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See detailReal-time measurement of temperature variation during nanosecond pulsed laser induced contamination deposition
Kokkinos, Dimitrios ULg; Gailly, Patrick ULg; Georges, Marc ULg et al

in Applied Optics (2015), 54(36), 10579

In this paper a study of the heat generation during UV Laser Induced Contamination (LIC) and potentially resulting subsequent thermal damage is presented. This becomes increasingly interesting when optics ... [more ▼]

In this paper a study of the heat generation during UV Laser Induced Contamination (LIC) and potentially resulting subsequent thermal damage is presented. This becomes increasingly interesting when optics with delicate coatings are involved. During LIC radiation can interact with outgassing molecules both in the gas phase and at the surface, triggering chemical and photo-fixation reactions. This is a major hazard, in particular for laser units operating under vacuum conditions such as for space applications. The intense photon flux not only affects the contaminant deposition rate but also alters their chemical structure that can increase their absorption coefficient. Over cumulative irradiation shots these molecules formed deposits that increasingly absorb photons and produce heat as a by-product of de-excitation eventually leading to thermal damage. One could better asses the risk of the latter with the knowledge of temperature during the contamination process. For this purpose thermoreflectance technique is used here to estimate the temperature variation from pulse to pulse during contamination deposition through the analysis of a temperature-dependent surface reflectance signal. [less ▲]

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See detailUne minorité à la recherche d'elle-même: les Belges germanophones de 1945 à 1973
Brüll, Christoph ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 33 (3 ULg)
See detailStudying ‘décret mémoire’ of the French Community of Belgium.
Nossent, Jérôme ULg

Conference (2015, December 18)

On the 13th March 2009, Belgium’s French Community (currently named the Wallonia-Brussels Federation (WBF)) parliament, adopted the “décret mémoire” (decree of remembrance). This deed shows Belgian public ... [more ▼]

On the 13th March 2009, Belgium’s French Community (currently named the Wallonia-Brussels Federation (WBF)) parliament, adopted the “décret mémoire” (decree of remembrance). This deed shows Belgian public authorities’ will to mark their presence in the memorial field. The decree organizes the recognition and the financing of multiple actors and institutions by the authorities, through a structure and a hitherto unseen way of functioning. Among its activities, the decree organizes yearly calls for projects, whose recipients are non-profit-making organizations and educational institutions that are either organized or subsidised by the WBF. The organisation set in place by the decree of remembrance appears to be a “political use of the past”. That means that some past events are chosen and promoted to give meaning to the individual memory, in a collective intent. This way of doing comes from the political will to organize the representation of one common past, aiming to bring out themes that carry particular values. Consequently, is it possible to study the power that the decree actually gives to the public authorities? Does it allow them to constrain or to influence other actors of their memory field? If that is the case, how could it be possible to demonstrate it? We suggest trying to find an answer to these interrogations through a case study concerning the 2014 calls for projects of the year. [less ▲]

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See detailA herpesvirus alters the behavior of its host to enhance its replication
Ronsmans, Maygane ULg

Conference (2015, December 18)

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See detailAssessing the Risk of Ecosystem Disruption in Europe using a Dynamic Vegetation Model driven by CMIP5 Regional Climatic Projections from EURO-CORDEX
Dury, Marie ULg; Hambuckers, Alain ULg; Henrot, Alexandra-Jane ULg et al

Conference (2015, December 18)

While the combination of warmer and drier mean climatic conditions can have severe impacts on ecosystems, extreme events like droughts or heat waves that break the gradual climate change can have more ... [more ▼]

While the combination of warmer and drier mean climatic conditions can have severe impacts on ecosystems, extreme events like droughts or heat waves that break the gradual climate change can have more long-term consequences on ecosystem composition, functioning and carbon storage. Hence, it is essential to assess the changes in climatic variability and the changes in frequency of extreme events projected for the future. Ecosystems could not be in a condition to adapt to these new conditions and might be disrupted. Here, the process-based dynamic vegetation model CARAIB DVM was used to evaluate and analyze how future climate and extreme events will affect European ecosystems. To quantify the uncertainties in the climatic projections and in their potential impacts on ecosystems, the vegetation model was driven with the outputs of different regional climatic models (RCMs), nested in CMIP5 GCM projections for the EURO-CORDEX project. We used the ALADIN version 5.3 (Météo-France/CNRM) and other EURO-CORDEX RCMs. These climatic projections are at a high spatial resolution (0.11-degree, ~12 km). CARAIB simulations were performed across Europe over the historical period 1951-2005 and the future period 2006-2100 under RCP4.5 and RCP8.5 emission scenarios. We simulated a set of 99 individual species (47 herbs, 12 shrubs and 40 trees) representing the major European ecosystem flora. First, we analyzed the climatic variability simulated by the climatic models over the historical period and compared it with the observed climatic variability. None of these climatic models can reproduce accurately the present natural climatic variability. Then, to assess the risk of ecosystem disruption in the future and to identify the vulnerable areas in Europe, we created an index combining several CARAIB outputs: runoff, mean NPP, soil turnover, burned area, appearance and disappearance of species. We evaluated the severity of change projected for these variables (period 2071-2100) relative to their current variability (period 1961-1990). Mean changes were considered severe if they exceed observed variability. The highest values of the index were found in southern Europe, indicating that the amplitude of the expected ecosystem changes largely exceeds current interannual variability in this area. [less ▲]

