations and our forage areas needs to become a priority. These plants can partially substitute for imported soya and, at the same time, synthesize the free nitrogen available to plants. Management of intercropping and in particular of catch crops can no longer be limited to the single issue of nitrate in water. Integrated crop protection and risk reduction of greenhouse gas emissions also need to be taken into account and flexibility needs to be incorporated into the implementation of these intercropping rules. [less ▲] Detailed reference viewed: 10 (1 ULg) Compte-rendu de l'ouvrage de A. Beyaert-Geslin: Sémiotique du designDondero, Maria Giulia ![]() in Questions de Communication (2013), 23 Detailed reference viewed: 4 (0 ULg) Le religieux et le sacré vus à travers l’iconographie de l’olfactionDondero, Maria Giulia ![]() in Questions de Communication (2013), 23 This article explores the representation of olfactory sensoriality in modern religious painting as conveyed by the movement of clouds, and thus raises the question of the relationship between the ... [more ▼] This article explores the representation of olfactory sensoriality in modern religious painting as conveyed by the movement of clouds, and thus raises the question of the relationship between the religious dimension of faith and the sacred contagion of transcendence. The representation of olfaction in pictorial iconography is compared with the disappearance of the holy bodies in contemporary artistic photography and perfume advertising. Interpretive propositions about the distinction of the religious and the sacred in relation to three corpuses are developed with a semiotic methodology. [less ▲] Detailed reference viewed: 12 (0 ULg) Contrôle de l'azote potentiellement lessivable dans le sol en début de période de lixiviation. Etablissement des valeurs de référenceVandenberghe, Christophe ; ; et alin Vandenberghe, Christophe; Colinet, Gilles; Destain, Jean-Pierre (Eds.) et al 2ème Atelier Nitrate - Eau. Evaluation du Programme de Gestion Durable de l'Azote (2013) Based on observations in the field, for ten years, Gembloux Agro-Bio Tech (ULg) and the Catholic University of Louvain set annual benchmarks for nitrate-nitrogen concentrations in the soil at the ... [more ▼] Based on observations in the field, for ten years, Gembloux Agro-Bio Tech (ULg) and the Catholic University of Louvain set annual benchmarks for nitrate-nitrogen concentrations in the soil at the beginning of the leaching period (referred to as ‘PLN’ - Potentially Leachable Nitrogen). These values are used as a reference to monitor farmers located in vulnerable zones, with the monitoring being carried out by the Public Service of Wallonia. Soil samples were taken twice a year (October and December) from approximately 250 plots subjected to reasoned nitrogen fertilization. The plots were located within 34 reference farms (constituting the Agricultural Survey Areas). The samples were then analyzed for nitrate-nitrogen content. The results allowed to establish reference values for eight classes of cultivation or meadow. Analysis of the results recorded in 2011, as in previous years, illustrates the importance of “crop” and “year” in establishing reference values. [less ▲] Detailed reference viewed: 16 (5 ULg) Bio-Objects' Political Capacity: A Research Agenda; Hendrickx, Kim ; et alin Croatian Medical Journal (2013), 54 This article explores the merits of foregrounding the dichotomy of politicization vs de-politicization for our understanding of bio-objects in order to study their production, circulation, and governance ... [more ▼] This article explores the merits of foregrounding the dichotomy of politicization vs de-politicization for our understanding of bio-objects in order to study their production, circulation, and governance in European societies. By asking how bio-objects are configured in science, policy, public, and media discourses and practices, we focus on the role of socio-technical configurations in generating political relations. The bio-object thereby serves as an entry point to approach and conceptualize “the political” in an innovative way. Drawing from our previous work, which uses the concepts of de-politicization and (re-)politicization, this paper puts forward a research agenda for studying the political relations generated by specific socio-technical configurations of bio-objects. [less ▲] Detailed reference viewed: 2 (1 ULg) Mise en oeuvre de la révision du Programme d'action lié à la Directive NitratesVandenberghe, Christophe ; Colinet, Gilles ; Destain, Jean-Pierre et alin Vandenberghe, Christophe; Colinet, Gilles; Destain, Jean-Pierre (Eds.) et al 2ème Atelier Nitrate - Eau Evaluation du Programme de Gestion Durable de l'Azote (2013) Detailed reference viewed: 9 (1 ULg) Suivi de la lixiviation du nitrate en plein champ par la technique lysimétrique : retour de huit années d'expérienceDeneufbourg, Mathieu ; Vandenberghe, Christophe ; et alin Vandenberghe, Christophe; Colinet, Gilles; Destain, Jean-Pierre (Eds.) et al 2ème Atelier Nitrate - Eau. Evaluation du Programme de Gestion Durable de l'Azote (2013) Since 2003, nitrate leaching has been monitored in six plots located in a loamy area (Hesbaye, Belgium), mainly dedicated