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See detailPrediction of the post-dilution hematocrit during cardiopulmonary bypass. Are new formulas needed?
ERPICUM, Marie ULg; Dardenne, Nadia ULg; HANS, Grégory ULg et al

in Perfusion (2015)

Objectives: Predicting the post-dilution hematocrit is an important tool to avoid preventable anemia or unnecessary transfusion. Simplified empirical formulas currently used for such a prediction may lead ... [more ▼]

Objectives: Predicting the post-dilution hematocrit is an important tool to avoid preventable anemia or unnecessary transfusion. Simplified empirical formulas currently used for such a prediction may lead to large errors. We aimed to improve the accuracy of these formulas by a better estimation of the dilution volume and the patient circulatory blood volume. Methods: We compared the estimation accuracy of two formulas, using fixed (formula A) versus estimated (formula D) dilution volume and patient circulatory blood volume for 100 cardiac interventions. The difference between predicted and measured HctT1 was considered as “good” if less than 0.5%, “moderate” between 0.5 and 2% and “poor” if higher than 2%. The influence of the body mass index (BMI) on patient blood volume estimation was explored by categorized groups’ comparison. Results: The mean difference between predicted and measured HctT1 differed significantly between formulas A and D. Formula A didn’t differ from HctT1 (p=0.19, IC95% [-0.89-0.18]), but a significant and higher underestimation was observed in the BMI⩽25 group compared to the other BMI groups (p<0.001). Formula D overestimated HctT1 (p<0.001, IC95% [1.01-1.93]) without a difference between the BMI groups. No difference was observed in their overall proportions of good (11 vs 10%), moderate (44 vs 46%) and poor predictions (47 vs 44%) (p=0.117). Conclusions: Formulas used for post-dilution hematocrit prediction lead to major estimation errors and a risk of inadequate transfusion practices. Estimations performed by experienced clinicians could not minimize these biases in all clinical cases as significant errors remain, with potential clinical impact. No estimation formula should be used as a hard tool for transfusing patients, but rather as a guide to predicting the probability of transfusion requirement. [less ▲]

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See detailHeat tracer and solute tests in an alluvial aquifer: field experiment and inverse modelling
Dassargues, Alain ULg; Klepikova, Maria; Jamin, Pierre ULg et al

Poster (2015, December 18)

Using heat as an active tracer in different types of aquifers is a topic of increasing interest. In this study, we investigate the potential interest of using heat tracer tests for characterization of a ... [more ▼]

Using heat as an active tracer in different types of aquifers is a topic of increasing interest. In this study, we investigate the potential interest of using heat tracer tests for characterization of a shallow alluvial aquifer. A thermal tracer test was conducted in the alluvial aquifer of the Meuse River, Belgium. The tracing experiment consisted in simultaneously injecting heated water and a dye tracer in a piezometer and monitoring the evolution of groundwater temperature and tracer concentration in the recovery well and in monitoring wells. To get insights in the 3D characteristics of the heat transport mechanisms the space-filling arrangement of observation wells was used. The breakthrough curves measured in the recovery well showed that heat transfer in the alluvial aquifer is slower and more dispersive than solute transport. Recovery is very low for heat while in the same time it is measured as relatively high for the solute tracer. This is due to the fact that heat diffusion is larger than molecular diffusion, implying that exchange between groundwater and the porous medium matrix is far more significant for heat than for solute tracers. Temperature breakthrough curves in other piezometers are contrasted with what would be expected in an ideal layered aquifer. They reveal strongly unequal lateral and vertical components of the transport mechanisms. The observed complex behavior of the heat plume was explained by the groundwater flow gradient on the site and heterogeneities of hydraulic conductivity field. By using numerical model of heat and flow coupled with pilot points inverse approach main preferential paths were characterized. [less ▲]

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See detailReconnaissance et parentification: des mots qui vont si bien ensemble?
Haxhe, Stéphanie ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 50 (4 ULg)
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See detailCompte rendu - 28th Australian Conference in Banking and Finance
Lambert, Marie ULg; Fays, Boris ULg; Hübner, Georges ULg

Conference (2015, December 18)

Fama and French risk premiums do not reliably estimate the magnitude of the size or book-to-market effects, inducing many researchers to inflate the number of factors. We object that controlling ex ante ... [more ▼]

Fama and French risk premiums do not reliably estimate the magnitude of the size or book-to-market effects, inducing many researchers to inflate the number of factors. We object that controlling ex ante for noise in the estimation procedure enables to keep a parsimonious set of factors. We replace Fama and French’s independent rankings with the conditional ones introduced by Lambert and Hübner (2013). This alternative framework generates much stronger “turn-of-the-year” size and “through-the-year” book-to-market effects than conventionally documented. Furthermore, the factors deliver less specification errors when used to price portfolios, especially regarding the “small angels” (low size – high BTM stocks). [less ▲]

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See detailLa terre creuse, de la géologie à la fiction. Postérité d’un chronotope d’anticipation à partir de Jules Verne
Stienon, Valérie ULg

Conference (2015, December 18)

Le voyage au centre de la Terre a été magistralement imaginé par Jules Verne en 1864 avant de devenir un véritable topos de la littérature populaire et de jeunesse. Sa postérité s’illustre dans les ... [more ▼]

Le voyage au centre de la Terre a été magistralement imaginé par Jules Verne en 1864 avant de devenir un véritable topos de la littérature populaire et de jeunesse. Sa postérité s’illustre dans les multiples déclinaisons de la terre creuse, recensées notamment par Guy Costes et Joseph Altairac dans leur bibliographie commentée en 2006. En quoi ce motif plus communément associé à une atemporalité (monde perdu, histoire secrète) ou à une régression temporelle (monde sauvage, vie des cavernes) intervient-il aussi dans une écriture de l’anticipation ? Chez Verne lui-même, il s’agit à la fois d’un voyage à rebours dans le temps, chaque strate parcourue correspondant à un recul historique, et d’une expédition scientifique déployant une technologie et des connaissances novatrices. Ce motif topique semble donc porteur d’une ambiguïté temporelle féconde. La communication proposera un parcours transversal dans le corpus d’anticipation francophone allant d’Ignis (1883) de Didier de Chousy qui traite de l’exploitation d’une nouvelle énergie géothermique, le « feu central de la Terre », jusqu’à Régis Messac dont La Cité des Asphyxiés (1937) dépeint un monde intra-terrestre dystopique. Les reprises de la terre creuse permettent d’éclairer l’importance des filiations génériques, des supports partagés et des formules éditoriales à succès, mais elles mettent aussi en évidence des œuvres atypiques, traduisant de manière spécifique le discours social et scientifique de leur époque. Si Verne, ses épigones et d’autres auteurs d’anticipation ont pu être tentés de réinvestir la terre creuse en fiction à un moment où sa réalité n’est plus perçue comme crédible dans le champ scientifique, c’est sans doute en raison de l’intrication particulièrement dense des disciplines concernées (géographie, géologie, paléontologie, sciences naturelles) et de l’importance des idéologies qui ont pu les croiser et les dynamiser : positivisme, hygiénisme, colonialisme, craintes écologiques. Cette communication voudrait montrer comment le motif fécond de la terre creuse, dans son évolution complexe du plausible à l’irréel, passe d’une croyance à une théorie scientifique avant de se développer en chronotope littéraire. [less ▲]

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See detailThree-Parameter Kinematic Theory for Shear-Dominated Reinforced Concrete Walls: Implementation
Mihaylov, Boyan ULg; Hannewald, Pia; Beyer, Katrin

Software (2015)

The tree-parameter kinematic theory (3PKT) is aimed at addressing the need for physically accurate and computationally effective models for predicting the response of shear-dominated reinforced concrete ... [more ▼]

The tree-parameter kinematic theory (3PKT) is aimed at addressing the need for physically accurate and computationally effective models for predicting the response of shear-dominated reinforced concrete walls. The theory is based on a three-degree-of-freedom kinematic model for the deformation patterns in walls with aspect ratios smaller than approximately 3. In the kinematic model the wall is divided into two parts - a rigid block and a fan of struts - by a diagonal crack. The mechanisms of shear resistance across this crack are modelled with non-linear springs to capture the pre- and post- peak shear behavior of the member. The base section of the wall is also modelled to account for yielding of the reinforcement and crushing of the concrete. The complete formulation of the 3PKT is presented in an ASCE Journal of Structural Engineering paper by Mihaylov, Hannewald and Beyer. The attached Matlab code represents an implementation of the 3PKT for time-efficient computation of the response of shear-dominated walls. The limits of applicability of the 3PKT and the code are defined in the ASCE paper. [less ▲]