to wheat, sugarbeet and vegetable crops. Open-field lysimeters have been used in ... [more ▼] Since 2003, nitrate leaching has been monitored in six plots located in a loamy area (Hesbaye, Belgium), mainly dedicated to wheat, sugarbeet and vegetable crops. Open-field lysimeters have been used in order not to impede agricultural operations. Lysimeters are used as follow-up tools to quantify the amounts of nitrate leaching below the root zone. This study aims to evaluate the suitability of PLN (Potentially Leachable Nitrogen – APL in French) defined in the Sustainable Nitrogen Management Program (PGDA in French) as an environmental indicator by relating nitrogen management practices (including fertilization recommendations) to PLN values and groundwater quality. This study demonstrates that lysimeters are efficient in collecting representative amounts of leaching water. Lysimeters show that PLN is identified as being related to the nitrate content in leaching water, which will not be taken up by the next crop. The amount of nitrate leaching below the root zone demonstrates the necessity and the relevance of the organic nitrogen spreading limits defined in the Sustainable Nitrogen Management Program. The lysimeter tool also shows that respect for leaching water quality standards under agricultural plots needs to be considered from an integrated and generalized approach, taking into account complete crop sequences and rotations, including rational fertilization rates and the introduction of catch crops in rotation. Some suitable or unsuitable crop sequences with regard to good groundwater quality are listed. [less ▲] Detailed reference viewed: 9 (1 ULg) Evaluation du troisième Programme de Gestion Durable de l'Azote en agriculture. Recommandations en matière de règlementations et de recherches scientifiquesVandenberghe, Christophe ; Destain, Jean-Pierre ; Beckers, Yves et alin Vandenberghe, Christophe; Colinet, Gilles; Destain, Jean-Pierre (Eds.) et al 2ème Atelier Nitrate - Eau. Evaluation du Programme de Gestion Durable de l'Azote (2013) In accordance with the Nitrates Directive, the third “Durable Nitrogen Management Plan” (PGDA) will be soon reviewed in Wallonia (Belgium). The second “Nitrate – Water” workshop took place between 28th ... [more ▼] In accordance with the Nitrates Directive, the third “Durable Nitrogen Management Plan” (PGDA) will be soon reviewed in Wallonia (Belgium). The second “Nitrate – Water” workshop took place between 28th May and 1st June 2012. The workshop was attended by both Belgian scientists (Université catholique de Louvain - UCL, Walloon Agricultural Research Center CRA-W, Université de Liège - ULg, Gembloux Agro-Bio Tech) and French scientists (National Institute for Agricultural Research - INRA). In the light of the results of experiments presented by scientists at this workshop, modifications to the PGDA are now recommended. These concern organic and mineral nitrogen fertilization for crops and meadows; catch crops; soil nitrate-nitrogen residue limitation in autumn, at the start of the nitrate leaching period; the management of meadow ploughing and a modification of the dairy cow standard for nitrogen production. [less ▲] Detailed reference viewed: 19 (6 ULg) Modélisation numérique hydrosédimentaire au service de la gestion durable des sédimentsDewals, Benjamin ; Erpicum, Sébastien ; Archambeau, Pierre et alin Recyclage et Valorisation (2013), 41 La gestion des sédiments revêt une importance croissante pour l’exploitation des voies navigables et nombre de projets de construction de barrages et de complexes hydroélectriques. L’impact des apports en ... [more ▼] La gestion des sédiments revêt une importance croissante pour l’exploitation des voies navigables et nombre de projets de construction de barrages et de complexes hydroélectriques. L’impact des apports en matériaux solides se manifeste tant par des effets à long terme, telle la réduction de la capacité du réservoir, que par des conséquences à plus court terme, telle l’usure prématurée des turbines. L’étude détaillée des effets sédimentaires s’impose donc de plus en plus tôt dans la conception de nouveaux aménagements. Elle est aussi un objectif tout au long de l’exploitation des ouvrages, dans une perspective de gestion sécuritaire et durable. [less ▲] Detailed reference viewed: 25 (10 ULg) High energy environment offshore deposits in the western Gulf of Corinth, GreeceBeckers, Arnaud ; ; et alConference (2013, April) Detailed reference viewed: 22 (8 ULg) Late Pleistocene to Present - normal and strike slip - faulting in the western Gulf of Corinth; data from high resolution seismic reflection SISCOR surveysBeckers, Arnaud ; Bodeux, Sarah ; et alConference (2013, April) Detailed reference viewed: 13 (4 ULg) Strontium ranelate improves osteoarthritis symptoms compared to placebo in patients with knee OA: The SEKOIA studyBruyère, Olivier ; ; et alin Osteoporosis International (2013, April), 24(Suppl.1), 49-51 Detailed reference viewed: 17 (3 ULg) What is the value of biomarkers for drug development in osteoarthritis?; ; et al in Osteoporosis International (2013, April), 24(Suppl.1), 77-78 Detailed reference viewed: 6 (2 ULg) |
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