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See detailEstimation of diet digestibility and intake by grazing ruminants through near infrared reflectance spectroscopy analysis of faeces. Application in various contexts of livestock production
Decruyenaere, Virginie ULg

Doctoral thesis (2015)

Grazing is the most economical feeding scheme for ruminants. Grazing management, however, is often difficult for breeders, particularly because of a lack of knowledge about grass availability and quality ... [more ▼]

Grazing is the most economical feeding scheme for ruminants. Grazing management, however, is often difficult for breeders, particularly because of a lack of knowledge about grass availability and quality. There are methods for assessing the quantitative and qualitative characteristics of grass, but they are difficult to apply in the case of grazing ruminants. Near infrared reflectance spectroscopy (NIRS) is based on the absorption of infrared light by organic matters to provide NIRS spectra. These NIRS spectra can be correlated with the chemical or biological composition of samples in order to develop calibrations that can be used as predictive models. The primary objective of this PhD thesis was to study the potential of NIRS applied to faeces (FNIRS) in order to predict the characteristics of the diets of grazing herbivores. The particular focus was on the in vivo organic matter digestibility, voluntary intake and botanical composition of ingested diets. The main results of the study show that FNIRS has great portential for estimating in vivo digestibility and voluntary intake by grazing ruminants and that faeces are a good indicator of ingested diets. Based on both large or small and varied databases, the results suggest that FNIRS spectral libraries could be developed for characterising ruminant feed intake. The accuracy of the FNIRS models in estimating in vivo digestibility and voluntary intake is similar to or better than that of other methods usually used to assess these parameters. FNIRS could also be used to predict ruminants’ diet composition in terms of plant species. These predictions should be used only for ranking, however, because of the current lack of accurate procedures for determining diet selection individually. NIRS applied to faeces can be used to predict the in vivo characteristics of forage with sufficient accuracy. The prediction error of NIRS calibrations depends on the accuracy and precision of the reference data. The prediction of in vivo digestibility and intake is sufficiently repeatable compared with the procedure using the reference method. Intake is more difficult to predict with sufficient precision and is more closely linked to animal variability and to uncertainty of the FNIRS models. The major difficulty in using this method lies in generating the diet-faecal pairs as reliably as possible. FNIRS calibrations for predicting in vivo diet characteristics are derivative calibrations. The sample analysed for reference values (diet samples) differs from the samples submitted to NIRS analyses (faeces). With regard to research on forages, in vivo trials with animals confined in pens or digestibility crates appears to be the best reference method for generating FNIRS calibrations. Future work will involve developing FNIRS calibrations for predicting independent datasets and using them to create decision-support tools for improving diverse grazing management schemes. The major focus should be to compare different feeding strategies rather than to obtain an exact estimate of feed intake values. As a low-cost and rapid prediction technique, FNIRS could contribute significantly to the development of a methodology that would help improve our knowledge of forage and animal variability. [less ▲]

Detailed reference viewed: 43 (4 ULg)
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See detailLe mythe de la donation de sens. Motivation de la noèse par le donné
Leclercq, Bruno ULg

Conference (2015, December 17)

Detailed reference viewed: 14 (0 ULg)
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See detailWater-Energy Nexus in Shared River Basins: How Hydropower Shapes Cooperation and Coordination
Kouangpalath, Phimthong ULg; Meijer, Karen

in Topical Issue on Sustainability in the Water-Energy-Food Nexus (2015), 2

The construction of hydropower plants on transboundary rivers is seldom done with equal benefits to all riparians, and therefore presents coordination and cooperation challenges. Without a supra-national ... [more ▼]

The construction of hydropower plants on transboundary rivers is seldom done with equal benefits to all riparians, and therefore presents coordination and cooperation challenges. Without a supra-national authority in charge of transboundary river basins, coordination between sectors (water, energy and environment) and cooperation between countries largely depends on willingness of the individual nation states and the power relations between these countries. This paper discusses how the interests and relative power positions of actors in transboundary water management shape the outcomes, and what roles are played by River Basin Organisations and foreign investors (especially in hydropower development). These issues are illustrated with examples from the Mekong river in Southeast Asia (Laos, Thailand, Cambodia and Vietnam), the Euphrates-Tigris (Turkey, Syria, Iraq, Iran and Kuwait) and the Çoruh in Turkey and Georgia. [less ▲]

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See detailEléments de compréhension du processus de radicalisation du point de vue de l'engagement individuel
Garcet, Serge ULg

Conference given outside the academic context (2015)

Detailed reference viewed: 35 (5 ULg)